Technical Report Documentation Page

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Cover:

West Texas thunderstorm (digital image by David B. Thompson, 2004).

1. Report No.

FHWA/TX–04/0–4194–3

2. Government Accession No. 3. Recipient's Catalog No.

4. Title and Subtitle

EMPIRICAL, DIMENSIONLESS, CUMULATIVE-RAINFALL 

HYETOGRAPHS DEVELOPED FROM 1959–86 STORM 

DATA FOR SELECTED SMALL WATERSHEDS IN TEXAS

5. Report Date

August 2004

6. Performing Organization Code

7. Author(s)

Tara Williams-Sether, William H. Asquith, David B. Thompson, 

Theodore G. Cleveland, and Xing Fang

8. Performing Organization Report No.

SIR 2004–5075

9. Performing Organization Name and Address

 U.S. Geological Survey

 Water Resources Division

 8027 Exchange Drive

 Austin, Texas 78754

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

Project 0–4194

12. Sponsoring Agency Name and Address

Texas Department of Transportation 

Research and Technology Implementation Office

4000 Jackson Ave., Bldg. 1

P.O. Box 5080

Austin, TX 78731

U.S. Geological Survey

Water Resources Division

8027 Exchange Drive

Austin, Texas 78754

13. Type of Report and Period Covered

 Research from 2001 to 2004

14. Sponsoring Agency Code

15. Supplementary Notes

Project conducted in cooperation with the Texas Department of Transportation and the Federal Highway Administration.

16. Abstract

A database of incremental cumulative-rainfall values for storms that occurred in urban and small rural 

watersheds in north and south central Texas during the period 1959 to 1986 was used to develop empirical, 

dimensionless, cumulative-rainfall hyetographs. Storm-quartile classifications were determined from the cumulative-rainfall values, which were divided into data groups on the basis of storm-quartile classification (first, 

second, third, fourth, and first through fourth combined), storm duration (0 to 6, 6 to 12, 12 to 24, 24 to 72, and 

0 to 72 hours), and rainfall amount (1 inch or more). Removal of long leading tails, in effect, shortened the storm 

duration and, in some cases, affected the storm-quartile classification. Therefore, two storm groups, untrimmed 

and trimmed, were used for analysis. The trimmed storms generally are preferred for interpretation. For a 12-

hour or less trimmed storm duration, approximately 49 percent of the storms are first quartile. For trimmed 

storm durations of 12 to 24 and 24 to 72 hours, 47 and 38 percent, respectively, of the storms are first quartile. 

For a trimmed storm duration of 0 to 72 hours, the first-, second-, third-, and fourth-quartile storms accounted 

for 46, 21, 20, and 13 percent of all storms, respectively.

The 90th-percentile curve for first-quartile storms indicated about 90 percent of the cumulative rainfall 

occurs during the first 20 percent of the storm duration. The 10th-percentile curve for first-quartile storms indicated about 30 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration. The 

90th-percentile curve for fourth-quartile storms indicated about 33 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration. The 10th-percentile curve for fourth-quartile storms indicated less 

than 5 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration.

Statistics for the empirical, dimensionless, cumulative-rainfall hyetographs are presented in the report 

along with hyetograph curves and tables. The curves and tables presented do not present exact mathematical 

relations but can be used to estimate distributions of rainfall with time for small drainage areas of less than about 

160 square miles in urban and small rural watersheds north and south central in Texas.

17. Key Words

Precipitation, Rainfall, Rainfall hyetograph, Small 

watershed, Texas

18. Distribution Statement

No restrictions.

19. Security Classif. (of report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of pages

125

22. Price

$4.00
Empirical, Dimensionless, CumulativeRainfall Hyetographs Developed From 

1959–86 Storm Data for Selected 

Small Watersheds in Texas

By Tara Williams-Sether, William H. Asquith, David B. Thompson,

Theodore G. Cleveland, and Xing Fang

U.S. Department of the Interior

U.S. Geological Survey

In cooperation with the Texas Department of Transportation

Scientific Investigations Report 2004–5075

(TxDOT Research Report 0–4194–3)
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2004

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to

reproduce any copyrighted materials contained within this report.

The contents of this report do not necessarily reflect the official view or policies of the Texas Department of

Transportation (TxDOT). This report does not constitute a standard, specification, or regulation.

Suggested citation:

Williams-Sether, Tara, Asquith, W.H., Thompson, D.B., Cleveland, T.G., and Fang, Xing, 2004, Empirical, dimensionless,

cumulative-rainfall hyetographs developed from 1959–86 storm data for selected small watersheds in Texas: U.S.

Geological Survey Scientific Investigations Report 2004–5075, 125 p.
iii

Contents

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Previous Hyetograph Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Research by Huff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Research by the Soil Conservation Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Research by Pani and Haragan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Empirical, Dimensionless, Cumulative-Rainfall Hyetographs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Supplement 1. Descriptive Information for Streamflow-Gaging Stations Represented in 

Hyetograph Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Supplement 2. Untrimmed Percentiles and Statistics for Empirical Hyetograph Analysis, 

1959–86 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

Supplement 3. Trimmed Percentiles and Statistics for Empirical Hyetograph Analysis, 

1959–86 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Supplement 4. Untrimmed and Smoothed Percentiles for Empirical Hyetograph Analysis, 

1959–86 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Supplement 5. Trimmed and Smoothed Percentiles for Empirical Hyetograph Analysis, 

1959–86 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Figures

1. Map showing locations of streamflow-gaging stations represented in hyetograph database . . . . . . 2

2. Graph showing median (50th-percentile) dimensionless hyetograph curves derived from 

point rainfall values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3. Graph showing median (50th-percentile) dimensionless hyetograph curves derived from 

areal rainfall values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4. Graph showing Soil Conservation Service Type II and Type III hyetograph curves . . . . . . . . . . . . . . . . . 5

5. Graph showing median (50th-percentile) dimensionless hyetograph curves for the southern 

High Plains of Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6. Graph showing median (50th-percentile), 10th-, and 90th-percentile composite dimensionless 

hyetograph curves for the southern High Plains of Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

7. Examples of untrimmed (A) and trimmed (B) hyetograph data files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

8. Graphs showing distribution of storm occurrences by storm duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

9. Graphs showing distribution of storm occurrences by storm-quartile classification . . . . . . . . . . . . . . . 10

10. Graph showing median (50th-percentile) dimensionless hyetograph curves for a storm 

duration of 0 to 72 hours and a rainfall total of 1 inch or more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

11. Graphs showing 10th- to 90th-percentile dimensionless hyetograph curves for a storm duration 

of 0 to 72 hours and a rainfall total of 1 inch or more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
iv

Tables

1. Example dimensionless hyetograph data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

2. Averages and ranges for cumulative-rainfall amounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3. Distribution of storm occurrence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4. Smoothed median (50th-percentile) distributions of rainfall with time for a storm duration of 

0 to 72 hours and a rainfall total of 1 inch or more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5. Selected percentiles for first- and second-quartile storms for a storm duration of 0 to 72 hours 

and a rainfall total of 1 inch or more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6. Selected percentiles for third- and fourth-quartile storms for a storm duration of 0 to 72 hours 

and a rainfall total of 1 inch or more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Conversion Factors 

Multiply By To obtain

Length

inch 25.4 millimeter

Area

square mile 2.590 square kilometer
Empirical, Dimensionless, CumulativeRainfall Hyetographs Developed From 

1959–86 Storm Data for Selected 

Small Watersheds in Texas

By Tara Williams-Sether1, William H. Asquith2, David B. Thompson3, Theodore G. Cleveland4,

and Xing Fang5

Abstract

A database of incremental cumulative-rainfall values 

for storms that occurred in small urban and rural watersheds 

in north and south central Texas during the period from 1959 to 

1986 was used to develop empirical, dimensionless, cumulative-rainfall hyetographs. Storm-quartile classifications were 

determined from the cumulative-rainfall values, which were 

divided into data groups on the basis of storm-quartile classification (first, second, third, fourth, and first through fourth combined), storm duration (0 to 6, 6 to 12, 12 to 24, 24 to 72, and 0 

to 72 hours), and rainfall amount (1 inch or more). Removal of 

long leading tails, in effect, shortened the storm duration and, in 

some cases, affected the storm-quartile classification. Therefore, two storm groups, untrimmed and trimmed, were used for 

analysis. The trimmed storms generally are preferred for interpretation. For a 12-hour or less trimmed storm duration, approximately 49 percent of the storms are first quartile. For trimmed 

storm durations of 12 to 24 and 24 to 72 hours, 47 and 38 percent, respectively, of the storms are first quartile. For a trimmed 

storm duration of 0 to 72 hours, the first-, second-, third-, and 

fourth-quartile storms accounted for 46, 21, 20, and 13 percent 

of all storms, respectively.

The 90th-percentile curve for first-quartile storms indicated about 90 percent of the cumulative rainfall occurs during

the first 20 percent of the storm duration. The 10th-percentile 

curve for first-quartile storms indicated about 30 percent of the 

cumulative rainfall occurs during the first 20 percent of the 

storm duration. The 90th-percentile curve for fourth-quartile 

storms indicated about 33 percent of the cumulative rainfall 

occurs during the first 20 percent of the storm duration. The 

10th-percentile curve for fourth-quartile storms indicated less 

than 5 percent of the cumulative rainfall occurs during the first 

20 percent of the storm duration.

Statistics for the empirical, dimensionless, cumulativerainfall hyetographs are presented in the report along with 

hyetograph curves and tables. The curves and tables presented 

do not present exact mathematical relations but can be used to 

estimate distributions of rainfall with time for small drainage 

areas of less than about 160 square miles in urban and small 

rural watersheds in north and south central Texas.

Introduction

Knowledge of the distribution of rainfall with time is 

important for addressing hydrologic problems such as the 

design of culverts for small rural watersheds and the design of 

urban storm-sewer systems. This knowledge also is useful for 

studying soil erosion, studying the flood potential of various 

types of rainfall events, and advancing the general understanding of the physics of the atmosphere with regard to precipitation 

processes (Huff, 1967). To obtain knowledge about the distribution of rainfall in Texas, synthetic distributions presently 

(2003) are constructed using rainfall hyetographs by the Soil 

Conservation Service (1973). These hyetographs, which are 

graphical representations of rainfall with time, are an important 

element of numerous hydraulic designs throughout Texas and 

are used in conjunction with unit hydrographs (Chow and 

others, 1988; Haan and others, 1994) to obtain peak-discharge 

estimates and hydrograph shapes used for hydraulic design 

applications. An increase in the reliability of peak-discharge 

estimates can help engineers and others develop more costeffective drainage designs. 

1 U.S. Geological Survey, Bismarck, North Dakota.

2 U.S. Geological Survey, Austin, Texas.

3 Texas Tech University, Lubbock, Texas.

4 University of Houston, Houston, Texas.

5 Lamar University, Beaumont, Texas.
2 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Figure 1. Locations of streamflow-gaging stations represented in hyetograph database. (From Asquith and others, 2003.) 

32°

28°

104°

100°

96° 96°

98°

100°

32°

34°

30°

36°

EXPLANATION

Streamflow-gaging station

Basin boundary

TEXAS

Big

Spring

Fort

Worth

Fort Worth

Dallas

Dallas

Waco

Waco

Austin

Austin

San

Antonio

San Antonio

Map Base Information

Albers Projection

Basins from Texas Water Development Board

Cities from Texas Natural Resources Information System

Trinity River Basin

Brazos River Basin

Colorado River Basin

San Antonio

River Basin

0 100 200 MILES

To determine if the rainfall hyetographs (Soil Conservation Service, 1973) presently used by the Texas Department of 

Transportation (TxDOT) are representative of Texas storms and 

to provide a new procedure to develop hyetographs if the 

present hyetographs are not representative, the U.S. Geological 

Survey (USGS) in 2000, in cooperation with TxDOT and in 

collaboration with Texas Tech University, the University of 

Houston, and Lamar University, began a multicomponent 

study of the characteristics of rainfall in Texas. The purpose of 

this study, which is part of the larger multicomponent study, 

was to develop empirical, dimensionless, cumulative-rainfall 

hyetographs using procedures similar to those given by Huff 

(1967, 1990). Storm-quartile classifications were determined 

from cumulative-rainfall values for small watersheds in Texas. 

The cumulative-rainfall values then were divided into data 

groups based upon storm quartiles, storm durations, and rainfall 

totals of 1 inch or more. This report presents the empirical, 

dimensionless, cumulative-rainfall hyetographs developed during the study.

Database

The database used for this study was developed from 

ongoing, collaborative, rainfall-runoff research projects 

sponsored by TxDOT and the USGS. The ongoing research 

projects are being conducted by Texas Tech University, the 

University of Houston, Lamar University, and the USGS. The 

database includes incremental cumulative-rainfall values for 

1,659 runoff-producing storms that occurred during the period 

from 1959 to 1986 at or proximate to 91 USGS streamflowgaging stations located in small urban and rural watersheds in 

north and south central Texas (fig. 1). Descriptive information 

for the streamflow-gaging stations is given in supplement 1.

Rainfall-gaging stations (precipitation gages) represented 

in the database were located around the urban areas of Austin, 

Dallas, Fort Worth, and San Antonio, Tex., and in rural areas 

within the Brazos, Colorado, San Antonio, and Trinity River 

Basins. Storm durations ranged from a few hours to several 

days, and cumulative-rainfall amounts ranged from less than 

1 inch to more than 10 inches. These rainfall amounts were 

assumed to be representative of rainfall amounts across the 

drainage area of the coinciding streamflow-gaging station. 

Drainage areas for the 91 streamflow-gaging stations ranged 

from 0.26 to 166 square miles; however, drainage areas for 

72 of the stations were less than 20 square miles (supplement 1) 

(Asquith and others, 2004). For drainage areas that had more 

than one precipitation gage, an accumulated weighted-precipitation amount was derived from the multiple precipitation gages 
Previous Hyetograph Research 3

and was considered to be the best estimate of rainfall for 

that drainage area. The accumulated weighted-precipitation 

estimates were areal rainfall values rather than point rainfall 

values. For stations that had only one precipitation gage, the 

values were point values. The precipitation data used for this 

study are on file at the USGS office in Bismarck, N. Dak. 

Detailed discussions of the database used and locations of the 

precipitation gages are given in Asquith (2003), Asquith and 

others (2003), Asquith and Thompson (2003), and Asquith and 

others (2004).

Previous Hyetograph Research

Previous hyetograph research was conducted by Huff 

(1967, 1990), the Soil Conservation Service (1973), Pani and 

Haragan (1981), and Asquith (2003). Most of the following discussion was adapted from Asquith (2003).

Research by Huff

Huff (1990) presented dimensionless rainfall hyetographs 

as families of curves that were derived for storms classified as 

first, second, third, or fourth quartile. The storms were classified by Huff (1967) according to whether the greatest percentage of cumulative rainfall occurred in the first, second, third, or 

fourth quarter of the storm duration. Huff (1967) defined a 

“storm” as a “rain period separated from preceding and succeeding rainfall by 6 hours or more.” The database used by

Huff (1967) includes data for 261 storms that occurred over a 

400-square-mile network encompassing 49 recording rain 

gages in east-central Illinois. Data given in the database were 

collected between 1955 and 1966. All storms used had an areal 

mean rainfall of at least 0.5 inch and a duration of 3 to 48 hours. 

Also, at least one rain gage within the storm area had recorded 

at least 1 inch of rainfall during the storm duration.

In Huff (1967), the relative frequencies of the storms were 

30, 36, 19, and 15 percent for the first, second, third, and fourth 

quartiles, respectively. These frequencies were slightly different in Huff (1990) because the differences between point rainfall and areal rainfall were considered for that study. Huff 

(1990) concluded that first-quartile storms often had durations 

of less than 6 hours, second-quartile storms often had durations 

of 6 to 12 hours, third-quartile storms often had durations of 

12 to 24 hours, and fourth-quartile storms often had durations 

of more than 24 hours.

The median (50th-percentile) dimensionless hyetograph 

curves presented by Huff (1990) and shown in figure 2 were 

derived from point rainfall values (that is, rainfall data specifically for the recording device). The curves presented by Huff 

(1990) and shown in figure 3 were derived from areal rainfall 

values for areas that ranged from 10 to 50 square miles. Huff 

(1990) also provided curves that enveloped the median curve 

and represented other percentiles that ranged from 10 to 

90 percent. A comparison of the corresponding curves in 

figures 2 and 3 indicated the difference between the curves 

derived from point rainfall values and the curves derived from 

areal rainfall values generally was small. Huff (1990) concluded that the curves derived from point rainfall values also are 

Figure 2. Median (50th-percentile) dimensionless hyetograph curves derived from point rainfall values. (Modified from Huff, 1990.) PERCENT OF CUMULATIVE RAINFALL

PERCENT OF STORM DURATION

0

0 20 30 40 50 60 70 80 90 100 10

10

20

30

40

50

60

70

80

90

100

First-quartile storms

Second-quartile storms

Third-quartile storms

Fourth-quartile storms
4 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Figure 3. Median (50th-percentile) dimensionless hyetograph curves derived from areal rainfall values. (Rainfall values are for areas 

that ranged from 10 to 50 square miles.) (Modified from Huff, 1990.) 

PERCENT OF STORM DURATION

0 20 30 40 50 60 70 80 90 100 10

First-quartile storms

Second-quartile storms

Third-quartile storms

Fourth-quartile storms

PERCENT OF CUMULATIVE RAINFALL

0

10

20

30

40

50

60

70

80

90

100

valid for areas but that the validity of the curves diminishes as 

the area increases.

A discussion on the analysis of rainfall bursts and the 

effects of rainfall type, storm type, and storm shape and orientation on the distribution of rainfall with time is given in Huff 

(1967). Huff (1990) concluded that, for hydraulic design applications, first-quartile storm hyetographs should be used for time 

scales of about 6 hours or less, and second-quartile storm hyetographs should be used for time scales of about 6 to 12 hours. 

Third- and fourth-quartile storm hyetographs were not discussed for design applications.

Research by the Soil Conservation Service

The approach used by the Soil Conservation Service 

(1973), now the Natural Resources Conservation Service, provides dimensionless hyetograph curves classified into four 

types dependent upon specific regions. The Type II and III 

curves represent storms in Texas and elsewhere in the United 

States. The Type II curves are applicable for most of Texas and 

represent the most intense storms. The Type III curves are similar in shape to the Type II curves. The Type II and III curves 

shown in figure 4 indicate most rain would fall during the 

period that is between 45 and 55 percent of the storm duration.

Research by Pani and Haragan

The approach used by Pani and Haragan (1981) followed 

the approach used by Huff (1967), and results of the two studies 

were similar. Details of the approach used by Huff (1967) and 

clarification of the terminology used in this section are provided 

in the “Research by Huff” section of this report.

Pani and Haragan (1981) classified storms into four quartiles depending upon which quarter of dimensionless storm time 

had the greatest change in cumulative rainfall. Data were analyzed for 117 storms that occurred between May 15 and July 31 

for a 3-year period (1978–80). Data for the analysis were collected from a rain-gage network that was operated as part of the 

High Plains Cooperative Program (HIPLEX) (Texas Department of Water Resources, 1980). The rain-gage network was 

located near Big Spring in the southern High Plains of Texas 

and encompassed about 2,600 square miles (Pani and Haragan, 

1981). Data used in the analysis consisted of 15-minute rainfall 

values. The mid-May through July period was selected to 

confine the HIPLEX study to the period when convectivegenerated precipitation was most likely to occur. A storm was 

defined as a “rain period of at least 0.75-hour duration separated 

from preceding and succeeding rain periods by at least 1 hour” 

(Pani and Haragan, 1981).

In Pani and Haragan (1981), the relative frequencies of the 

storms were 13, 41, 32, and 14 percent for the first, second, 

third, and fourth quartiles, respectively. These frequencies indicate 73 percent of the storms were classified as second and third 

quartile. In Huff (1967, 1990), 66 percent of the storms were 

classified as first and second quartile. The chi-square goodnessof-fit test given in Davis (1986) and used in Pani and Haragan 

(1981) indicated significant differences in the relative frequencies for the two studies. Pani and Haragan (1981) stated that 

these differences could be attributed to advecting storm systems 
Approach 5

across a network that was six times larger in areal extent than 

the Illinois network used by Huff (1967, 1990). Pani and 

Haragan (1981, p. 78) concluded that “if a storm’s areal extent 

was larger than the network, which is often the case in Illinois, 

the resultant temporal distribution would show more rain falling 

during the early portion of the network lifetime and produce a 

classification in the first quartile.” Thus, as a network area 

increases, more storms will be characterized as central peaking. 

Huff (1967) reached a similar conclusion.

The conclusions reached by Huff (1967) and Pani and 

Haragan (1981) are relevant to the research presented in this 

report. The accumulated weighted-precipitation amounts given 

in the database for each storm were derived from one to as many 

as six rain gages and were assumed to be representative of rainfall amounts across drainage areas that ranged from 0.26 to 

166 square miles. Most drainage areas for this study were less 

than 20 square miles, and only two or three rain gages were in 

operation. Thus, the “network scale” in the database is very 

small in relation to the network scales used by Huff (1967, 

1990) and Pani and Haragan (1981).

The median (50th-percentile) dimensionless hyetograph 

curves shown in figure 5 for the southern High Plains of Texas 

were graphically extracted from figures given in Pani and 

Haragan (1981). Curves are shown for second- and thirdquartile storms. The chi-square test indicated no significant differences between the curves derived in Huff’s (1967) study and 

the curves derived in Pani and Haragan’s (1981) study. Thus, 

although the relative frequencies of the storms in Illinois were 

statistically different from the storms in Texas, the hyetograph 

curves were not statistically different. Hyetograph curves were 

not provided for first- and fourth-quartile storms because of 

small sample sizes for those quartiles (Pani and Haragan, 1981).

Because the rate of change in the cumulative-rainfall 

amount for third-quartile storms was greatest near 55 percent of 

the storm duration (fig. 5), Pani and Haragan (1981) concluded 

that second- and third-quartile storms were similar enough to be 

combined for design applications. The median (50th-percentile) 

composite dimensionless hyetograph curve for the combined 

storms is shown in figure 6 along with the 10th- and 90thpercentile composite curves for the southern High Plains of 

Texas. Pani and Haragan (1981) did not consider the effects of 

storm duration on the hyetograph curves.

Approach

For this study, the general approach given by Huff (1967, 

1990) was used to determine storm-quartile classifications from 

cumulative-rainfall values given in the database. The stormquartile classification depended upon when the heaviest rate of 

rainfall occurred during the storm duration. For example, the 

total storm duration was divided into quarters and then the 

change in rainfall during each quarter was determined. The 

quarter that had the greatest change was used as the quartile 

classification. The cumulative-rainfall values were divided into 

data groups on the basis of storm-quartile classification (first, 

second, third, fourth, and first through fourth combined), storm 

duration (0 to 6, 6 to12, 12 to 24, 24 to 72, and 0 to 72 hours), 

and rainfall amount (1 inch or more). Of the 1,659 runoffproducing storms for which data are available, 1,507 met the 

criteria for the storm duration (the number of hours passed) and 

Figure 4. Soil Conservation Service Type II and Type III hyetograph curves. (Modified from Asquith and Thompson, 2003.) 

Soil Conservation Service Type II

dimensionless hyetograph curve

Soil Conservation Service Type III

dimensionless hyetograph curve

PERCENT OF STORM DURATION

0 20 30 40 50 60 70 80 90 100 10

PERCENT OF CUMULATIVE RAINFALL

0

10

20

30

40

50

60

70

80

90

100
6 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Figure 5. Median (50th-percentile) dimensionless hyetograph curves for the southern High Plains of Texas. (Modified from Pani and 

Haragan, 1981.) 

Figure 6. Median (50th-percentile), 10th-, and 90th-percentile composite dimensionless hyetograph curves for the southern High Plains 

of Texas. (Modified from Pani and Haragan, 1981.) 

PERCENT OF STORM DURATION

0 20 30 40 50 60 70 80 90 100 10

Second-quartile storms

Third-quartile storms

PERCENT OF CUMULATIVE RAINFALL

0

10

20

30

40

50

60

70

80

90

100

10th-percentile

90th-percentile

Median (50th-percentile)

PERCENT OF STORM DURATION

0 20 30 40 50 60 70 80 90 100 10

PERCENT OF CUMULATIVE RAINFALL

0

10

20

30

40

50

60

70

80

90

100

the rainfall amount (the accumulated weighted-precipitation 

amount).

For some storms, the starting and ending times given in 

the database were not coincident with the starting and ending 

times of a substantial amount of rainfall that produced runoff. 

Some of the storms had long leading tails (the number of 

hours that passed before a measurable amount of rainfall 

occurred) that were an artifact of the method by which the 

original data were recorded and that give the numerical impression that a storm duration is longer than the actual storm 

duration. Thus, if more than 1 hour had passed before a 

measurable amount of rainfall occurred, the leading tails were 

removed by changing the HOURS_PASSED value in the 

hyetograph data file [see Asquith and others (2004) for specific 

details about the database]. For example, in the data file shown 
Empirical, Dimensionless, Cumulative-Rainfall Hyetographs 7

in figure 7, 21.5833 hours passed (HOURS_PASSED) before 

the first 0.35 inch of rainfall (ACCUM_WTD_PRECIP) was 

recorded. Thus, to remove the long leading tail, the zero 

HOURS_PASSED value shown in figure 7A was changed to 

the 21.5833 HOURS_PASSED value shown in figure 7B. 

Removal of the leading tail, in effect, shortened the storm duration, and, in some cases, affected the storm-quartile classification. Thus, the storm-quartile classifications were re-evaluated 

and a second group of data was generated. The original group 

of data is known as the untrimmed data group, and the second 

group of data is known as the trimmed data group.

After the storm-quartile classifications were re-evaluated, 

a double-tail 1-percent trimming was conducted to further 

reduce the length of both the leading and ending tails. The percentages of cumulative rainfall and storm duration then were 

recomputed. To accomplish the double-tail trimming, storms 

were considered to start after 1 percent or more of the cumulative-rainfall amount occurred and to stop after 99 percent of the 

cumulative-rainfall amount occurred.

After the double-tail 1-percent trimming was conducted, 

data for each cumulative-rainfall hyetograph were converted 

into data for a dimensionless hyetograph analysis. In dimensionless hyetographs, units of time and rainfall are expressed as 

percentages of the respective totals. Therefore, the time increments were converted to a percentage of storm duration, and the 

rainfall amounts were converted to a percentage of the cumulative-rainfall amount. The percentages of cumulative rainfall 

then were separated into bins and used to generate probability 

percentiles, averages, variances, standard deviations, and 

counts (number of samples) for each bin. The percentages were 

separated into bins by dividing the percentage of storm duration 

(the hours passed) into 2.5-percent intervals and by determining 

the percentage of cumulative rainfall that fell within each interval. The centers of the 2.5-percent intervals began at 2.5 percent 

and ended at 97.5 percent. Zero and 100 were included in the 

nearest respective increment. No interpolation, linear or otherwise, was used to determine in which bin the percentage of 

cumulative rainfall fell. For the example dimensionless hyetograph data given in table 1, the percentage of cumulative rainfall (the accumulated weighted-precipitation amount) for the 

2.5-percent bin (0 to 3.75 hours passed) is 6.522, the percentage 

for the 5-percent bin (3.75 to 6.25 hours passed) is 8.696, the 

percentage for the 7.5-percent bin (6.25 to 8.75 hours passed) is 

9.420, and the percentage for the 10-percent bin (8.75 to 

11.25 hours passed) is 11.59.

The number of percentages within each bin varied, and 

some bins had no values. Also, because the statistics for each 

bin varied, the dimensionless hyetograph curves that were 

developed from the data might not have been monotonically 

increasing. Therefore, to obtain the monotonically increasing 

curves desired for design applications, the data were adjusted 

using manual adjustments and a Friedman (1984) Supersmoothing program in the S-PLUS statistics package (release 3). 

Statistics for the untrimmed and trimmed data groups are given 

in supplements 2 through 5. The probability percentiles given in 

supplements 4 and 5 are the same as those given in supplements 

2 and 3, but the percentiles given in supplements 4 and 5 were 

smoothed to ensure monotonic increases.

Averages and ranges for the cumulative-rainfall amounts 

for the untrimmed and trimmed data groups are given in table 2. 

The distribution of storm occurrences for both groups is given 

in table 3. Removing the leading tails increased the firstquartile occurrences for all storm durations. The second- and 

third-quartile occurrences increased for storm durations of 0 to 

6 and 6 to 12 hours, and the fourth-quartile occurrences 

increased slightly for a storm duration of 0 to 6 hours. 

For a 12-hour or less trimmed storm duration, approximately 49 percent of the storms are first quartile. For trimmed 

storm durations of 12 to 24 and 24 to 72 hours, 47 and 

38 percent, respectively, of the storms are first quartile. These 

results are slightly different from those given by Pani and 

Haragan (1981) who classified most storms in Texas as second 

and third quartile. For a storm duration of 0 to 72 hours, the 

first-, second-, third-, and fourth-quartile storms in the trimmed 

data group accounted for 46, 21, 20, and 13 percent of all 

storms, respectively. 

The distributions of storm occurrences by storm duration 

and by storm-quartile classification are shown in figures 8 and 

9, respectively. The distributions were similar and typical of 

storm activity in the central part of Texas for all durations and 

for all quartile classifications. During the spring, convective 

storms are enhanced by frontal systems. During the fall, convective storms are enhanced by frontal and tropical systems. 

Dividing the hyetograph data groups into distinct spring and fall 

periods was not included in the scope of this study but might be 

helpful in further defining storm hyetographs. 

Empirical, Dimensionless, CumulativeRainfall Hyetographs

Probability percentiles allow the selection of a time distribution that is most appropriate for a particular application. In 

some cases, a median (50th-percentile) distribution of rainfall 

with time might be most useful, and, in other cases, 10th- to 

90th-percentile distributions of rainfall with time might be most 

useful. The median dimensionless hyetograph curves for firstthrough fourth-quartile storms and for the first- through fourthquartile storms combined are shown in figure 10 for a storm 

duration of 0 to 72 hours. The 10th- to 90th-percentile curves 

are shown in figure 11. The curves shown in the figures are 

for the trimmed and smoothed data group. Curves for the 

untrimmed data group were similar to curves for the trimmed 

data group. Smoothed median (50th-percentile) distributions of 

rainfall with time are given in table 4.
8 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Figure 7. Untrimmed (A) and trimmed (B) hyetograph data files. (Removal of the long leading tail was accomplished by changing the 

zero HOURS_PASSED value shown in bold to the 21.5833 HOURS_PASSED value shown in bold.) 

A (Untrimmed file)

# HYETOGRAPH FILE

# Filename=rain_sta08178300_1971_0613.dat

# SOURCE=ANNUAL COMP and ANALYSIS OF HYDRO DATA FOR URBAN STUDIES

# IN THE SAN ANT TX METRO AREA, 1971, PAGE 75,

# site=08178300 Alazan Creek at St. Cloud Street in San Antonio, Texas

# latitude=29()27'29"

# longitude=98()32'59"

# drainage area(mi2)=3.26

# DATE-TIME=date and time in Month/Day/Year@Hour:Minute

# THERE ARE TWO RAIN GAGES IN THE WATERSHED

# PRECIP1=RECORDED PRECIP IN INCHES FOR GAGE 1-A

# PRECIP2=RECORDED PRECIP IN INCHES FOR GAGE 2-A

# ACCUM_WTD_PRECIP RECORDED IN INCHES

DATE_TIME HOURS_PASSED PRECIP1 PRECIP2 ACCUM_WTD_PRECIP

06/13/1971@00:00:00 0.0000 0.0000 0.0000 0.0000

06/13/1971@21:35:00 21.5833 0.4000 0.2300 0.3500

06/13/1971@21:40:00 21.6667 0.5500 0.6100 0.5700

06/13/1971@21:45:00 21.7500 0.7000 0.7800 0.7200

06/13/1971@21:50:00 21.8333 0.8000 0.9000 0.8300

06/13/1971@21:55:00 21.9167 0.8100 0.9000 0.8300

06/13/1971@22:00:00 22.0000 0.8200 0.9000 0.8400

06/13/1971@22:05:00 22.0833 0.8200 0.9100 0.8400

06/13/1971@22:10:00 22.1667 0.8300 0.9100 0.8500

06/13/1971@22:15:00 22.2500 0.8300 0.9600 0.8700

06/13/1971@22:20:00 22.3333 0.8400 0.9700 0.8800

06/13/1971@22:25:00 22.4167 0.9400 0.9700 0.9500

B (Trimmed file)

# HYETOGRAPH FILE

# Filename=rain_sta08178300_1971_0613.dat

# SOURCE=ANNUAL COMP and ANALYSIS OF HYDRO DATA FOR URBAN STUDIES

# IN THE SAN ANT TX METRO AREA, 1971, PAGE 75,

# site=08178300 Alazan Creek at St. Cloud Street in San Antonio, Texas

# latitude=29()27'29"

# longitude=98()32'59"

# drainage area(mi2)=3.26

# DATE-TIME=date and time in Month/Day/Year@Hour:Minute

# THERE ARE TWO RAIN GAGES IN THE WATERSHED

# PRECIP1=RECORDED PRECIP IN INCHES FOR GAGE 1-A

# PRECIP2=RECORDED PRECIP IN INCHES FOR GAGE 2-A

# ACCUM_WTD_PRECIP RECORDED IN INCHES

DATE_TIME HOURS_PASSED PRECIP1 PRECIP2 ACCUM_WTD_PRECIP

06/13/1971@00:00:00 21.5833 0.0000 0.0000 0.0000

06/13/1971@21:35:00 21.5833 0.4000 0.2300 0.3500

06/13/1971@21:40:00 21.6667 0.5500 0.6100 0.5700

06/13/1971@21:45:00 21.7500 0.7000 0.7800 0.7200

06/13/1971@21:50:00 21.8333 0.8000 0.9000 0.8300

06/13/1971@21:55:00 21.9167 0.8100 0.9000 0.8300

06/13/1971@22:00:00 22.0000 0.8200 0.9000 0.8400

06/13/1971@22:05:00 22.0833 0.8200 0.9100 0.8400

06/13/1971@22:10:00 22.1667 0.8300 0.9100 0.8500

06/13/1971@22:15:00 22.2500 0.8300 0.9600 0.8700

06/13/1971@22:20:00 22.3333 0.8400 0.9700 0.8800

06/13/1971@22:25:00 22.4167 0.9400 0.9700 0.9500
Empirical, Dimensionless, Cumulative-Rainfall Hyetographs 9

Figure 8. Distribution of storm occurrences by storm duration. 

10

15

20

25

30

35

10

15

20

25

30

35

10

15

20

25

30

35

10

15

0

5

0

5

0

5

0

5

20

25

30

35

STORM OCCURRENCE, IN PERCENT

JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC

0 to 6 hours (untrimmed data group)

0 to 6 hours (trimmed data group)

6 to 12 hours (untrimmed data group)

6 to 12 hours (trimmed data group)

12 to 24 hours (untrimmed data group)

12 to 24 hours (trimmed data group)

24 to 72 hours (untrimmed data group)

24 to 72 hours (trimmed data group)

Selected percentiles for the first- and second-quartile 

storms are given in table 5. The 90th-percentile curve shown in 

figure 11 for first-quartile storms is typical of storms in which 

the rainfall occurs during a short period of time—that is, for 1 

of 10 first-quartile storms, about 91 percent of the rainfall 

occurs during the first quarter of the storm and about 98 percent 

of the rainfall occurs during the first half of the storm. The 50thpercentile curve indicates about 69 percent of the rainfall occurs 

during the first quarter of the storm and about 85 percent of the 

rainfall occurs during the first half of the storm. The 10thpercentile curve indicates about 39 percent of the rainfall occurs 

during the first quarter of the storm and about 58 percent of 

the rainfall occurs during the first half of the storm. The 90thpercentile curve for second-quartile storms indicates about 

69 percent of the rainfall occurs during the first quarter of the 

storm and about 89 percent of the rainfall occurs during the first 

half of the storm. The 50th-percentile curve indicates about 

28 percent of the rainfall occurs during the first quarter of the 
10 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Figure 9. Distribution of storm occurrences by storm-quartile classification. 

0

5

10

15

20

25

30

35

0

5

10

15

20

25

30

35

0

5

10

15

20

25

30

35

STORM OCCURRENCE, IN PERCENT

0

5

10

15

20

25

30

35

JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC

0

5

10

15

20

25

30

35

First-quartile storms

(untrimmed data group)

First-quartile storms

(trimmed data group)

Second-quartile storms

(untrimmed data group)

Second-quartile storms

(trimmed data group)

Third-quartile storms

(untrimmed data group)

Third-quartile storms

(trimmed data group)

Fourth-quartile storms

(untrimmed data group)

Fourth-quartile storms

(trimmed data group)

First- through fourth-quartile storms

combined

(untrimmed and trimmed data groups)
Empirical, Dimensionless, Cumulative-Rainfall Hyetographs 11

Figure 10. Median (50th-percentile) dimensionless hyetograph curves for a storm duration of 0 to 72 hours and a rainfall total of 1 inch or more. PERCENT OF CUMULATIVE RAINFALL

PERCENT OF STORM DURATION

Trimmed and smoothed data group

0

0 20 30 40 50 60 70 80 90 100 10

10

20

30

40

50

60

70

80

90

100

First-quartile storms

Second-quartile storms

Third-quartile storms

Fourth-quartile storms

First- through fourth-quartile storms combined

storm and about 65 percent of the rainfall occurs during the first 

half of the storm. The 10th-percentile curve indicates about 

6 percent of the rainfall occurs during the first quarter of the 

storm and about 39 percent of the rainfall occurs during the first 

half of the storm.

Selected percentiles for the third- and fourth-quartile 

storms are given in table 6. The 90th-percentile curve shown in 

figure 11 for third-quartile storms indicates about 39 percent of 

the rainfall occurs during the first quarter of the storm and about 

56 percent of the rainfall occurs during the first half of the 

storm. The 50th-percentile curve indicates about 19 percent of 

the rainfall occurs during the first quarter of the storm and about 

30 percent of the rainfall occurs during the first half of the 

storm. The 10th-percentile curve indicates about 4 percent of 

the rainfall occurs during the first quarter of the storm and about 

9 percent of the rainfall occurs during the first half of the storm. 

The 90th-percentile curve for fourth-quartile storms indicates 

about 39 percent of the rainfall occurs during the first quarter of 

the storm and about 50 percent of the rainfall occurs during the 

first half of the storm. The 50th-percentile curve indicates about 

19 percent of the rainfall occurs during the first quarter of the 

storm and about 34 percent of the rainfall occurs during the first 

half of the storm. The 10th-percentile curve indicates about 

5 percent of the rainfall occurs during the first quarter of the 

storm and about 12 percent of the rainfall occurs during the first 

half of the storm.

The hyetograph curves for the various percentiles indicate 

characteristics of certain storm types. For example, the 90thpercentile curve for first-quartile storms (fig. 11) indicates 

about 90 percent of the cumulative rainfall occurs during the 

first 20 percent of the storm duration. The 10th-percentile curve 

for first-quartile storms indicates about 30 percent of the cumulative rainfall occurs during the first 20 percent of the storm 

duration. The 90th-percentile curve for fourth-quartile storms 

indicates about 33 percent of the cumulative rainfall occurs 

during the first 20 percent of the storm duration. The 10thpercentile curve for fourth-quartile storms indicates less than 

5 percent of the cumulative rainfall occurs during the first 

20 percent of the storm duration. The 90th-percentile curves for 

the second- and third-quartile storms indicate about 67 and 
12 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Figure 11. 10th- to 90th-percentile dimensionless hyetograph curves for a storm duration of 0 to 72 hours and a rainfall total of 1 inch or

more. 

0 10 20 30 40 50 60 70 80 90 100

PERCENT OF STORM DURATION

0 10 20 30 40 50 60 70 80 90 100

PERCENT OF STORM DURATION

90th percentile

90th percentile

10th percentile

50th percentile

90th percentile

10th percentile

10th percentile

50th percentile

90th percentile

50th percentile

90th percentile

10th percentile

50th percentile

50th percentile

First-quartile storms

(trimmed and smoothed data group)

Third-quartile storms

(trimmed and smoothed data group)

Second-quartile storms

(trimmed and smoothed data group)

Fourth-quartile storms

(trimmed and smoothed data group)

0

10

20

30

40

50

60

70

80

90

100

0

10

20

30

40

50

60

70

80

90

100

0

10

20

30

40

50

60

70

80

90

100

PERCENT OF CUMULATIVE RAINFALL

First- through fourth-quartile

storms combined

(trimmed and smoothed data group)

10th percentile

33 percent, respectively, of the cumulative rainfall occurs 

during the first 20 percent of the storm duration. The 10thpercentile curves for the second- and third-quartile storms indicate about 5 and less than 1 percent, respectively, of the cumulative rainfall occurs during the first 20 percent of the storm 

duration.

The hyetograph curves and tables presented in this report 

were empirically derived and do not present exact mathematical 

relations. However, the curves and tables can be used to 

estimate distributions of rainfall with time for small drainage 

areas of less than about 160 square miles in urban and small 

rural watersheds in Texas.
Empirical, Dimensionless, Cumulative-Rainfall Hyetographs 13

Table 1. Example dimensionless hyetograph data.

[--, no value] 

Bin

(percent)

Hours passed

(percent)

Accumulated weightedprecipitation amount

(percent)

2.5 (0–3.75 hours passed) 0

1.888

0

6.522

5 (3.75–6.25 hours passed) 3.774 8.696

7.5 (6.25–8.75 hours passed) 7.548 9.420

10 (8.75–11.25 hours passed) 9.435 11.59

12.5 (11.25–13.75 hours passed) 13.21 14.49

15 (13.75–16.25 hours passed) 15.09 18.84

17.5 (16.25–18.75 hours passed) 16.98 20.29

20 (18.75–21.25 hours passed) 18.87

20.76

23.91

32.61

22.5 (21.25–23.75 hours passed) 22.64 38.41

25 (23.75–26.25 hours passed) 24.53 39.86

27.5 (26.25–28.75 hours passed) 26.42

28.30

43.48

53.62

30 (28.75–31.25 hours passed) 30.19 55.07

32.5 (31.25–33.75 hours passed) 32.08 57.97

35 (33.75–36.25 hours passed) 33.96

35.85

57.97

58.70

37.5 (36.25–38.75 hours passed) -- --

40 (38.75–41.25 hours passed) -- --

42.5 (41.25–43.75 hours passed) -- --

45 (43.75–46.25 hours passed) 45.28 62.32

47.5 (46.25–48.75 hours passed) -- --

50 (48.75–51.25 hours passed) 49.06 66.67

52.5 (51.25–53.75 hours passed) 52.83 68.84

55 (53.75–56.25 hours passed) 54.72 73.91

57.5 (56.25–58.75 hours passed) 58.49 78.26

60 (58.75–61.25 hours passed) -- --

62.5 (61.25–63.75 hours passed) 62.26 80.43

65 (63.75–66.25 hours passed) 64.15 86.23

67.5 (66.25–68.75 hours passed) -- --

70 (68.75–71.25 hours passed) -- --

72.5 (71.25–73.75 hours passed) 71.70 92.03

75 (73.75–76.25 hours passed) -- --

77.5 (76.25–78.75 hours passed) -- --

80 (78.75–81.25 hours passed) 81.13 95.65

82.5 (81.25–83.75 hours passed) -- --

85 (83.75–86.25 hours passed) -- --

87.5 (86.25–88.75 hours passed) -- --

90 (88.75–91.25 hours passed) -- --

92.5 (91.25–93.75 hours passed) -- --

95 (93.75–96.25 hours passed) -- --

97.5 (96.25–100.0 hours passed) 100.0 100.0
14 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Table 2. Averages and ranges for cumulative-rainfall amounts. 

Table 3. Distribution of storm occurrence

[Number in parenthesis is percent of total.] 

Storm duration

(hours)

Untrimmed data group Trimmed data group

Average rainfall

amount

(inches)

Range of

rainfall amount

(inches)

Average rainfall

amount

(inches)

Range of

rainfall amount

(inches)

First-quartile storms, untrimmed data group First-quartile storms, trimmed data group

0–6 1.99 1–5.76 1.97 1–5.76

6–12 2.56 1–10.95 2.51 1–10.95

12–24 3.02 1.07–9.35 2.98 1.07–9.35

24–72 3.25 1–8.44 3.25 1–8.44

0–72 2.68 1–10.95 2.67 1–10.95

Second-quartile storms, untrimmed data group Second-quartile storms, trimmed data group

0–6 1.83 1–3.55 1.82 1–3.55

6–12 2.60 1.01–4.36 2.61 1.01–5.04

12–24 3.17 1.17–6.99 3.23 1.07–7.26

24–72 3.68 1.34–8.45 3.82 1.41–8.45

0–72 2.86 1–8.45 2.83 1–8.45

Third-quartile storms, untrimmed data group Third-quartile storms, trimmed data group

0–6 1.77 1–3.68 1.80 1–3.68

6–12 2.27 1–5.47 2.32 1–5.47

12–24 2.47 1.07–4.90 2.66 1.18–4.90

24–72 3.68 1.05–8.89 3.95 1.39–8.89

0–72 2.79 1–8.89 2.84 1–8.89

Fourth-quartile storms, untrimmed data group Fourth-quartile storms, trimmed data group

0–6 1.71 1.03–2.93 1.68 1.03–2.93

6–12 1.97 1.02–3.97 2.02 1.02–3.97

12–24 2.31 1.06–5.42 2.34 1.06–5.42

24–72 3.88 1.02–19.26 4.57 1.56–19.26

0–72 2.75 1.02–19.26 2.82 1.02–19.26

Stormquartile

classification

Storm duration (hours)

0 to 6 6 to 12 12 to 24 24 to 72 0 to 72

Untrimmed

data group

Trimmed

data group

Untrimmed

data group

Trimmed

data group

Untrimmed

data group

Trimmed

data group

Untrimmed

data group

Trimmed

data group

Untrimmed

data group

Trimmed

data group

First 157.(51) 173.(51) 136.(44) 161.(47) 187.(39) 220.(47) 102.(25) 135.(38) 582.(39) 689.(46)

Second 90.(29) 96.(29) 50.(16) 62.(18) 106.(22) 91.(19) 90.(22) 75.(21) 336.(22) 324.(21)

Third 47.(15) 50.(15) 70.(23) 74.(21) 102.(21) 78.(17) 133.(33) 95.(26) 352.(23) 297.(20)

Fourth 15.(5) 17.(5) 53.(17) 47.(14) 85.(18) 79.(17) 84.(20) 54.(15) 237.(16) 197.(13)

All 309.(100) 336.(100) 309.(100) 344.(100) 480.(100) 468.(100) 409.(100) 359.(100) 1,507.(100) 1,507.(100)
Empirical, Dimensionless, Cumulative-Rainfall Hyetographs 15

Table 4. Smoothed median (50th-percentile) distributions of rainfall with time for a storm duration of 0 to 72 hours and a rainfall total

of 1 inch or more 

Center of

percent-of-stormduration interval

Median (50th-percentile)

First-quartile

storms

(percent)

Second-quartile

storms

(percent)

Third-quartile

storms

(percent)

Fourth-quartile

storms

(percent)

First- through

fourth-quartile

storms

(percent)

2.5 8.70 2.81 2.51 3.28 6.37

5.0 18.81 5.89 4.73 5.16 13.58

7.5 28.27 8.89 6.86 7.53 20.49

10.0 36.71 11.82 8.96 9.59 26.83

12.5 43.93 14.60 10.92 11.30 32.42

15.0 50.35 17.32 12.76 12.93 37.21

17.5 55.74 19.93 14.41 14.30 41.00

20.0 60.57 22.61 15.95 15.98 44.11

22.5 64.85 25.34 17.34 17.64 46.55

25.0 68.65 28.36 18.66 19.46 48.54

27.5 71.70 31.47 19.91 21.27 50.23

30.0 74.09 34.77 21.05 23.10 51.68

32.5 75.85 38.14 22.08 24.71 52.90

35.0 77.23 41.69 22.89 26.30 54.27

37.5 78.42 45.34 23.45 27.67 55.49

40.0 79.62 49.29 23.77 28.95 56.80

42.5 80.86 53.27 24.24 30.19 58.03

45.0 82.20 57.39 25.14 31.51 59.31

47.5 83.43 61.42 27.11 32.86 60.49

50.0 84.59 65.46 30.15 34.27 61.97

52.5 85.59 69.27 34.37 35.65 63.51

55.0 86.42 73.09 39.28 36.92 65.39

57.5 87.12 76.77 44.53 38.02 67.56

60.0 87.75 80.35 49.48 39.04 69.85

62.5 88.28 83.34 54.35 39.90 72.11

65.0 88.85 85.85 58.90 40.72 74.32

67.5 89.46 87.80 63.36 41.71 76.38

70.0 90.10 89.24 67.56 43.15 78.21

72.5 90.81 90.23 71.75 45.03 80.00

75.0 91.53 91.15 75.58 47.52 81.61

77.5 92.22 92.03 79.15 50.60 83.25

80.0 92.87 92.90 82.29 54.45 84.84

82.5 93.54 93.81 85.28 59.01 86.54

85.0 94.25 94.75 87.93 64.24 88.30

87.5 95.01 95.69 90.36 70.27 90.21

90.0 95.84 96.66 92.62 76.81 92.18

92.5 96.82 97.64 94.86 83.44 94.22

95.0 97.90 98.63 97.15 90.01 96.21

97.5 99.02 99.65 98.94 96.48 98.21
16 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Table 5. Selected percentiles for first- and second-quartile storms for a storm duration of 0 to 72 hours and a rainfall total of 1 inch or 

more.

Center of

percent-of-stormduration interval

First-quartile storms Second-quartile storms

10th percentile 50th percentile 90th percentile 10th percentile 50th percentile 90th percentile

2.5 1.93 8.70 26.06 0.12 2.81 15.86

5.0 6.12 18.81 42.85 .89 5.89 30.59

7.5 10.29 28.27 57.39 1.63 8.89 43.53

10.0 14.60 36.71 69.27 2.25 11.82 53.80

12.5 18.93 43.93 78.01 2.81 14.60 61.15

15.0 23.41 50.35 83.56 3.37 17.32 65.51

17.5 27.83 55.74 86.94 3.80 19.93 67.30

20.0 32.04 60.57 89.19 4.27 22.61 68.04

22.5 35.78 64.85 90.49 4.86 25.34 68.63

25.0 39.17 68.65 91.40 5.65 28.36 69.42

27.5 41.95 71.70 92.31 6.63 31.47 70.71

30.0 44.31 74.09 93.25 8.01 34.77 72.44

32.5 46.54 75.85 94.14 9.86 38.14 74.41

35.0 48.69 77.23 95.12 12.27 41.69 76.69

37.5 50.63 78.42 95.96 15.34 45.34 79.03

40.0 52.50 79.62 96.65 19.26 49.29 81.40

42.5 54.19 80.86 97.20 23.91 53.27 83.69

45.0 55.64 82.20 97.64 28.91 57.39 85.88

47.5 56.81 83.43 97.93 34.16 61.42 87.66

50.0 57.89 84.59 98.18 39.48 65.46 89.26

52.5 58.78 85.59 98.40 44.37 69.27 90.80

55.0 59.59 86.42 98.59 48.94 73.09 92.35

57.5 60.30 87.12 98.77 53.18 76.77 93.84

60.0 60.92 87.75 98.94 56.77 80.35 95.30

62.5 61.43 88.28 99.08 59.46 83.34 96.51

65.0 61.97 88.85 99.20 61.64 85.85 97.43

67.5 62.39 89.46 99.31 63.07 87.80 98.04

70.0 62.92 90.10 99.38 63.99 89.24 98.41

72.5 63.62 90.81 99.43 64.97 90.23 98.61

75.0 64.64 91.53 99.47 66.23 91.15 98.77

77.5 66.09 92.22 99.49 67.72 92.03 98.91

80.0 68.05 92.87 99.51 69.70 92.90 99.06

82.5 70.36 93.54 99.52 72.19 93.81 99.22

85.0 73.14 94.25 99.55 74.73 94.75 99.39

87.5 76.44 95.01 99.59 77.60 95.69 99.56

90.0 80.08 95.84 99.64 80.89 96.66 99.70

92.5 84.23 96.82 99.71 84.74 97.64 99.82

95.0 88.89 97.90 99.81 89.04 98.63 99.92

97.5 93.81 99.02 99.90 93.87 99.65 100.00
Empirical, Dimensionless, Cumulative-Rainfall Hyetographs 17

Table 6. Selected percentiles for third- and fourth-quartile storms for a storm duration of 0 to 72 hours and a rainfall total of 1 inch or 

more.

Center of

percent-of-stormduration interval

Third-quartile storms Fourth-quartile storms

10th percentile 50th percentile 90th percentile 10th percentile 50th percentile 90th percentile

2.5 0.45 2.51 8.13 0.43 3.28 11.93

5.0 .96 4.73 13.25 .92 5.16 18.53

7.5 1.42 6.86 17.94 1.37 7.53 24.03

10.0 1.81 8.96 22.26 1.75 9.59 28.07

12.5 2.21 10.92 26.05 2.04 11.30 30.76

15.0 2.59 12.76 29.37 2.51 12.93 32.60

17.5 2.91 14.41 32.21 2.95 14.30 34.08

20.0 3.22 15.95 34.87 3.55 15.98 35.70

22.5 3.56 17.34 37.16 4.18 17.64 37.55

25.0 3.80 18.66 39.21 5.00 19.46 39.43

27.5 4.08 19.91 41.07 5.71 21.27 41.14

30.0 4.32 21.05 42.74 6.48 23.10 42.66

32.5 4.61 22.08 44.15 7.16 24.71 43.85

35.0 4.82 22.89 45.40 7.86 26.30 44.73

37.5 5.12 23.45 46.48 8.45 27.67 45.45

40.0 5.39 23.77 47.38 8.99 28.95 46.11

42.5 5.84 24.24 48.28 9.58 30.19 46.79

45.0 6.48 25.14 49.80 10.25 31.51 47.54

47.5 7.51 27.11 52.46 11.03 32.86 48.52

50.0 8.84 30.15 56.44 11.73 34.27 49.60

52.5 10.53 34.37 61.64 12.44 35.65 50.83

55.0 12.45 39.28 67.86 12.95 36.92 52.17

57.5 14.51 44.53 74.03 13.45 38.02 53.56

60.0 16.71 49.48 79.32 13.76 39.04 54.83

62.5 19.05 54.35 83.56 14.04 39.90 56.11

65.0 21.52 58.90 86.82 14.42 40.72 57.25

67.5 24.30 63.36 89.28 15.66 41.71 58.66

70.0 27.37 67.56 91.37 17.04 43.15 60.39

72.5 30.78 71.75 93.22 19.05 45.03 62.82

75.0 34.87 75.58 94.79 21.42 47.52 66.21

77.5 39.77 79.15 96.02 24.00 50.60 70.65

80.0 45.21 82.29 96.91 26.18 54.45 75.41

82.5 51.52 85.28 97.51 28.99 59.01 80.60

85.0 58.42 87.93 97.99 32.14 64.24 85.60

87.5 65.64 90.36 98.44 36.96 70.27 89.88

90.0 72.88 92.62 98.86 44.05 76.81 93.26

92.5 80.35 94.86 99.23 53.75 83.44 95.95

95.0 87.52 97.15 99.55 65.55 90.01 97.86

97.5 94.68 98.94 99.85 79.24 96.48 99.34
18 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Summary

A database of incremental cumulative-rainfall values for 

1,659 runoff-producing storms that occurred during the period 

from 1959 to 1986 at or proximate to 91 U.S. Geological Survey 

streamflow-gaging stations located in small urban and rural 

watersheds in north and south central Texas was used to 

develop empirical, dimensionless, cumulative-rainfall hyetographs. Storm durations ranged from a few hours to several 

days, and cumulative-rainfall amounts ranged from less than 

1 inch to more than 10 inches. Drainage areas for the 91 streamflow-gaging stations ranged from 0.26 to 166 square miles; 

however, drainage areas for 72 of the stations were less than 

20 square miles.

Storm-quartile classifications were determined from the 

cumulative-rainfall values, which were divided into data groups 

on the basis of storm-quartile classification (first, second, third, 

fourth, and first through fourth combined), storm duration (0 to 

6, 6 to 12, 12 to 24, 24 to 72, and 0 to 72 hours), and rainfall 

amount (1 inch or more). The storm-quartile classification 

depended upon when the heaviest rate of rainfall occurred during the storm duration. Removal of long leading tails, in effect, 

shortened the storm duration, and, in some cases, affected the 

storm-quartile classification. Therefore, two storm groups, 

untrimmed and trimmed, were used for analysis. The trimmed 

storms generally are preferred for interpretation. For a 12-hour 

or less trimmed storm duration, approximately 49 percent of 

the storms are first quartile. For trimmed storm durations of 

12 to 24 and 24 to 72 hours, 47 and 38 percent, respectively, 

of the storms are first quartile. For a trimmed storm duration of 

0 to 72 hours, the first-, second-, third-, and fourth-quartile 

storms accounted for 46, 21, 20, and 13 percent of all storms, 

respectively.

The 90th-percentile curve for first-quartile storms indicated about 90 percent of the cumulative rainfall occurs during

the first 20 percent of the storm duration. The 10th-percentile 

curve for first-quartile storms indicated about 30 percent of the 

cumulative rainfall occurs during the first 20 percent of the 

storm duration. The 90th-percentile curve for fourth-quartile 

storms indicated about 33 percent of the cumulative rainfall 

occurs during the first 20 percent of the storm duration. The 

10th-percentile curve for fourth-quartile storms indicated less 

than 5 percent of the cumulative rainfall occurs during the first 

20 percent of the storm duration.

Statistics for the empirical, dimensionless, cumulativerainfall hyetographs are presented in the report along with hyetograph curves and tables. The hyetograph curves and tables 

presented do not present exact mathematical relations but can 

be used to estimate distributions of rainfall with time for small 

drainage areas of less than about 160 square miles in urban and 

small rural watersheds in Texas.

Acknowledgments

The authors recognize the contributions of Amy 

Ronnfeldt, Design Division (Austin), Project Director 0–4194, 

and David Stolpa, Design Division (Austin), Program Coordinator for Project 0–4194.

References

Asquith, W.H., 2003, Modeling of runoff-producing rainfall 

hyetographs in Texas using L-moment statistics: Austin, 

Texas, University of Texas, Ph.D. dissertation, 386 p.

Asquith, W.H., Bumgarner, J.R., and Fahlquist, L.S., 2003, A 

triangular model of dimensionless runoff producing rainfall 

hyetographs in Texas: Journal of the American Water 

Resources Association, v. 39, no. 4, p. 911–921.

Asquith, W.H., and Thompson, D.B., 2003, Modeling of 

runoff-producing rainfall hyetographs in Texas using 

L-moments: Corpus Christi, Texas, American Society of 

Civil Engineers, Texas Section, Spring 2003 Meeting, 23 p.

Asquith, W.H., Thompson, D.B., Cleveland, T.G., and Fang, 

Xing, 2004, Synthesis of rainfall and runoff data used for 

Texas Department of Transportation Research Projects

0–4193 and 0–4194: U.S. Geological Survey Open-File 

Report 2004–1034, 1,050 p.

Chow, V.T., Maidment, D.R., and Mays, L.W., 1988, Applied 

hydrology: New York, McGraw-Hill Publishing Company, 

572 p.

Davis, J.C., 1986, Statistics and data analysis in geology: New 

York, John Wiley and Sons, Inc., 646 p.

Friedman, J.H., 1984, A variable span smoother: Stanford, 

California, Laboratory for Computational Statistics, Department of Statistics, Stanford University, Technical Report 

LCS 5, accessed July 2003 at URL

http://www-stat.stanford.edu/~jhf/

Haan, C.T., Barfield, B.J., and Hayes, J.C., 1994, Design 

hydrology and sedimentology for small catchments: San 

Diego, California, Academic Press, 588 p.

Huff, F.A., 1967, Time distribution of rainfall in heavy storms: 

Water Resources Research, v. 3, no. 4, p. 1,007–1,019.

Huff, F.A., 1990, Time distributions of heavy rainstorms in 

Illinois: Champaign, Illinois, Illinois State Water Survey 

Circular 173, 18 p.

Pani, E.A., and Haragan, D.R., 1981, A comparison of Texas 

and Illinois temporal rainfall distributions: Fourth Conference on Hydrometeorology, American Meteorological 

Society, p. 76–80.

Soil Conservation Service, 1973, A method for estimating 

volume and rate of runoff in small watersheds: Washington, 

D.C., U.S. Department of Agriculture, Soil Conservation 

Service, SCS–TP–149, 19 p.

Texas Department of Water Resources, 1980, HIPLEX 1980 

operations plan, Big Spring, Texas: Austin, Texas, LP–125, 

47 p.
Supplements 1–5
Supplement 1 21

Supplement 1. Descriptive information for streamflow-gaging stations represented in hyetograph database.

[Data from Asquith, 2003; SH, State highway; FM, farm to market road; IH, Interstate highway; Sub., subwatershed]

Station

number Station name Latitude Longitude

Drainage

area

(square miles)

Approximate

period of

precipitation

record

Number of

storms

Austin (austin) database

08154700 Bull Creek at Loop 360, Austin, Texas 30°22'19" 97°47'04" 22.3 1978–86 14

08155200 Barton Creek at SH 71, Oak Hill, Texas 30°17'46" 97°55'31" 89.7 1978–82 6

08155300 Barton Creek at Loop 360, Austin, Texas 30°14'40" 97°48'07" 116 1979–86 8

08155550 West Bouldin Creek at Riverside Drive,

Austin, Texas

30°15'49" 97°45'17" 3.12 1977–85 10

08156650 Shoal Creek at Steck Avenue, Austin,

Texas

30°21'55" 97°44'11" 2.79 1975–82 13

08156700 Shoal Creek at Northwest Park, Austin,

Texas

30°20'50" 97°44'41" 7.03 1976–83 17

08156750 Shoal Creek at White Rock Drive, Austin,

Texas

30°20'21" 97°44'50" 7.56 1976–80 14

08156800 Shoal Creek at 12th Street, Austin, Texas 30°16'35" 97°45'00" 12.3 1975–86 24

08157000 Waller Creek at 38th Street, Austin, Texas 30°17'49" 97°43'36" 2.31 1967–80 41

08157500 Waller Creek at 23rd Street, Austin, Texas 30°17'08" 97°44'01" 4.13 1967–80 40

08158050 Boggy Creek at U.S. 183, Austin, Texas 30°15'47" 97°40'20" 13.1 1976–85 10

08158100 Walnut Creek at FM 1325, Austin, Texas 30°24'35" 97°42'41" 12.6 1976–86 15

08158200 Walnut Creek at Dessau Road, Austin,

Texas

30°22'30" 97°39'37" 26.2 1976–86 17

08158380 Little Walnut Creek at Georgian Drive,

Austin, Texas

30°21'15" 97°41'52" 5.22 1985–86 2

08158400 Little Walnut Creek at IH 35, Austin, Texas 30°20'57" 97°41'34" 5.57 1976–81 10

08158500 Little Walnut Creek at Manor Road, Austin,

Texas

30°18'34" 97°40'04" 12.1 1976–81 15

08158600 Walnut Creek at Webberville Road, Austin,

Texas

30°16'59" 97°39'17" 51.3 1974–86 21

08158700 Onion Creek near Driftwood, Texas 30°04'59" 98°00'29" 124 1980–87 6

08158800 Onion Creek at Buda, Texas 30°05'09" 97°50'52" 166 1980–83 2

08158810 Bear Creek below FM 1826, Driftwood,

Texas

30°09'19" 97°56'23" 12.2 1980–86 8

08158820 Bear Creek at FM 1626, Manchaca, Texas 30°08'25" 97°50'50" 24.0 1980–83 2

08158825 Little Bear Creek at FM 1626, Manchaca,

Texas

30°07'31" 97°51'43" 21.0 1980–83 2
22 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

Austin (austin) database—Continued

08158840 Slaughter Creek at FM 1826, Austin, Texas 30°12'32" 97°54'11" 8.24 1979–86 11

08158860 Slaughter Creek at FM 2304, Austin, Texas 30°09'43" 97°49'55" 23.1 1981–82 2

08158880 Boggy Creek (south) at Circle “S" Road,

Austin, Texas

30°10'50" 97°46'55" 3.58 1976–86 14

08158920 Williamson Creek at Oak Hill, Texas 30°14'06" 97°51'36" 6.3 1979–84 14

08158930 Williamson Creek at Manchaca Road,

Austin, Texas

30°13'16" 97°47'36" 19.0 1976–84 18

08158970 Williamson Creek at Jimmy Clay Road,

Austin, Texas

30°11'21" 97°43'56" 27.6 1976–86 16

08159150 Wilbarger Creek near Pflugerville, Texas 30°27'16" 97°36'02" 4.61 1967–77 29

Dallas (dallas) database

08055580 Joes Creek at Royal Lane, Dallas, Texas 32°53'43" 96°41'36" 1.94 1974–79 7

08055600 Joes Creek, Dallas, Texas 32°51'41" 96°52'27" 7.51 1973–79 10

08055700 Bachman Branch, Dallas, Texas 32°51'37" 96°50'13" 10.0 1964–79 41

08056500 Turtle Creek, Dallas, Texas 32°48'26" 96°48'08" 7.98 1964–79 42

08057020 Coombs Creek at Sylvan Avenue, Dallas,

Texas

32°46'01" 96°50'07" 4.75 1965–79 7

08057050 Cedar Creek at Bonnie View Road, Dallas,

Texas

32°44'50" 96°47'44" 9.42 1974–79 3

08057120 Spanky Branch at McCallum Lane, Dallas,

Texas

32°57'58" 96°48'11" 6.77 1973–78 5

08057130 Rush Branch at Arapaho Road, Dallas, Texas 32°57'45" 96°47'44" 1.22 1973–79 7

08057140 Cottonwood Creek at Forest Lane, Dallas,

Texas

32°54'33" 96°45'54" 8.5 1973–78 6

08057160 Floyd Branch at Forest Lane, Dallas, Texas 32°54'33" 96°45'34" 4.17 1974–79 8

08057320 Ash Creek at Highland Road, Dallas, Texas 32°48'18" 96°43'04" 6.92 1973–78 5

08057415 Elam Creek at Seco Boulevard, Dallas,

Texas

32°44'14" 96°41'36" 1.25 1973–79 8

08057418 Fivemile Creek at Kiest Boulevard, Dallas,

Texas

32°42'19" 96°51'32" 7.65 1976–79 7

08057420 Fivemile Creek at U.S. 77, Dallas, Texas 32°41'15" 96°49'22" 13.2 1973–79 10

08057425 Woody Branch at U.S. 77, Dallas, Texas 32°40'58" 96°49'22" 11.5 1973–79 10

Supplement 1. Descriptive information for streamflow-gaging stations represented in hyetograph database.—Continued

[Data from Asquith, 2003; SH, State highway; FM, farm to market road; IH, Interstate highway; Sub., subwatershed]

Station

number Station name Latitude Longitude

Drainage

area

(square miles)

Approximate

period of

precipitation

record

Number of

storms
Supplement 1 23

Dallas (dallas) database—Continued

08057435 Newton Creek at IH 635, Dallas, Texas 32°39'19" 96°44'41" 5.91 1976–79 4

08057440 Whites Branch at IH 635, Dallas, Texas 32°39'26" 96°44'25" 2.53 1976–79 4

08057445 Prairie Creek at U.S. 175, Dallas, Texas 32°42'17" 96°40'11" 9.03 1976–79 8

08061620 Duck Creek at Buckingham Road, Garland,

Texas

32°55'53" 96°39'55" 8.05 1973–79 8

08061920 South Mesquite Creek at SH 352, Mesquite,

Texas

32°46'09" 96°37'18" 13.4 1973–79 9

08061950 South Mesquite Creek at Mercury Road,

Mesquite, Texas

32°43'32" 96°34'12" 23.0 1969–79 31

Fort Worth (fortworth) database

-- Seminary South Shopping Center and associated

drainage area, Fort Worth, Texas

-- -- .38 1970–76 21

08048520 Sycamore Creek at IH 35–W, Fort Worth,

Texas

32°39'55" 97°19'16" 17.7 1970–77 24

08048530 Sycamore Creek tributary above Seminary

South Shopping Center, Fort Worth, Texas

32°41'08" 97°19'44" .97 1970–77 28

08048540 Sycamore Creek tributary at IH 35–W, Fort

Worth, Texas

32°41'18" 97°19'11" 1.35 1970–76 24

08048550 Dry Branch at Blandin Street, Fort Worth,

Texas

32°47'19" 97°18'22" 1.08 1969–76 25

08048600 Dry Branch at Fain Street, Fort Worth, Texas 32°46'34" 97°17'18" 2.15 1969–77 27

08048820 Little Fossil Creek at IH 820, Fort Worth,

Texas

32°50'22" 97°19'22" 5.64 1969–77 20

08048850 Little Fossil Creek at Mesquite Street, Fort

Worth, Texas

32°48'33" 97°17'28" 12.3 1969–77 25

San Antonio (sanantonio) database

08177600 Olmos Creek tributary at FM 1535, Shavano

Park, Texas

29°34'35" 98°32'45" .33 1970–81 14

08177700 Olmos Creek at Dresden Drive, San

Antonio, Texas

29°29'56" 98°30'36" 21.2 1969–78 23

08178300 Alazan Creek at St. Cloud Street, San

Antonio, Texas

29°27'29" 98°32'59" 3.26 1969–79 30

08178555 Harlendale Creek at West Harding Street,

San Antonio, Texas

29°21'05" 98°29'32" 2.43 1977–80 10

Supplement 1. Descriptive information for streamflow-gaging stations represented in hyetograph database.—Continued

[Data from Asquith, 2003; SH, State highway; FM, farm to market road; IH, Interstate highway; Sub., subwatershed]

Station

number Station name Latitude Longitude

Drainage

area

(square miles)

Approximate

period of

precipitation

record

Number of

storms
24 Empirical, Dimensionless, Cumulative-Rainfall Hyetographs for Selected Small Watersheds in Texas

San Antonio (sanantonio) database—Continued

08178600 Panther Springs Creek at FM 2696 near San

Antonio, Texas

29°37'31" 98°31'06" 9.54 1969–75 13

08178620 Lorence Creek at Thousand Oaks Boulevard,

San Antonio, Texas

29°35'24" 98°27'47" 4.05 1981–81 3

08178640 West Elm Creek at San Antonio, Texas 29°37'23" 98°26'29" 2.45 1976–79 8

08178645 East Elm Creek at San Antonio, Texas 29°37'04" 98°25'41" 2.33 1976–79 6

08178690 Salado Creek tributary at Bitters Road, San

Antonio, Texas

29°31'36" 98°26'25" .26 1969–81 41

08178736 Salado Creek tributary at Bee Street, San

Antonio, Texas

29°26'38" 98°27'13" .45 1972–76 12

08181000 Leon Creek tributary at FM 1604, San Antonio,

Texas

29°35'14" 98°37'40" 5.57 1970–79 10

08181400 Helotes Creek at Helotes, Texas 29°34'42" 98°41'29" 15.0 1969–81 15

08181450 Leon Creek tributary at Kelly Air Force Base,

Texas

29°23'12" 98°36'00" 1.19 1969–79 30

Small rural watersheds (smallruralsheds) database

08042650 North Creek Sub. 28A near Jermyn, Texas 33°14'52" 98°19'19" 6.82 1973–79 14

08042700 North Creek near Jacksboro, Texas 33°16'57" 98°17'53" 21.6 1959–79 58

08050200 Elm Fork Sub. 6 near Muenster, Texas 33°37'13" 97°24'15" .77 1961–70 34

08052630 Little Elm Creek Sub. 10 near Gunter, Texas 33°24'33" 96°48'41" 2.10 1966–76 29

08052700 Little Elm Creek near Aubrey, Texas 33°17'00" 96°53'33" 75.5 1959–76 58

08057500 Honey Creek Sub. 11 near McKinney, Texas 33°18'12" 96°41'22" 2.14 1960–70 32

08058000 Honey Creek Sub. 12 near McKinney, Texas 33°18'20" 96°40'12" 1.26 1959–70 29

08063200 Pin Oak Creek near Hubbard, Texas 31°48'01" 96°43'02" 17.6 1959–71 33

08094000 Green Creek Sub. 1 near Dublin, Texas 32°10'00" 98°20'30" 13.18/4.19 1959–71 29

08096800 Cow Bayou Sub. 4 near Bruceville, Texas 31°19'59" 97°16'02" 15.25/5.04 1959–75 51

08098300 Little Pond Creek near Burlington, Texas 31°01'35" 96°59'17" 22.2 1964–72 19

08108200 North Elm Creek near Cameron, Texas 30°55'52" 97°01'13" 48.6 1964–72 21

08136900 Mukewater Creek Sub. 10A near Trickham,

Texas

31°39'01" 99°13'30" 21.8 1966–73 22

Supplement 1. Descriptive information for streamflow-gaging stations represented in hyetograph database.—Continued

[Data from Asquith, 2003; SH, State highway; FM, farm to market road; IH, Interstate highway; Sub., subwatershed]

Station

number Station name Latitude Longitude

Drainage

area

(square miles)

Approximate

period of

precipitation

record

Number of

storms
Supplement 1 25

Small rural watersheds (smallruralsheds) database—Continued

08137000 Mukewater Creek Sub. 9 near Trickham,

Texas

31°41'40" 99°12'18" 4.02 1961–73 38

08137500 Mukewater Creek at Trickham, Texas 31°35'24" 99°13'36" 70.4 1959–61 5

08139000 Deep Creek Sub. 3 near Placid, Texas 31°17'25" 99°09'22" 3.42 1960–71 29

08140000 Deep Creek Sub. 8 near Mercury, Texas 31°24'08" 99°07'17" 14.32/5.41 1960–71 30

08182400 Calaveras Creek Sub. 6 near Elmendorf, Texas 29°22'49" 98°17'33" 7.01 1961–71 25

08187000 Escondido Creek Sub. 1 near Kenedy, Texas 28°46'41" 97°53'41" 3.29 1959–71 32

08187900 Escondido Creek Sub. 11 near Kenedy, Texas 28°51'39" 97°50'39" 8.43 1962–70 21

1Both drainage areas have been published for this station.

Supplement 1. Descriptive information for streamflow-gaging stations represented in hyetograph database.—Continued

[Data from Asquith, 2003; SH, State highway; FM, farm to market road; IH, Interstate highway; Sub., subwatershed]

Station

number Station name Latitude Longitude

Drainage

area

(square miles)

Approximate

period of

precipitation

record

Number of

storms
Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86. [The interval is the center of the percent-of-storm-duration interval; --, no data] Interval Percentile Average (percent) Variance (percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th First-quartile storms; storm duration 0 to 6 hours 2.5 0 0 0 0 0 0 0 0 0 3.57 7.75 2.43 42.52 

5.0 4.06 6.46 8.75 9.58 13.29 17.98 19.81 22.42 25.04 28.35 37.91 18.61 162.10 7.5 4.79 9.65 11.01 13.79 16.23 18.11 24.63 31.44 34.68 37.00 48.09 23.42 255.77 

10.0 11.58 19.16 21.31 23.28 27.97 32.89 37.03 45.12 46.74 50.00 58.99 34.47 307.38 12.5 14.49 22.60 27.19 29.31 34.35 36.22 39.34 49.15 53.74 59.80 64.29 39.41 372.42 15.0 18.89 30.17 31.87 34.77 37.79 41.27 48.74 53.90 59.69 61.86 72.60 44.73 388.65 17.5 19.65 33.13 38.87 41.37 47.83 54.33 60.92 66.42 68.97 71.79 77.39 52.33 429.78 20.0 32.61 45.81 50.13 51.97 59.06 63.37 67.23 71.55 75.09 78.95 83.90 61.02 365.99 22.5 36.13 45.91 51.92 57.41 62.03 67.72 75.25 78.29 81.48 84.39 90.81 65.72 392.25 25.0 36.92 44.37 49.28 53.14 61.09 67.86 75.90 79.45 81.60 83.01 89.28 65.00 422.48 27.5 47.00 53.79 57.83 59.78 64.02 68.21 72.92 78.95 79.71 82.36 88.29 67.76 261.11 30.0 52.55 60.27 62.58 64.56 73.80 76.47 83.77 85.37 85.86 86.44 91.45 74.39 219.16 32.5 45.27 55.23 59.29 66.51 71.53 77.60 82.28 84.31 85.85 87.29 90.18 71.78 374.61 35.0 56.45 61.32 64.69 65.97 75.49 80.21 86.37 87.74 88.51 90.51 96.01 77.48 208.57 37.5 44.95 62.51 65.27 66.76 77.25 83.81 86.79 89.17 90.13 91.51 93.20 75.53 453.94 40.0 67.65 76.77 79.80 80.50 82.02 85.76 88.61 91.42 92.72 93.11 95.72 84.10 107.89 42.5 57.69 66.67 69.92 74.68 80.00 86.83 88.89 90.05 93.28 94.09 96.79 80.52 262.30 45.0 54.55 68.18 74.87 78.96 81.12 88.07 90.57 92.13 92.70 93.75 96.79 81.15 279.11 47.5 72.66 80.17 81.12 82.55 84.85 88.50 89.36 90.97 91.74 93.79 97.41 86.06 78.44 50.0 67.99 71.82 74.98 76.74 85.00 87.30 91.06 93.53 93.80 94.07 95.98 84.05 140.62 52.5 67.46 76.89 78.84 81.48 82.93 87.62 91.28 92.97 93.94 95.97 98.28 83.68 288.56 55.0 73.06 77.97 81.20 84.12 87.08 92.13 93.55 94.19 96.00 96.53 98.64 86.96 164.53 57.5 72.73 78.07 80.02 83.99 85.65 87.69 92.15 93.93 94.84 96.30 99.02 86.50 132.49 60.0 73.51 82.96 85.70 87.72 91.26 93.15 94.26 95.23 95.86 96.50 98.29 87.78 254.53 62.5 63.64 81.12 87.63 88.18 88.80 91.50 93.06 94.74 96.64 97.10 99.76 87.07 247.91 65.0 86.23 89.79 90.00 91.84 93.72 94.56 96.35 96.74 97.00 97.74 99.34 93.91 17.98 67.5 67.07 72.73 77.33 79.43 89.09 91.75 93.35 95.07 96.26 96.94 98.40 84.95 272.23 70.0 78.67 88.69 91.75 92.32 93.78 94.38 95.25 96.23 97.08 97.68 98.84 92.49 46.12 72.5 69.18 90.96 91.20 92.08 94.18 94.85 95.63 97.34 97.73 97.91 99.26 90.54 185.61 75.0 73.14 79.76 88.81 92.08 94.50 95.78 96.51 96.71 97.14 97.43 99.79 90.55 129.44 77.5 76.95 88.46 90.59 92.46 93.69 94.41 95.64 97.96 98.22 98.60 99.37 91.58 120.34 80.0 77.31 87.45 92.44 94.03 95.44 96.30 97.09 98.27 98.38 98.92 99.46 91.09 299.43 82.5 80.42 89.15 93.07 94.83 96.48 97.14 97.57 98.31 98.53 98.66 100.00 92.58 160.69 85.0 81.01 84.79 94.35 95.09 96.32 96.66 97.81 98.52 98.66 98.91 99.24 94.02 47.61 87.5 89.71 94.38 94.98 96.40 96.61 98.06 98.57 98.87 98.93 99.24 99.94 95.48 77.56 90.0 88.00 93.93 94.58 95.64 96.52 98.26 98.94 99.16 99.21 99.40 100.00 95.43 66.75 92.5 93.26 96.01 97.46 97.49 98.55 98.66 99.44 99.84 100.00 100.00 100.00 97.17 36.57 95.0 84.97 95.65 97.13 97.21 97.44 98.36 98.84 99.14 99.14 99.60 100.00 96.30 27.63 97.5 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.99 .01 
First-quartile storms; storm duration 6 to 12 hours

2.5 0 0 0 0 0 1.26 4.57 9.10 11.86 14.43 24.53 7.26 115.31 5.0 6.16 8.54 11.47 13.67 18.96 22.22 26.70 32.61 39.33 42.49 52.96 26.50 340.31 7.5 13.43 16.14 20.01 22.79 27.72 31.45 36.98 44.81 50.16 53.53 65.97 35.15 399.51 

10.0 14.62 23.88 27.08 30.71 35.31 39.33 52.00 57.72 62.40 69.84 82.29 45.07 551.61 12.5 16.31 27.02 31.53 32.73 38.28 44.87 54.51 61.40 67.75 76.91 86.02 48.85 609.83 15.0 24.94 33.83 37.74 39.30 45.20 50.87 58.29 66.38 73.02 77.79 88.16 54.20 522.63 17.5 26.24 37.04 41.71 44.03 50.00 53.64 61.02 65.11 71.18 76.30 87.08 55.90 481.88 20.0 31.53 41.57 45.56 47.49 58.44 64.18 68.73 74.16 79.51 84.78 94.46 62.27 504.04 22.5 33.12 44.62 46.40 50.94 57.42 64.45 70.62 76.00 80.41 83.17 93.48 62.76 493.87 25.0 36.11 48.20 51.46 55.99 59.25 65.60 72.26 77.14 81.88 83.33 88.91 64.71 405.52 27.5 46.87 53.43 58.68 60.61 65.08 70.11 73.75 83.04 86.29 88.39 94.35 69.43 398.19 30.0 46.71 53.45 58.06 61.59 67.83 73.07 77.42 84.00 86.05 87.78 93.64 70.68 350.22 32.5 47.57 53.76 59.08 65.57 72.84 77.74 81.54 84.31 85.91 87.19 92.96 72.61 342.65 35.0 52.38 58.57 63.39 66.32 74.41 80.10 83.16 86.00 86.45 87.67 95.61 75.04 304.82 37.5 58.32 67.14 69.83 72.15 79.55 84.00 86.52 87.80 89.52 90.22 95.00 78.55 271.04 40.0 53.57 65.61 70.51 75.20 78.72 83.89 87.13 89.69 90.46 91.32 96.55 79.36 218.70 42.5 58.55 70.75 73.18 74.20 79.03 84.00 88.16 91.01 91.24 91.36 95.87 80.47 203.92 45.0 59.58 69.75 74.92 77.03 80.57 84.00 87.01 90.36 91.22 91.46 95.17 80.45 215.87 47.5 53.22 64.51 73.60 76.62 80.86 84.47 90.29 92.06 92.30 92.89 96.04 78.92 418.18 50.0 53.60 62.05 69.33 74.61 78.05 81.14 84.00 88.70 89.89 91.87 94.91 76.79 356.95 52.5 53.46 70.78 78.14 79.21 82.86 85.52 90.27 92.68 94.26 95.93 98.29 80.07 490.78 55.0 51.83 67.20 75.07 77.15 80.69 83.92 86.83 92.18 93.20 94.98 97.62 79.73 341.13 57.5 57.49 75.19 80.00 80.74 83.82 86.33 88.15 90.43 92.66 97.43 98.52 82.30 307.56 60.0 61.86 72.11 76.93 82.39 83.32 84.41 88.25 91.59 92.80 95.07 97.13 82.83 195.69 62.5 61.87 76.37 79.84 82.71 85.58 87.55 89.85 92.65 95.94 96.78 98.85 84.02 244.60 65.0 70.87 77.20 79.12 80.00 82.26 83.58 85.93 91.70 92.11 96.28 100.00 83.23 235.41 67.5 59.26 74.93 76.99 79.73 83.33 85.03 89.54 91.46 93.23 96.00 97.62 82.41 233.67 70.0 53.16 76.00 79.79 82.49 84.02 88.03 90.95 93.41 95.02 96.89 99.78 83.20 298.99 72.5 65.89 80.76 82.12 82.70 86.17 89.36 90.78 93.63 94.79 96.90 98.89 86.23 149.03 75.0 75.36 81.06 82.40 84.37 87.05 88.62 93.11 95.21 97.92 98.49 100.00 86.90 208.88 77.5 55.40 80.14 82.78 83.99 86.88 89.76 91.24 94.09 95.67 97.12 99.01 84.26 326.23 80.0 41.07 73.24 82.78 86.27 89.69 91.94 93.53 94.52 95.43 96.90 99.26 82.73 531.28 82.5 42.92 71.19 82.39 83.25 90.22 91.05 93.87 97.25 98.45 98.53 99.13 82.83 501.25 85.0 51.29 77.77 81.63 85.35 88.66 93.15 95.75 97.64 98.31 98.60 99.31 85.18 368.56 87.5 62.79 86.27 87.75 89.07 91.74 95.26 97.14 97.78 98.21 99.02 99.41 88.82 266.89 90.0 72.12 84.65 88.50 89.07 93.34 95.43 97.18 98.02 98.38 98.58 99.53 89.87 188.00 92.5 84.37 90.43 92.05 93.02 94.88 96.67 97.55 98.32 98.64 98.94 99.54 93.45 77.73 95.0 89.43 93.30 94.26 96.29 97.52 98.06 98.58 99.20 99.40 99.63 100.00 95.97 34.47 97.5 97.94 99.46 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.11 8.42 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First-quartile storms; storm duration 12 to 24 hours 2.5 0 0 0 0.38 2.13 4.37 6.94 10.55 12.76 16.07 27.67 9.36 162.77 

5.0 5.07 11.13 13.22 15.24 18.43 21.57 27.22 34.14 37.43 45.04 55.23 27.45 410.08 7.5 9.13 17.40 22.26 24.36 28.05 31.31 36.96 45.95 50.84 55.49 65.21 36.08 444.61 

10.0 15.10 26.36 31.52 33.20 36.37 39.75 48.66 58.26 62.13 65.91 75.00 45.11 500.16 12.5 19.79 30.40 36.22 38.40 42.23 45.90 53.98 64.86 71.53 75.10 85.34 50.70 554.05 15.0 25.00 34.35 40.24 42.84 48.61 52.14 56.72 66.67 75.85 79.85 87.45 54.84 505.40 17.5 33.84 43.34 47.92 50.45 53.99 57.34 62.08 69.74 75.75 81.06 90.03 59.25 443.98 20.0 44.27 50.03 51.62 53.71 57.95 59.97 64.18 73.80 77.16 80.72 88.70 63.25 327.85 22.5 49.60 52.90 54.59 58.04 62.43 65.64 68.66 76.20 79.82 81.24 89.80 66.34 293.39 25.0 52.08 56.01 59.96 63.96 69.78 71.82 74.38 78.43 80.42 83.48 90.38 70.14 263.91 27.5 51.91 57.46 62.81 67.73 74.62 78.25 80.48 82.40 83.62 85.29 90.57 72.89 288.00 30.0 53.52 63.02 68.73 72.37 80.88 82.50 84.17 85.73 86.46 87.78 93.24 76.23 318.77 32.5 52.16 59.60 68.19 72.75 78.64 86.33 88.68 90.63 91.22 91.87 94.00 77.01 409.24 35.0 55.46 62.86 69.43 73.59 82.76 88.46 92.82 93.86 94.81 95.19 96.14 79.97 402.57 37.5 48.43 61.76 67.24 72.79 78.04 86.32 90.38 93.79 94.85 95.79 97.04 78.29 440.68 40.0 48.67 58.33 63.72 73.29 78.27 86.67 90.06 93.69 95.45 96.14 97.95 77.43 510.73 42.5 52.05 59.27 67.01 73.56 80.67 88.81 93.40 94.85 95.45 96.12 98.11 80.41 353.12 45.0 58.94 69.34 73.77 77.63 82.00 89.22 93.40 95.78 96.16 96.60 98.11 83.50 216.87 47.5 53.39 62.31 68.62 74.17 80.23 87.55 91.76 94.34 96.14 96.26 98.12 80.92 316.84 50.0 55.54 67.72 74.37 78.94 82.85 88.77 93.81 95.17 96.26 97.19 98.34 82.86 300.98 52.5 59.01 71.70 80.26 82.86 88.70 91.76 94.50 96.18 96.50 97.19 98.80 85.17 286.65 55.0 63.07 74.68 78.36 80.26 83.94 89.71 91.67 94.25 96.15 97.04 98.24 84.61 200.90 57.5 60.76 65.74 71.27 76.50 86.17 91.50 93.32 96.21 97.07 97.32 98.25 83.53 296.33 60.0 60.86 73.74 81.75 83.46 89.58 92.32 94.28 96.36 96.96 97.26 99.11 85.79 272.64 62.5 62.03 76.10 78.60 79.68 83.88 90.51 93.03 95.26 97.00 97.84 99.23 85.42 180.56 65.0 69.40 80.29 81.75 83.34 87.23 93.49 94.54 96.52 96.72 97.60 99.26 87.15 216.83 67.5 62.73 76.20 81.82 84.47 87.92 93.23 94.77 97.07 97.91 98.36 99.73 86.68 245.81 70.0 61.19 70.83 76.41 78.85 85.10 89.10 93.65 94.92 95.83 97.64 99.83 84.27 264.98 72.5 60.47 64.06 72.89 77.37 85.88 91.10 95.87 97.64 98.06 98.73 100.00 83.93 323.26 75.0 62.27 70.85 75.86 79.17 86.04 89.76 93.68 95.56 97.12 98.18 99.85 85.36 188.94 77.5 64.25 71.98 78.81 82.72 88.36 90.51 93.93 96.86 97.54 98.18 99.08 85.70 242.45 80.0 67.77 80.28 83.90 87.06 91.22 93.84 95.52 96.35 97.22 97.90 99.37 88.35 164.08 82.5 66.47 80.05 84.14 88.53 92.49 94.64 96.85 97.52 97.91 99.00 100.00 89.29 152.81 85.0 72.33 79.44 81.48 84.44 90.98 93.56 96.04 97.04 97.67 98.01 98.53 89.37 101.67 87.5 81.73 87.25 88.54 89.53 91.89 94.76 96.95 97.92 98.42 99.02 99.64 92.31 58.90 90.0 84.94 91.18 91.69 92.19 94.75 96.80 97.75 98.17 98.33 99.06 99.64 94.12 44.06 92.5 83.52 92.15 92.19 92.60 93.23 94.98 97.48 98.26 98.49 98.76 99.51 94.07 34.70 95.0 83.36 89.25 90.68 93.75 94.79 95.76 97.72 98.35 98.72 99.05 99.76 92.67 114.38 97.5 93.80 97.55 98.49 99.44 100.00 100.00 100.00 100.00 100.00 100.00 100.00 97.80 38.82 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First-quartile storms; storm duration 24 to 72 hours

2.5 0 0 0.84 2.55 4.72 7.78 13.15 20.75 23.97 30.54 41.68 16.35 423.15 5.0 8.29 13.60 15.35 17.82 23.59 30.51 37.62 45.61 47.00 51.46 63.57 34.03 523.25 7.5 10.46 21.24 24.77 27.59 33.12 37.50 42.94 50.67 53.13 59.67 71.18 40.75 528.05 

10.0 15.48 25.43 29.55 32.17 35.48 41.66 47.03 53.61 60.39 66.88 79.73 45.09 570.34 12.5 16.51 28.59 32.14 34.53 41.95 50.53 55.63 62.43 70.58 75.47 84.73 50.12 623.08 15.0 23.16 33.20 35.48 40.90 45.09 51.18 55.82 63.93 69.72 71.90 86.94 52.96 511.08 17.5 26.10 34.08 40.79 43.60 48.85 53.29 60.85 65.51 71.24 74.54 87.69 54.88 478.14 20.0 25.05 33.83 35.71 45.47 51.64 55.56 67.50 74.82 78.55 80.19 87.97 57.73 571.25 22.5 33.60 38.11 45.10 46.92 54.22 59.96 70.19 77.75 80.21 81.88 91.66 61.45 465.01 25.0 45.00 52.26 54.50 56.50 59.40 70.52 75.34 81.35 82.52 85.03 96.36 67.98 352.03 27.5 34.86 50.32 52.36 54.65 60.45 63.32 75.54 81.68 86.42 87.50 92.02 66.66 416.79 30.0 29.47 36.81 38.41 47.24 58.22 63.41 66.24 76.35 80.61 88.27 95.48 61.78 565.26 32.5 38.83 48.48 52.09 53.01 54.82 58.12 64.01 69.76 76.34 80.86 90.79 62.27 360.80 35.0 44.67 58.57 60.14 61.30 62.50 63.84 65.33 73.19 77.43 80.90 91.90 66.94 271.70 37.5 50.78 60.75 64.01 64.58 65.32 66.07 67.43 73.60 76.40 81.01 92.39 68.32 259.49 40.0 60.44 66.55 67.17 67.54 68.26 69.48 71.14 80.13 83.27 87.30 96.47 73.70 191.88 42.5 58.64 65.35 67.25 68.40 69.79 71.20 76.36 84.66 87.67 92.41 95.91 74.99 208.01 45.0 59.80 66.88 68.47 69.94 71.35 76.50 85.35 91.38 94.71 95.76 99.24 78.18 317.01 47.5 52.10 67.41 68.82 69.90 71.32 78.41 82.24 91.52 94.86 96.97 98.92 77.61 339.04 50.0 60.00 69.41 69.94 70.00 71.97 73.95 80.39 88.96 95.34 96.75 99.27 78.07 241.96 52.5 56.58 66.21 68.29 69.95 71.99 74.46 81.43 88.67 90.15 92.97 98.98 77.60 217.42 55.0 57.45 66.14 67.74 68.95 73.86 76.36 84.73 90.18 94.38 96.40 99.27 78.29 246.76 57.5 63.11 69.83 72.13 72.58 76.77 82.27 88.36 92.29 96.60 97.29 99.59 81.83 195.41 60.0 49.75 56.59 62.01 64.91 70.07 75.17 80.26 89.99 92.23 97.88 100.00 75.65 298.98 62.5 55.76 64.13 65.82 68.68 71.36 74.54 78.59 82.90 90.75 93.98 98.93 74.92 326.55 65.0 57.95 65.57 67.37 68.97 75.44 80.43 86.47 93.37 95.43 96.96 100.00 78.64 351.70 67.5 46.02 66.10 67.23 72.12 77.20 80.22 82.56 88.37 91.08 95.78 99.41 78.14 294.22 70.0 63.26 70.00 71.60 74.13 78.44 85.41 90.82 95.04 97.26 97.96 99.38 81.97 269.02 72.5 51.37 72.07 75.00 75.64 77.61 81.64 90.55 94.58 95.99 96.50 100.00 81.31 267.23 75.0 54.77 65.15 67.28 70.97 77.61 79.84 84.43 92.62 97.31 98.56 100.00 79.83 254.31 77.5 65.20 72.25 75.53 78.51 81.31 85.33 91.97 96.01 97.96 98.96 99.66 84.57 178.65 80.0 68.76 75.93 77.13 79.22 83.64 88.68 92.97 93.96 97.47 98.50 99.70 86.41 125.11 82.5 68.95 73.48 74.17 78.80 82.84 87.06 93.44 94.15 94.73 96.97 98.80 84.67 172.51 85.0 69.87 74.60 79.33 82.21 84.31 92.43 95.06 97.51 98.23 98.76 100.00 87.71 133.87 87.5 73.40 77.51 78.55 79.80 81.20 81.82 85.59 90.73 94.60 95.48 98.92 84.53 97.40 90.0 74.34 80.80 82.12 82.46 83.07 84.23 89.35 93.80 96.24 98.16 99.59 86.56 103.76 92.5 79.79 82.60 83.47 84.12 87.62 90.61 95.28 96.96 97.59 98.80 99.27 89.61 89.67 95.0 83.00 84.89 86.42 87.56 91.15 93.82 96.26 97.84 98.21 98.91 99.47 91.49 78.77 97.5 89.28 94.80 96.04 97.45 98.98 99.78 100.00 100.00 100.00 100.00 100.00 97.04 24.94 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First-quartile storms; storm duration 0 to 72 hours 2.5 0 0 0 0 0.96 3.72 6.55 10.89 13.70 18.02 31.08 10.11 234.17 

5.0 6.04 10.87 13.19 15.24 18.88 22.84 28.11 35.84 40.81 45.89 56.48 28.34 425.96 7.5 9.36 16.30 20.42 23.59 27.98 31.97 37.31 45.61 50.28 54.66 65.57 35.83 459.47 

10.0 15.06 24.24 28.07 31.65 35.48 39.18 46.75 54.50 60.21 65.29 76.18 43.93 515.55 12.5 18.23 28.02 32.73 35.87 40.55 45.29 53.52 61.81 66.79 74.45 84.05 49.16 572.41 15.0 24.48 33.50 37.68 40.58 46.13 51.18 56.03 64.24 69.01 77.40 86.65 53.29 506.63 17.5 28.39 38.87 43.54 46.80 51.85 56.11 61.52 67.93 71.88 77.16 86.13 56.89 462.25 20.0 34.21 45.59 48.90 51.77 56.70 60.58 67.00 73.83 77.59 81.25 88.51 61.63 420.99 22.5 37.23 49.86 52.43 54.22 60.34 65.07 69.92 76.69 80.00 81.71 90.03 64.64 380.01 25.0 44.38 52.90 56.19 58.77 65.60 70.95 74.10 79.33 81.50 84.00 89.97 68.04 333.28 27.5 47.26 54.65 58.89 61.94 67.96 74.39 79.47 81.98 83.69 86.33 90.67 70.52 332.50 30.0 45.70 56.25 60.05 63.75 70.89 77.93 82.80 85.23 86.05 87.69 93.24 72.18 386.00 32.5 47.52 54.21 57.21 62.17 70.94 77.82 83.62 87.33 88.78 90.32 93.01 72.55 409.66 35.0 53.78 60.73 62.56 63.98 72.10 79.86 86.41 90.13 92.58 93.80 95.81 75.76 356.04 37.5 50.23 63.24 65.00 66.34 72.90 79.67 85.89 89.52 91.25 93.07 96.34 75.61 386.93 40.0 53.70 65.55 67.92 70.12 76.82 81.88 87.41 90.51 92.78 93.70 97.29 78.21 328.55 42.5 54.36 65.56 68.45 70.22 76.80 83.29 88.71 91.89 93.73 94.77 97.21 79.17 281.58 45.0 59.59 68.55 71.03 75.33 80.52 85.07 90.04 92.15 94.40 95.81 97.78 81.37 252.82 47.5 54.16 66.97 70.88 74.58 80.54 84.87 90.30 92.73 94.21 95.78 98.19 80.64 315.09 50.0 58.76 69.44 71.24 73.80 79.38 84.00 88.96 93.53 94.34 95.51 97.90 80.68 278.14 52.5 58.97 70.00 72.29 77.68 82.73 87.62 91.50 94.26 95.89 96.40 98.75 82.24 325.27 55.0 59.08 71.35 74.48 76.82 81.52 85.64 90.60 93.87 94.60 96.20 98.15 82.40 250.17 57.5 62.82 71.12 74.39 78.62 83.90 87.68 91.30 93.98 96.26 97.23 98.65 83.32 252.36 60.0 59.24 70.85 74.74 80.00 83.86 89.51 92.66 94.66 95.68 96.88 98.81 83.50 276.38 62.5 61.48 69.95 73.74 76.67 81.71 86.89 90.66 93.59 95.23 96.88 99.14 82.43 269.22 65.0 65.91 75.84 79.64 81.74 84.97 89.93 93.65 96.15 96.65 97.22 99.40 85.32 247.97 67.5 63.01 71.82 76.96 79.03 84.22 88.18 92.24 94.70 96.30 97.27 99.01 83.65 267.93 70.0 61.59 73.25 77.32 79.71 85.16 89.10 93.28 95.05 96.72 97.50 99.38 84.43 256.09 72.5 60.93 75.00 77.80 81.48 87.23 91.20 94.68 96.11 97.27 97.94 99.52 85.14 258.88 75.0 61.58 74.03 77.75 79.66 84.52 89.40 93.48 96.47 97.32 98.07 100.00 85.16 212.28 77.5 64.93 77.08 80.92 83.29 87.44 90.57 93.76 95.99 97.54 98.19 99.20 85.97 235.81 80.0 68.39 78.04 82.73 86.41 90.67 93.07 95.00 96.37 97.25 98.05 99.37 87.02 273.17 82.5 65.60 75.99 82.39 85.03 90.68 93.75 95.75 97.29 97.79 98.44 99.69 87.28 246.01 85.0 71.64 79.64 81.88 84.27 90.45 94.19 96.15 97.52 98.00 98.43 99.15 88.48 173.67 87.5 76.39 81.77 83.87 86.98 90.10 94.27 96.10 97.77 98.28 98.87 99.48 89.99 123.59 90.0 78.97 83.42 85.83 88.91 92.19 94.85 96.98 98.11 98.44 98.91 99.63 91.07 107.04 92.5 82.46 86.70 89.81 92.00 93.48 95.50 97.38 98.40 98.65 98.98 99.65 92.81 68.87 95.0 83.64 88.58 90.15 91.94 94.79 96.60 97.78 98.52 98.88 99.15 99.72 93.12 85.51 97.5 94.78 98.32 99.18 99.68 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.26 23.11 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 0 to 6 hours

2.5 0 0 0 0 0 0 0 0 0 0 0 0.25 1.42 5.0 .66 1.09 1.14 1.47 1.84 2.28 2.70 4.08 4.54 5.52 10.21 3.47 9.63 7.5 .81 1.84 2.84 4.22 5.16 5.81 7.17 9.38 9.76 11.77 17.19 7.20 28.61 

10.0 1.85 3.81 5.02 5.38 6.30 7.52 9.58 13.30 15.24 17.40 19.33 10.02 61.42 12.5 1.41 2.91 5.14 6.06 8.33 10.04 11.35 13.53 16.67 19.15 25.00 10.89 53.87 15.0 5.97 6.71 6.99 7.51 9.14 10.57 13.91 16.60 17.00 18.72 34.58 14.05 82.57 17.5 .99 7.14 7.61 10.05 11.83 13.23 17.28 20.52 22.66 24.20 26.74 16.31 176.33 20.0 5.75 12.75 13.73 15.69 17.59 20.85 23.51 25.79 26.23 26.70 36.45 20.70 104.74 22.5 2.48 7.01 7.12 7.65 14.43 18.20 22.39 26.71 27.87 30.00 48.51 20.54 271.97 25.0 4.42 8.06 8.32 13.42 24.39 28.23 34.70 36.56 40.72 42.69 51.12 28.16 357.06 27.5 7.25 10.65 15.28 18.71 21.51 26.02 29.36 39.13 41.73 47.71 52.83 28.21 260.76 30.0 5.53 15.26 19.99 23.47 29.86 32.65 35.68 45.25 47.74 52.87 58.73 33.39 311.61 32.5 13.68 30.04 33.69 34.69 40.02 46.53 50.26 58.91 60.47 62.81 73.51 45.66 414.83 35.0 6.98 15.13 25.12 34.22 37.75 44.85 50.92 54.32 57.28 65.33 72.37 42.33 470.58 37.5 19.58 33.33 35.62 38.78 39.88 44.19 50.30 59.38 61.80 66.91 69.73 47.12 371.48 40.0 7.74 38.07 43.07 48.32 50.67 55.71 59.51 66.81 67.12 68.30 75.47 52.08 493.12 42.5 25.09 38.65 48.39 49.35 54.59 59.04 69.87 72.58 73.98 78.30 88.27 59.20 465.26 45.0 15.65 40.00 43.73 50.46 63.95 75.49 76.80 78.70 80.00 80.37 82.95 61.81 604.73 47.5 19.94 39.58 48.95 55.76 59.32 63.86 70.33 78.74 79.48 83.28 90.32 61.09 576.93 50.0 55.54 57.53 61.48 63.19 70.61 74.37 80.45 85.57 86.27 86.50 90.53 73.62 206.49 52.5 45.42 58.18 60.98 64.79 67.62 72.97 79.42 84.05 84.55 87.02 91.66 70.87 392.43 55.0 41.01 54.95 56.28 59.80 67.07 72.18 80.25 87.95 88.21 90.32 92.22 69.51 464.35 57.5 42.06 62.64 66.45 67.21 72.96 79.03 83.55 86.95 89.53 90.58 94.79 74.03 415.54 60.0 30.98 67.36 73.41 74.55 78.18 84.78 86.64 87.99 89.25 89.83 93.55 76.08 458.51 62.5 56.85 67.49 68.63 72.10 73.38 79.18 88.49 89.71 90.13 91.79 95.71 77.75 298.46 65.0 57.88 66.41 68.83 70.15 74.32 76.50 83.47 88.12 90.77 93.09 96.50 77.68 206.98 67.5 70.78 75.90 78.20 78.75 84.14 89.08 92.08 93.64 93.75 95.03 98.18 85.49 139.11 70.0 70.67 76.31 80.62 84.68 90.02 91.69 93.66 94.33 95.03 96.61 98.16 88.08 94.36 72.5 76.65 81.60 83.10 86.21 89.25 91.67 92.40 93.56 94.31 94.98 96.00 88.69 56.92 75.0 80.75 83.38 85.79 88.43 88.70 91.23 94.91 96.11 97.21 97.56 98.74 90.57 53.16 77.5 78.31 84.18 84.63 85.17 91.63 93.13 95.70 97.35 97.65 98.42 98.90 91.26 53.66 80.0 87.55 90.26 90.67 90.80 92.36 94.66 95.85 96.80 97.10 98.71 100.00 93.20 48.16 82.5 88.10 90.69 91.61 92.34 93.09 95.35 96.74 97.23 98.20 98.97 100.00 94.33 22.91 85.0 96.63 97.34 97.81 97.89 98.08 98.26 98.46 98.82 98.89 99.13 99.62 98.25 .92 87.5 92.61 94.50 94.81 95.13 97.28 98.23 98.43 98.60 98.78 98.89 99.38 96.42 16.11 90.0 91.99 94.73 95.80 96.31 97.06 98.27 98.72 98.86 99.07 99.13 99.89 97.09 7.23 92.5 95.33 96.77 97.13 97.53 98.52 98.73 99.24 99.49 99.62 99.93 100.00 98.05 6.12 95.0 94.93 96.13 97.40 98.46 99.10 99.27 99.30 99.41 99.45 99.54 99.81 98.41 2.92 97.5 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.98 .01 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 6 to 12 hours 2.5 0 0 0 0 0 0 0 0 0.73 1.57 5.85 1.96 29.65 

5.0 .80 1.72 1.80 2.00 3.75 4.58 8.37 11.63 17.15 22.18 30.33 10.63 134.98 7.5 .97 1.87 2.43 3.57 5.35 8.69 13.01 25.92 33.58 34.95 41.19 16.50 295.97 

10.0 1.51 3.34 4.86 6.23 9.10 10.84 13.53 29.26 33.95 34.15 40.48 17.29 254.18 12.5 2.00 5.72 7.64 9.37 12.12 14.74 17.00 34.10 34.32 39.81 61.71 22.48 405.46 15.0 3.15 4.71 7.41 9.40 16.37 17.42 22.41 34.13 34.35 34.51 40.69 21.85 265.90 17.5 4.45 7.83 8.22 8.85 12.45 18.25 20.37 34.06 34.51 34.96 56.83 23.36 388.73 20.0 4.34 9.65 13.38 14.54 17.99 21.67 24.49 31.23 34.13 34.28 35.67 22.76 233.41 22.5 6.37 9.98 10.78 12.36 16.80 20.00 26.84 32.20 34.51 40.62 73.84 27.62 501.38 25.0 6.11 11.82 18.79 19.69 23.77 29.15 32.71 37.93 40.62 40.99 74.15 31.48 421.28 27.5 8.31 12.62 15.23 20.38 25.50 31.03 33.56 38.53 40.95 46.47 68.01 32.37 441.68 30.0 11.33 13.99 15.72 20.14 23.89 32.57 33.95 44.07 56.97 70.43 80.41 37.35 599.92 32.5 12.20 17.84 21.17 24.39 34.68 36.72 39.25 48.19 61.56 67.35 84.97 41.46 640.97 35.0 12.11 18.61 24.33 25.48 29.40 37.86 41.35 45.68 61.05 66.29 81.53 41.43 634.51 37.5 17.80 20.40 24.75 25.94 34.39 41.68 44.61 51.97 55.08 63.00 81.59 43.15 504.52 40.0 27.29 31.36 31.81 33.30 43.41 47.18 50.24 61.33 66.56 67.99 84.76 50.37 410.36 42.5 22.23 32.98 40.27 45.58 51.85 53.71 58.04 64.04 68.02 71.38 76.38 53.20 433.08 45.0 32.75 41.43 45.57 49.80 55.12 57.88 60.96 73.35 75.94 78.07 85.22 58.60 392.55 47.5 23.08 40.73 42.60 50.01 60.08 62.29 66.10 75.06 78.00 79.98 87.45 59.85 479.32 50.0 34.11 49.41 53.87 63.49 67.90 72.70 75.62 78.89 80.00 82.48 88.94 67.29 390.88 52.5 28.72 53.24 54.95 56.65 61.74 65.87 67.42 75.02 77.46 80.35 83.30 62.92 386.45 55.0 41.15 56.05 59.89 65.04 68.98 72.49 75.38 82.44 83.36 85.14 89.70 70.07 295.23 57.5 44.54 56.06 62.97 68.57 71.15 75.73 79.17 83.35 83.68 85.53 91.74 71.88 320.18 60.0 57.85 61.36 62.64 63.87 71.50 75.32 82.75 85.24 86.36 88.52 90.28 73.40 282.37 62.5 63.96 66.84 72.00 73.56 79.82 86.03 87.18 88.15 89.77 90.33 91.12 80.75 119.36 65.0 66.63 73.48 74.36 76.86 80.54 84.97 88.28 91.61 91.77 93.56 97.82 82.03 197.26 67.5 65.64 77.06 79.53 80.84 87.83 88.82 90.46 92.76 93.93 94.64 97.08 85.07 137.62 70.0 67.64 77.90 79.82 81.39 83.75 88.90 90.25 93.76 94.51 95.66 98.05 86.17 102.75 72.5 74.20 82.67 82.96 84.08 88.18 89.95 91.29 94.11 95.85 96.42 98.55 87.28 155.13 75.0 67.85 80.81 83.53 84.82 90.93 91.52 92.64 95.25 96.61 97.05 97.96 87.69 136.80 77.5 70.88 85.03 85.37 85.54 92.12 93.21 93.65 94.74 96.08 97.08 98.71 89.06 113.14 80.0 74.79 81.51 85.14 86.69 90.42 93.91 95.55 96.30 97.37 98.44 99.16 90.57 68.23 82.5 80.88 86.82 87.84 88.56 91.05 94.93 96.00 96.92 97.68 97.94 99.50 92.30 40.65 85.0 86.31 89.62 90.50 90.97 95.54 96.77 98.11 98.39 98.65 98.72 99.17 94.11 42.12 87.5 89.31 90.02 91.21 92.25 95.45 97.36 98.43 98.68 98.79 99.18 100.00 95.36 19.01 90.0 89.26 92.51 93.35 93.54 95.43 97.37 97.95 98.93 99.05 99.15 99.79 95.52 21.41 92.5 90.45 94.05 94.91 96.20 97.70 98.93 99.13 99.75 100.00 100.00 100.00 97.03 13.69 95.0 94.25 95.73 96.11 96.96 98.74 98.99 99.19 99.30 99.76 100.00 100.00 98.04 4.39 97.5 99.68 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.68 1.34 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 12 to 24 hours

2.5 0 0 0 0 0 0.25 1.24 2.55 3.80 4.64 9.28 2.83 24.50 5.0 1.30 2.57 3.04 4.46 6.52 9.52 12.42 18.84 22.14 24.74 32.07 13.29 132.74 7.5 3.67 6.36 8.39 10.20 12.90 16.48 25.95 34.00 37.78 41.20 46.42 22.32 265.93 

10.0 7.34 9.14 10.60 12.07 17.13 22.09 31.61 42.38 45.95 49.43 52.38 27.47 332.93 12.5 8.10 11.82 13.51 15.20 18.36 27.28 34.91 37.05 41.87 45.64 54.33 28.48 316.48 15.0 10.15 11.89 15.17 17.47 21.35 30.75 37.06 39.89 43.19 46.41 59.85 31.52 380.99 17.5 11.90 17.48 21.71 22.67 29.99 34.59 39.03 43.68 47.39 51.23 56.27 35.17 349.75 20.0 4.16 11.36 14.18 18.66 23.93 32.01 40.64 47.31 51.66 53.50 63.62 33.79 520.10 22.5 6.48 17.78 21.33 22.97 26.84 36.28 43.57 51.90 52.97 55.13 68.61 37.26 491.84 25.0 13.95 20.97 24.43 29.89 35.52 39.47 42.38 49.70 54.39 58.85 68.93 40.58 440.64 27.5 4.41 13.51 20.99 24.49 33.82 42.68 48.09 53.26 54.33 57.56 79.80 40.52 623.68 30.0 11.84 22.76 25.50 31.75 40.20 44.48 51.27 54.09 57.43 58.55 80.88 44.11 539.05 32.5 15.57 29.07 31.66 38.93 44.18 50.64 54.60 58.64 59.85 65.39 84.97 49.31 495.43 35.0 16.75 29.45 34.58 40.87 50.46 54.39 59.18 64.61 67.84 70.67 88.53 52.75 544.48 37.5 21.62 30.14 36.08 44.29 52.35 55.91 61.18 73.51 76.84 80.05 89.74 55.76 634.25 40.0 17.51 27.92 34.83 39.12 50.68 58.18 63.88 70.19 74.29 80.08 90.49 54.80 645.30 42.5 25.68 37.42 41.20 46.26 54.39 61.61 68.41 72.95 78.47 83.32 92.64 59.92 556.55 45.0 33.33 43.54 46.37 49.70 57.56 64.90 71.61 76.87 79.99 86.58 93.79 63.34 485.58 47.5 39.42 50.21 54.08 58.63 63.11 66.99 72.71 79.30 81.98 86.75 95.36 67.42 401.01 50.0 45.21 52.95 57.93 59.51 68.86 71.04 73.46 79.78 82.35 84.44 95.04 69.73 322.51 52.5 52.70 59.70 63.57 67.57 71.60 75.58 79.98 84.39 85.38 87.50 95.90 73.48 333.76 55.0 51.51 60.02 64.47 68.35 72.09 79.89 83.28 87.12 90.02 91.74 94.87 74.96 355.80 57.5 55.40 60.54 62.25 65.02 71.61 74.03 83.29 88.36 90.66 91.98 95.76 74.38 356.50 60.0 65.03 69.43 72.07 75.19 80.87 86.17 89.47 92.34 93.39 94.62 98.44 82.19 224.52 62.5 59.14 65.60 69.87 71.61 77.30 85.05 89.82 94.59 94.92 95.37 98.62 79.29 386.92 65.0 61.58 71.91 73.29 74.26 80.93 86.13 88.97 93.84 95.72 97.36 99.02 82.08 269.60 67.5 62.05 74.04 75.93 77.66 82.05 87.50 91.33 94.59 95.66 96.27 99.18 83.44 234.70 70.0 61.54 71.73 74.29 77.88 82.22 87.53 93.20 94.73 95.71 97.04 99.47 83.49 246.15 72.5 62.78 71.56 72.72 76.03 81.11 85.90 89.72 94.48 95.39 96.33 97.60 82.05 262.07 75.0 71.48 77.99 81.02 82.24 84.53 88.93 93.49 96.29 97.47 98.00 99.29 85.91 216.81 77.5 69.79 80.87 82.99 83.78 86.54 90.09 94.19 96.58 97.11 97.86 98.75 86.93 178.13 80.0 70.53 76.19 79.63 84.64 87.45 91.78 93.51 96.38 97.22 97.96 98.74 87.91 117.92 82.5 74.12 78.08 78.90 82.95 85.78 92.83 95.73 97.33 98.42 98.64 99.53 88.45 128.41 85.0 80.91 83.02 84.10 85.44 88.16 93.59 95.55 97.28 98.04 98.67 99.49 90.62 72.61 87.5 85.45 87.95 88.42 88.66 90.34 94.47 97.18 98.15 98.75 98.98 99.73 92.78 42.31 90.0 90.48 91.53 91.81 93.54 96.59 97.60 98.63 99.16 99.27 99.37 99.60 95.50 26.58 92.5 88.98 92.81 93.28 94.29 96.94 98.32 98.67 99.10 99.11 99.35 99.62 95.94 21.56 95.0 91.74 95.35 95.72 97.05 98.34 98.99 99.32 99.50 99.66 99.70 100.00 96.49 42.54 97.5 97.62 99.49 99.70 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.89 17.52 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 24 to 72 hours 2.5 0 0 0 0 1.36 2.98 5.22 7.79 10.36 14.03 23.02 7.60 125.57 

5.0 2.45 5.92 7.22 9.83 12.56 19.40 22.99 29.99 37.33 41.37 47.95 23.34 407.61 7.5 4.12 9.35 11.77 13.92 19.28 23.57 34.78 43.48 48.09 50.22 59.46 29.73 462.71 

10.0 2.32 7.71 11.87 15.91 23.21 34.31 54.87 62.11 65.10 67.76 80.54 39.53 856.19 12.5 4.78 8.26 10.05 14.33 21.47 41.22 67.33 73.10 76.46 80.74 89.76 45.11 1,132.90 15.0 3.15 8.30 10.59 17.03 23.53 49.36 68.77 74.78 81.17 82.43 95.78 47.04 1,188.45 17.5 2.59 8.43 11.22 15.48 23.97 30.37 67.02 76.90 79.57 85.20 97.52 45.91 1,283.24 20.0 3.66 8.60 13.38 19.91 25.03 36.33 60.51 77.62 77.94 82.00 97.52 45.14 1,161.42 22.5 3.34 7.60 9.09 13.36 24.51 39.17 46.03 61.55 76.81 82.17 97.52 41.93 1,108.80 25.0 4.83 9.09 16.63 21.54 26.27 30.30 46.73 59.46 69.37 78.60 93.58 42.27 981.92 27.5 5.97 13.18 18.70 26.05 33.20 40.20 51.03 64.52 74.11 79.52 93.56 46.25 938.68 30.0 8.26 19.09 28.79 31.24 34.04 42.76 50.84 59.18 62.02 80.16 91.56 46.71 813.89 32.5 11.43 16.87 22.12 30.16 37.24 41.87 51.12 61.69 64.31 73.68 96.87 46.97 814.93 35.0 10.62 19.33 29.64 37.41 43.43 48.25 54.62 59.97 63.43 68.39 96.52 49.26 752.72 37.5 14.22 27.49 37.79 43.71 50.53 56.32 61.83 64.65 68.60 70.25 83.22 52.85 613.88 40.0 16.88 20.04 25.18 34.57 49.34 58.61 63.33 69.28 72.99 74.64 82.70 52.25 661.63 42.5 23.73 29.59 32.37 38.05 44.40 59.27 66.67 74.73 76.21 78.74 88.45 56.10 604.34 45.0 28.91 43.73 44.49 46.36 53.23 59.78 66.47 74.21 78.09 82.11 98.09 61.12 495.15 47.5 43.55 50.40 53.07 55.12 60.28 63.18 71.64 77.45 82.71 84.44 96.50 65.40 429.48 50.0 43.09 55.49 57.42 60.41 63.61 71.82 78.29 84.70 86.39 88.25 96.73 70.13 420.15 52.5 46.33 59.65 61.15 62.39 63.15 66.67 76.10 78.64 84.65 86.58 98.19 70.29 307.53 55.0 51.20 57.84 61.06 63.13 64.65 70.51 79.04 83.68 87.55 89.59 98.54 72.73 292.22 57.5 59.53 62.93 63.62 66.19 71.00 74.94 81.39 85.23 89.19 90.48 97.93 76.85 181.50 60.0 46.55 61.91 63.83 70.66 76.30 83.39 86.03 89.54 90.94 93.17 98.01 77.93 277.95 62.5 57.02 62.93 64.92 74.63 81.87 86.74 91.86 94.33 94.90 95.55 98.19 81.80 239.19 65.0 63.59 74.74 77.32 80.28 86.59 90.15 95.75 96.60 97.34 97.80 98.35 86.00 179.87 67.5 62.99 69.53 69.69 73.38 84.50 88.22 93.43 96.55 97.01 98.23 98.51 84.04 218.96 70.0 62.94 74.03 78.12 80.87 88.61 93.35 94.92 96.94 98.23 98.48 99.05 85.64 265.21 72.5 61.50 76.94 79.54 81.13 87.42 92.35 93.98 96.09 96.84 96.94 98.36 85.82 216.46 75.0 61.02 78.90 81.53 86.46 91.50 93.65 95.50 96.94 97.25 97.75 99.11 87.54 191.74 77.5 74.65 86.20 89.03 91.23 93.28 94.96 96.37 96.94 97.22 97.67 98.87 91.43 82.81 80.0 68.10 76.92 78.96 85.41 88.50 91.34 94.41 97.15 97.21 98.25 99.10 88.29 123.18 82.5 64.14 72.88 76.78 79.03 91.06 94.26 95.45 97.31 97.49 98.21 99.02 87.32 169.93 85.0 71.12 76.56 77.52 80.91 88.37 92.75 95.75 97.43 97.84 98.25 99.13 88.19 123.09 87.5 67.15 77.98 85.60 87.81 92.75 96.21 97.49 98.33 98.68 99.25 99.48 89.19 238.87 90.0 64.51 71.93 74.92 78.10 82.40 86.98 90.94 96.91 98.22 98.63 99.14 82.40 379.11 92.5 71.91 82.88 85.33 88.04 90.01 94.22 96.58 98.37 98.70 98.80 99.32 89.62 146.31 95.0 86.53 91.07 92.72 93.71 95.93 97.88 98.87 99.32 99.39 99.58 100.00 94.75 52.84 97.5 91.33 95.54 96.66 97.74 98.88 99.88 100.00 100.00 100.00 100.00 100.00 97.57 16.29 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 0 to 72 hours

2.5 0 0 0 0 0 0 1.48 3.65 4.75 6.84 14.75 4.38 72.44 5.0 1.51 2.63 3.63 5.02 7.77 10.56 16.75 22.38 24.30 29.02 39.56 16.74 279.39 7.5 2.81 5.24 7.12 9.31 12.94 17.73 25.04 35.53 39.32 43.51 50.65 23.87 377.11 

10.0 3.28 7.20 8.31 9.71 14.10 21.10 29.38 43.13 50.29 53.36 65.00 29.07 600.77 12.5 3.46 8.70 10.52 12.11 16.13 24.29 34.30 43.53 54.37 63.52 77.42 33.19 761.51 15.0 4.93 9.67 11.70 15.43 19.54 30.38 37.08 46.54 55.04 68.84 81.97 35.89 807.22 17.5 4.75 11.17 12.70 16.48 22.06 27.43 36.85 47.28 54.77 64.74 80.28 35.98 797.56 20.0 4.31 11.01 13.73 17.08 22.31 25.96 34.51 43.72 51.66 57.61 80.50 35.08 754.46 22.5 4.29 9.01 12.90 16.44 22.59 27.91 38.10 46.65 52.40 60.46 82.05 35.60 761.06 25.0 6.45 15.91 19.78 23.17 28.59 34.62 41.09 47.44 55.49 60.74 81.74 38.80 687.88 27.5 5.97 13.21 18.70 22.48 29.93 35.62 44.85 52.41 57.56 64.49 81.25 40.16 727.02 30.0 9.77 19.04 23.60 29.66 33.68 40.13 49.72 54.60 57.66 62.54 84.28 43.32 670.19 32.5 12.52 22.35 27.45 32.75 37.96 43.12 51.37 58.98 61.83 66.67 87.73 46.52 649.48 35.0 12.50 22.71 28.41 34.52 42.42 48.25 54.72 60.64 64.89 68.28 90.69 48.67 668.76 37.5 15.79 26.97 33.83 39.39 47.66 53.32 59.55 64.42 69.26 73.11 83.94 51.79 598.66 40.0 17.75 26.47 31.96 38.03 48.55 55.77 62.91 67.24 71.45 74.81 85.86 52.91 611.61 42.5 25.34 31.63 37.90 43.15 52.02 59.52 66.45 71.76 75.10 78.81 90.04 57.38 559.45 45.0 32.19 43.07 45.21 48.64 56.30 62.32 71.13 76.51 78.69 81.04 92.16 61.71 496.89 47.5 38.67 48.97 52.74 55.52 61.33 64.76 71.46 78.12 81.14 84.30 93.54 64.99 446.05 50.0 43.73 55.59 57.94 61.68 67.70 71.80 76.43 82.33 84.37 86.82 94.53 70.08 356.50 52.5 48.39 57.63 61.04 62.83 66.27 71.60 77.35 81.46 84.33 86.39 94.92 70.53 348.12 55.0 49.44 58.07 60.74 63.41 68.58 73.83 80.83 86.45 87.98 89.87 93.96 72.68 345.40 57.5 57.80 61.80 63.61 67.11 71.62 75.21 81.29 86.19 88.67 90.58 95.65 75.02 289.96 60.0 59.47 65.41 68.35 72.46 76.62 83.50 86.70 89.52 91.04 92.80 96.97 78.52 293.95 62.5 58.96 65.01 69.78 72.96 78.51 86.00 89.21 93.01 94.18 94.98 97.72 80.28 284.26 65.0 63.26 71.96 74.15 76.76 81.01 86.68 90.14 94.08 96.12 97.03 98.48 83.09 225.25 67.5 63.61 72.24 76.10 78.33 84.10 88.82 91.80 94.62 95.81 96.40 98.51 84.29 196.80 70.0 64.10 74.23 78.12 80.75 85.85 90.33 93.67 95.31 96.72 97.26 98.86 85.33 209.86 72.5 68.09 76.24 79.60 81.55 85.85 89.62 92.40 94.85 95.92 96.32 98.00 85.13 205.28 75.0 69.04 80.02 82.37 83.98 88.67 91.67 93.98 96.29 97.16 97.61 98.82 87.28 179.59 77.5 74.86 83.43 84.88 86.02 90.78 93.26 95.05 96.63 97.12 97.75 98.83 89.40 122.02 80.0 73.90 79.44 84.64 86.83 90.23 92.35 94.53 96.86 97.18 98.25 99.08 89.24 105.41 82.5 73.47 78.90 84.34 86.11 91.55 94.26 95.90 97.31 97.71 98.42 99.25 89.64 119.45 85.0 77.02 82.82 84.50 87.35 91.87 95.35 97.07 98.05 98.26 98.63 99.28 90.93 89.54 87.5 78.60 87.95 88.87 89.81 93.71 96.36 97.67 98.47 98.76 98.98 99.60 92.16 121.00 90.0 76.40 86.18 90.48 90.95 93.41 96.59 97.98 98.67 98.96 99.15 99.60 91.02 192.79 92.5 84.47 89.34 91.11 93.26 95.68 97.68 98.59 98.95 99.11 99.32 99.81 93.76 81.48 95.0 89.38 94.18 94.81 95.78 97.60 98.69 99.21 99.36 99.51 99.64 100.00 96.00 41.69 97.5 95.53 98.47 99.48 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.66 12.85 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 0 to 6 hours 2.5 0 0 0 0 0 0 0 0 0 0 3.33 0.57 2.56 

5.0 -- 1.75 2.39 3.19 4.29 5.52 9.49 15.79 18.22 20.74 -- 9.60 71.69 7.5 1.40 2.20 2.74 2.85 6.01 8.25 10.83 11.21 12.73 17.88 28.63 10.16 76.15 

10.0 1.41 4.70 4.86 5.18 8.70 14.78 15.00 15.87 16.73 16.73 32.92 13.25 93.83 12.5 1.11 2.61 3.07 5.27 13.79 14.55 16.67 16.67 19.58 24.62 35.61 14.87 120.06 15.0 -- 3.67 5.48 9.82 17.29 21.12 30.70 33.10 33.10 34.25 -- 20.87 168.75 17.5 6.34 10.51 11.74 13.47 16.67 16.67 19.06 24.13 26.29 28.62 35.61 19.13 82.81 20.0 2.22 7.31 9.33 11.82 13.75 21.67 21.67 28.92 31.81 31.97 33.10 19.30 116.87 22.5 2.31 2.63 3.77 8.83 14.96 18.25 18.60 22.50 22.50 26.25 36.87 16.87 129.44 25.0 4.55 6.12 7.05 8.87 10.92 14.37 19.55 28.21 30.27 32.19 39.12 18.39 147.89 27.5 1.42 8.10 11.52 15.39 23.82 24.17 25.58 29.39 31.46 33.10 35.61 21.76 127.30 30.0 3.86 11.91 15.04 17.08 18.96 25.83 25.83 31.64 35.97 40.15 52.86 25.31 223.08 32.5 7.36 13.04 13.80 15.18 17.46 20.50 28.33 30.88 32.81 33.10 37.95 23.13 138.77 35.0 -- 3.47 3.58 4.95 8.72 15.58 21.30 28.95 33.10 36.01 -- 17.95 186.00 37.5 21.34 28.33 28.33 28.33 28.91 34.05 37.29 39.59 42.15 44.66 55.60 35.50 125.86 40.0 3.87 5.38 13.94 23.23 27.27 30.00 30.00 32.25 32.95 33.87 61.33 27.75 329.93 42.5 2.06 16.80 23.51 24.10 26.36 33.54 34.17 37.06 41.32 45.57 55.10 31.31 313.39 45.0 0 19.92 19.92 19.92 21.26 33.81 34.43 39.73 61.79 83.84 85.03 37.55 747.04 47.5 6.36 10.21 15.89 16.18 30.91 35.59 36.67 37.47 40.68 45.32 61.53 31.49 307.49 50.0 10.31 27.78 28.64 30.69 35.40 41.74 43.81 44.17 47.89 54.29 71.88 41.08 449.13 52.5 19.35 21.72 25.22 28.62 30.26 38.18 45.71 50.53 54.62 56.67 60.96 39.71 282.53 55.0 37.42 39.31 43.22 46.25 52.23 56.86 58.36 61.89 70.71 87.70 94.63 59.40 372.12 57.5 33.18 40.49 40.95 41.25 42.70 49.35 58.04 68.21 78.54 81.67 82.88 56.11 383.25 60.0 37.64 40.84 41.90 46.14 53.11 56.57 61.63 75.36 83.64 84.99 85.00 59.24 445.92 62.5 7.16 47.03 52.83 56.95 61.87 66.19 72.26 81.50 85.83 85.83 87.73 62.41 612.92 65.0 5.95 29.10 43.20 53.72 60.94 62.22 68.40 70.63 72.57 74.64 81.50 55.88 586.07 67.5 35.96 52.89 54.69 58.38 68.18 69.12 73.47 77.19 80.29 83.47 85.83 66.42 347.11 70.0 20.58 63.67 67.01 68.48 75.37 78.40 80.90 85.43 85.83 85.83 93.28 71.45 500.86 72.5 47.10 56.71 58.89 62.62 71.17 72.13 83.67 85.83 85.83 85.83 87.38 71.97 208.07 75.0 50.55 67.45 72.25 73.35 75.62 78.53 82.41 85.55 85.99 86.61 90.85 76.64 180.35 77.5 69.71 81.01 81.79 82.28 83.65 85.83 87.28 90.68 90.99 91.37 93.34 84.79 70.47 80.0 71.75 78.36 79.86 80.88 84.98 85.83 86.41 88.08 89.04 90.15 93.21 83.93 55.21 82.5 70.91 85.26 85.57 85.75 85.83 86.86 88.17 88.74 90.40 92.93 97.27 85.78 121.26 85.0 76.38 82.10 83.46 83.62 90.29 92.86 94.50 95.59 97.97 98.15 98.68 90.16 58.51 87.5 84.51 85.83 85.83 86.51 90.05 91.82 95.09 96.17 96.57 96.86 98.19 91.71 25.23 90.0 85.30 89.93 91.06 91.93 92.50 93.70 96.56 97.00 97.15 97.21 99.28 93.69 18.66 92.5 90.11 93.30 93.57 95.06 96.48 97.70 98.22 98.33 98.41 98.65 98.91 95.84 16.53 95.0 -- 97.20 97.87 97.92 98.05 98.24 98.50 98.81 98.99 99.28 -- 98.09 2.12 97.5 99.17 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.81 .39 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 6 to 12 hours

2.5 0 0 0 0 0 0 0.40 1.66 2.11 2.92 5.83 1.95 17.72 5.0 1.28 2.36 2.40 2.53 3.14 4.42 5.72 8.96 9.16 10.32 14.79 6.79 44.47 7.5 2.16 3.24 3.73 3.98 4.72 6.99 8.79 9.16 11.14 12.23 15.51 7.50 23.38 

10.0 2.06 3.72 4.81 5.73 7.10 8.80 10.88 17.04 19.07 20.81 29.10 12.83 131.02 12.5 2.33 6.17 6.67 9.17 9.67 10.55 11.52 15.57 16.34 18.76 25.06 14.79 257.24 15.0 1.67 3.62 5.03 5.68 11.43 12.83 16.34 18.84 23.57 26.27 37.00 16.69 233.74 17.5 .99 6.17 6.30 6.97 9.83 12.53 13.41 17.27 19.42 21.59 40.42 15.85 274.17 20.0 6.22 11.70 13.57 14.17 14.66 16.34 19.76 24.22 31.34 33.73 44.59 22.42 261.20 22.5 1.91 4.36 6.17 10.62 14.17 14.31 14.77 16.34 18.03 24.50 34.20 16.74 241.02 25.0 2.93 7.82 9.91 10.89 14.17 16.61 23.64 31.12 33.08 37.99 44.84 22.86 357.07 27.5 8.42 11.18 13.48 14.23 14.75 19.67 22.29 31.73 36.03 44.84 49.30 25.32 330.40 30.0 2.39 6.17 12.28 13.60 20.66 27.16 32.14 34.29 40.42 44.84 49.71 26.99 376.43 32.5 1.84 8.52 11.28 11.77 15.87 18.94 26.30 34.33 38.48 43.89 44.84 24.62 364.72 35.0 5.39 8.35 11.85 12.24 15.24 21.31 33.57 37.89 42.57 44.75 51.42 25.71 282.23 37.5 4.60 7.69 11.43 14.17 19.42 21.09 30.22 33.82 42.81 44.84 54.58 29.26 562.71 40.0 6.23 10.74 12.96 14.21 17.58 21.05 28.00 35.89 39.08 44.84 53.67 27.02 378.17 42.5 5.29 12.73 14.23 18.26 21.97 28.00 29.28 38.34 39.92 42.04 53.30 28.84 342.01 45.0 3.50 6.39 7.33 10.12 13.62 17.11 20.40 29.18 32.18 38.47 41.99 20.73 230.05 47.5 3.22 9.66 11.18 14.76 20.38 22.79 24.57 30.67 33.18 42.18 54.58 26.82 465.76 50.0 9.39 13.53 14.26 14.98 20.64 25.54 30.09 33.65 34.82 40.00 48.35 27.57 323.02 52.5 6.08 14.46 19.90 22.59 26.59 29.31 34.16 41.33 48.18 52.94 69.18 34.46 527.12 55.0 10.64 25.93 28.34 30.20 32.22 35.09 41.02 48.84 50.02 53.72 67.36 39.08 406.80 57.5 6.62 18.29 24.23 30.81 34.66 38.11 41.42 49.90 52.40 59.31 71.89 39.33 509.05 60.0 13.42 17.30 24.55 28.75 35.70 41.93 45.99 53.80 55.06 60.55 76.09 42.29 535.55 62.5 20.47 32.22 34.69 35.71 42.96 48.31 51.68 59.55 64.48 71.84 85.55 50.40 513.14 65.0 16.80 30.76 34.18 38.48 47.60 58.82 62.77 65.42 73.80 76.09 81.03 53.35 541.31 67.5 19.72 34.28 40.08 44.52 48.12 57.90 65.12 69.11 74.32 78.94 88.09 56.07 554.17 70.0 21.67 40.72 42.80 47.92 57.90 61.40 65.21 75.23 79.85 81.89 87.82 59.44 510.25 72.5 19.84 44.21 50.33 56.90 61.99 66.93 72.03 81.72 83.02 86.42 90.83 63.63 561.84 75.0 22.95 47.66 53.19 64.39 69.84 72.89 80.89 85.16 86.33 87.38 91.69 67.95 564.67 77.5 44.21 60.12 63.84 67.69 74.90 79.06 84.57 89.52 90.58 92.21 94.01 74.95 358.26 80.0 58.38 70.88 72.62 75.85 82.07 85.76 86.78 89.12 90.45 92.48 96.77 80.67 224.30 82.5 61.66 78.60 80.33 82.29 87.15 89.09 90.41 92.24 93.24 94.34 96.19 84.59 166.94 85.0 65.60 79.37 85.00 86.54 90.15 92.24 92.69 93.69 94.48 95.27 97.21 86.91 158.97 87.5 78.73 85.55 88.73 89.97 92.96 93.59 94.99 95.24 95.51 96.06 97.59 91.16 51.43 90.0 87.15 91.63 92.61 93.97 95.16 96.09 96.82 97.59 97.77 97.95 98.66 94.34 32.77 92.5 91.84 93.71 94.41 94.67 95.91 96.90 97.75 98.13 98.23 98.41 99.36 95.64 18.14 95.0 92.78 95.92 96.38 96.67 97.54 98.06 98.36 98.64 98.92 99.11 99.26 97.12 6.84 97.5 98.29 98.87 99.24 99.42 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.48 .91 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 12 to 24 hours 2.5 0 0 0 0 0 0 0 0.98 1.83 2.54 5.48 1.60 12.14 

5.0 .93 1.58 2.25 2.38 3.06 5.23 5.88 7.33 8.70 9.81 17.72 6.93 47.12 7.5 .87 2.66 4.13 4.42 5.37 5.80 7.64 9.26 10.87 12.78 25.98 9.23 77.94 

10.0 3.25 4.99 5.43 6.05 7.10 7.84 9.15 12.09 14.72 19.33 29.63 12.64 154.35 12.5 3.98 6.76 7.33 8.81 10.10 13.00 15.93 19.76 22.19 25.29 36.57 17.65 237.14 15.0 3.03 7.06 8.24 9.66 11.36 13.92 18.23 19.64 21.62 29.74 38.36 18.08 237.18 17.5 1.72 6.32 7.33 9.12 11.14 13.81 16.72 19.88 20.76 24.60 37.58 16.49 156.25 20.0 2.16 8.70 8.83 9.84 13.17 16.86 20.85 21.94 24.92 28.40 41.41 20.59 320.61 22.5 6.72 11.14 12.71 14.29 16.67 19.88 21.15 26.32 28.84 29.97 39.06 22.63 301.06 25.0 1.44 4.03 7.16 9.75 15.61 19.88 22.66 25.69 29.39 31.83 43.96 22.30 409.78 27.5 2.25 8.18 13.26 14.54 19.69 23.44 31.48 35.81 38.09 45.35 59.46 28.79 514.01 30.0 4.81 9.36 14.76 16.61 20.46 24.69 28.34 38.47 44.71 46.81 74.05 30.28 515.93 32.5 5.83 9.73 13.03 14.74 19.87 22.88 30.09 37.03 48.53 52.15 74.25 31.08 613.62 35.0 6.75 12.44 13.86 16.80 22.23 24.92 31.54 42.51 47.63 54.68 74.56 32.72 557.52 37.5 6.40 11.33 14.00 20.04 22.60 26.92 32.12 35.77 43.13 54.97 75.75 32.63 560.85 40.0 3.56 9.01 14.21 17.87 27.54 36.96 41.13 50.18 55.78 59.44 72.56 36.31 643.10 42.5 3.43 10.39 13.17 16.08 26.37 32.42 40.43 52.34 59.25 62.25 71.83 36.22 631.27 45.0 4.61 13.41 16.46 19.12 25.82 31.48 41.03 53.55 63.87 71.14 77.90 38.79 730.39 47.5 6.67 11.65 15.60 18.04 21.24 27.87 38.57 52.75 62.04 67.28 81.68 37.89 808.69 50.0 7.83 15.24 19.25 20.77 28.40 35.90 39.51 47.13 54.40 59.41 68.60 37.19 532.78 52.5 9.39 17.39 20.18 22.80 29.08 35.14 41.80 47.92 48.99 51.46 77.33 37.83 559.18 55.0 13.67 19.12 21.31 25.30 38.73 43.36 50.00 57.28 59.69 70.00 81.41 45.14 618.73 57.5 21.27 28.57 31.99 38.06 45.13 50.50 58.98 61.68 65.79 73.55 84.89 51.26 533.42 60.0 18.55 25.22 29.89 34.79 44.91 53.47 63.32 68.03 70.90 75.18 87.94 52.19 648.48 62.5 28.52 40.89 45.97 50.60 57.43 61.81 70.14 77.71 82.29 88.49 94.25 62.85 544.26 65.0 31.24 40.51 52.94 58.40 63.89 67.50 74.42 79.56 82.35 86.50 92.18 65.17 508.70 67.5 35.52 50.86 54.21 58.85 68.50 73.08 78.27 84.64 86.27 91.65 96.34 69.61 506.86 70.0 40.71 52.41 58.04 64.86 72.33 76.86 81.91 86.42 88.51 91.06 96.12 72.21 430.50 72.5 32.68 52.06 57.64 64.66 72.62 81.65 83.48 86.89 92.82 94.08 98.08 72.34 564.33 75.0 40.79 55.65 60.74 68.43 76.22 81.75 86.40 89.52 94.39 96.79 98.96 76.07 439.67 77.5 42.04 62.76 68.79 73.00 77.54 83.71 86.66 90.06 91.38 94.29 98.75 77.66 381.28 80.0 57.67 70.80 74.47 78.10 81.93 86.53 87.37 88.97 91.51 94.83 99.11 81.99 205.32 82.5 67.68 76.29 80.22 80.44 87.61 88.75 90.20 92.67 93.66 96.01 98.57 85.47 147.64 85.0 72.33 78.82 80.26 82.12 88.61 91.24 92.81 95.72 97.41 97.89 99.18 87.91 117.18 87.5 78.22 84.78 88.20 90.01 91.45 93.39 95.69 97.29 98.70 99.47 100.00 91.02 95.09 90.0 82.64 86.09 86.95 90.64 92.35 94.91 97.27 97.88 98.41 98.68 100.00 92.69 47.05 92.5 86.62 89.25 89.96 91.56 93.40 96.28 97.27 98.17 98.89 99.06 99.74 93.98 31.26 95.0 85.61 93.10 94.28 94.85 96.57 97.27 98.59 99.18 99.46 99.67 100.00 95.56 29.39 97.5 94.86 98.44 99.09 99.39 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.52 11.80 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 24 to 72 hours

2.5 0 0 0 0 0.52 1.88 3.49 5.41 6.68 7.88 14.06 4.96 62.36 5.0 1.52 3.46 4.33 5.56 6.12 8.27 11.30 15.27 19.07 23.35 35.97 13.96 209.96 7.5 3.21 5.62 6.52 8.11 11.19 13.24 15.66 22.31 25.90 34.34 51.30 19.87 338.69 

10.0 4.88 8.53 10.09 11.19 12.52 16.27 19.07 26.10 40.74 56.28 63.02 25.71 522.06 12.5 4.75 7.74 10.61 11.92 15.95 20.44 23.98 37.58 46.91 64.31 76.61 30.26 713.61 15.0 5.39 9.10 10.57 11.99 13.90 21.44 25.84 33.61 41.43 50.24 78.07 29.54 640.95 17.5 5.99 11.47 12.00 13.50 16.34 25.77 29.28 34.88 42.42 53.12 82.07 31.84 683.55 20.0 6.03 10.69 11.92 13.24 18.64 27.67 36.04 54.33 58.48 61.77 84.86 36.04 775.26 22.5 2.50 7.65 12.59 14.55 17.37 24.14 31.64 45.59 56.80 64.61 77.12 33.21 774.52 25.0 5.61 10.45 11.45 13.62 18.73 25.90 32.25 48.78 58.63 66.55 79.84 35.09 792.09 27.5 9.42 12.03 13.41 15.59 20.51 26.38 31.09 37.62 55.48 68.23 83.96 34.92 742.37 30.0 9.00 14.39 18.41 20.31 25.94 30.73 33.06 40.96 50.37 64.27 80.19 36.82 663.77 32.5 6.80 10.87 11.88 14.42 21.89 27.97 33.15 36.52 37.44 47.92 71.20 31.09 497.46 35.0 6.41 10.24 16.06 17.93 26.40 30.23 35.72 38.86 41.80 56.83 79.30 35.05 668.35 37.5 7.83 12.22 13.55 15.81 20.51 29.66 35.91 40.20 46.04 62.06 76.22 34.65 642.69 40.0 9.31 15.30 17.67 20.23 26.42 32.31 39.03 42.25 47.99 52.23 77.55 35.74 549.02 42.5 10.22 17.16 18.82 21.82 29.51 32.97 40.41 42.99 48.18 54.72 77.11 36.59 469.69 45.0 8.56 13.35 19.08 24.31 28.87 35.83 43.65 50.59 57.92 76.59 81.37 41.06 752.72 47.5 8.39 10.91 13.17 15.67 25.54 33.64 37.18 46.99 52.28 57.09 78.03 35.53 634.62 50.0 10.39 16.11 18.38 19.34 23.04 28.91 36.64 44.38 51.39 58.33 77.06 35.48 549.04 52.5 9.95 23.02 26.48 29.27 34.40 37.97 41.57 44.65 48.42 54.47 75.17 39.61 457.19 55.0 14.93 32.52 36.86 41.44 43.67 48.05 51.78 58.08 60.68 72.96 82.68 49.28 489.56 57.5 14.79 40.09 43.67 46.88 50.34 56.54 63.34 74.70 79.09 80.30 85.48 56.39 580.72 60.0 23.01 39.59 42.85 45.68 51.27 60.62 70.59 77.70 82.95 84.28 91.05 59.54 598.19 62.5 20.55 41.00 43.85 46.17 58.59 64.41 69.07 77.15 84.35 85.25 91.80 60.51 639.15 65.0 19.68 27.19 37.88 44.31 51.42 62.34 67.71 76.12 78.33 79.73 92.20 57.62 668.25 67.5 25.44 40.97 45.96 51.45 59.46 68.21 73.87 79.73 83.59 86.32 93.19 62.94 607.02 70.0 32.10 48.27 53.76 57.28 62.58 69.74 77.39 86.30 89.19 89.19 98.19 67.20 591.25 72.5 28.23 50.42 56.05 62.90 70.48 77.36 83.48 89.19 89.19 92.77 98.54 71.13 609.06 75.0 35.87 50.17 55.85 58.22 68.78 76.21 81.81 88.57 90.50 93.30 98.45 70.63 578.34 77.5 23.75 52.20 58.57 61.82 70.04 77.94 83.47 87.09 89.19 92.81 97.47 70.01 655.75 80.0 31.66 49.48 60.44 64.47 70.86 77.37 82.28 88.07 90.52 94.44 97.72 71.05 604.47 82.5 41.95 57.12 65.54 70.44 78.82 81.90 85.94 89.54 92.56 95.70 97.88 75.95 470.77 85.0 47.41 66.23 71.75 77.12 83.05 87.72 90.63 93.08 94.64 96.32 98.32 80.44 386.57 87.5 54.80 73.05 76.74 81.50 85.95 89.35 94.19 95.67 96.42 97.25 98.44 83.91 302.42 90.0 50.04 68.32 76.50 82.86 86.18 88.45 94.27 97.03 97.26 97.57 98.65 83.34 313.07 92.5 77.31 85.29 86.92 88.33 90.29 92.14 94.58 96.64 97.44 98.03 99.02 90.44 76.19 95.0 89.08 91.78 92.88 94.04 95.18 95.90 96.89 97.91 98.42 98.62 99.82 94.97 21.25 97.5 93.93 97.20 97.74 98.30 98.98 99.59 100.00 100.00 100.00 100.00 100.00 98.21 8.73 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 0 to 72 hours 2.5 0 0 0 0 0 0.30 1.53 3.23 4.45 5.51 9.43 3.40 42.49 

5.0 1.26 2.54 3.11 3.76 5.64 6.77 8.96 12.59 14.98 17.90 27.57 11.53 164.07 7.5 2.30 4.21 4.88 5.72 8.11 10.43 12.38 15.81 17.97 23.98 42.78 15.55 259.64 

10.0 3.66 6.07 6.81 7.84 10.35 12.43 16.65 20.08 23.98 32.15 58.67 20.50 408.50 12.5 3.81 6.78 8.83 9.92 11.99 16.11 19.71 24.06 28.41 37.58 71.05 24.56 563.63 15.0 4.71 7.84 9.57 10.95 12.56 16.34 21.55 29.52 31.75 37.95 61.97 24.60 505.03 17.5 4.92 9.06 9.94 11.62 13.76 16.86 24.33 29.05 32.93 38.12 67.07 25.67 537.10 20.0 6.03 9.97 11.36 13.04 15.51 21.03 26.61 32.94 40.34 45.42 64.97 28.93 590.08 22.5 2.66 7.19 11.58 13.23 15.75 18.20 22.48 29.25 32.88 37.29 66.06 26.18 557.99 25.0 3.74 8.57 10.57 11.47 16.45 21.53 26.50 32.35 35.42 44.84 68.31 28.43 615.53 27.5 7.03 11.81 13.41 14.29 19.93 24.17 30.64 35.31 37.62 49.13 70.70 31.27 610.27 30.0 6.17 13.05 14.76 18.70 22.34 27.56 32.16 38.39 43.69 46.17 71.94 32.62 563.83 32.5 6.61 10.83 11.94 14.36 19.11 23.08 30.51 35.56 37.30 44.84 66.19 29.00 476.52 35.0 6.36 10.22 12.76 16.09 22.58 28.38 34.10 38.93 41.64 48.23 74.26 32.38 583.09 37.5 7.33 12.56 14.29 17.21 21.83 28.38 33.71 39.29 43.23 50.43 75.26 33.28 570.73 40.0 6.20 13.47 15.69 18.73 25.38 30.33 36.90 41.91 45.51 52.23 74.64 34.02 546.30 42.5 7.90 14.14 17.96 20.16 27.80 32.25 38.03 42.52 47.00 53.39 71.75 34.65 481.25 45.0 4.81 11.50 14.01 18.77 24.31 30.89 38.24 44.94 51.28 58.91 78.71 36.22 703.33 47.5 7.27 11.07 13.41 15.88 21.91 27.82 36.23 43.38 48.69 54.98 77.15 34.16 634.13 50.0 9.10 15.50 18.40 19.84 24.29 31.62 37.16 44.03 47.39 54.29 71.02 35.45 517.05 52.5 9.78 20.79 23.09 26.43 30.36 36.69 41.36 45.26 48.67 53.08 73.52 38.21 490.02 55.0 14.58 26.70 30.90 34.88 41.82 45.62 49.87 56.90 59.32 65.09 82.01 46.71 530.01 57.5 16.18 31.25 36.59 40.41 46.14 51.08 59.11 65.48 72.40 78.76 84.70 52.30 579.71 60.0 18.55 29.88 36.00 40.78 46.66 53.88 62.39 70.59 75.54 81.34 88.13 54.26 633.47 62.5 23.70 37.31 42.46 45.76 54.33 61.11 67.22 75.05 78.06 85.22 91.96 59.47 605.31 65.0 20.17 34.34 40.45 46.36 56.66 63.24 67.69 75.89 77.86 79.80 90.21 58.83 620.02 67.5 25.63 44.04 47.90 52.54 59.48 68.58 73.75 79.73 82.58 85.83 93.54 63.80 573.08 70.0 32.72 46.90 53.37 57.98 64.10 71.25 77.39 83.00 86.68 89.19 96.09 67.35 548.14 72.5 28.22 50.32 56.13 61.37 67.51 75.42 82.47 86.94 89.19 90.73 97.47 69.89 583.43 75.0 35.91 52.96 57.14 63.24 71.48 77.35 83.09 86.88 89.29 91.68 97.89 71.88 527.40 77.5 37.20 59.42 62.42 66.37 74.52 80.39 84.91 89.19 90.50 92.56 97.47 73.88 506.78 80.0 44.02 63.76 67.04 71.55 78.41 82.47 86.46 88.75 90.49 93.31 97.47 76.55 422.12 82.5 52.70 69.65 73.99 79.02 82.42 86.17 89.06 91.36 92.97 94.74 97.66 80.67 328.89 85.0 60.00 75.59 78.23 81.50 86.81 89.74 91.94 93.76 95.06 96.32 98.42 83.93 276.33 87.5 71.86 81.04 83.61 85.69 89.88 92.51 94.55 95.81 96.77 97.47 98.96 87.51 200.40 90.0 67.20 82.96 85.22 86.92 90.60 93.71 96.01 97.25 97.55 97.96 98.96 88.25 204.80 92.5 82.68 88.14 89.29 90.55 92.83 94.67 96.61 97.68 98.10 98.42 99.30 92.50 57.29 95.0 89.72 92.90 94.19 94.87 95.82 96.96 97.90 98.54 98.68 99.01 100.00 95.59 20.93 97.5 95.63 98.13 98.63 98.96 99.62 100.00 100.00 100.00 100.00 100.00 100.00 98.64 7.80 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 0 to 6 hours

2.5 0 0 0 0 0 0 0 0 0 0 2.33 0.49 3.54 5.0 -- -- -- -- 2.69 3.63 4.57 -- -- -- -- 3.63 2.45 7.5 -- -- -- -- 3.22 7.24 11.27 -- -- -- -- 7.24 45.04 

10.0 -- 1.18 1.93 2.69 7.11 12.99 13.86 14.66 15.00 15.33 -- 9.37 38.16 12.5 -- -- -- -- -- -- -- -- -- -- -- -- -- 15.0 -- -- 5.85 8.23 12.99 17.75 19.54 21.33 22.22 -- -- 15.27 47.73 17.5 -- -- 3.09 8.29 18.68 29.07 29.44 29.81 30.00 -- -- 20.72 155.52 20.0 -- -- -- -- 4.42 11.04 17.66 -- -- -- -- 11.04 121.86 22.5 -- .27 .68 1.08 3.36 6.38 19.23 29.79 32.79 35.78 -- 14.66 233.52 25.0 -- 7.98 8.76 9.55 11.11 22.42 33.72 36.31 37.60 38.89 -- 22.92 183.59 27.5 -- -- -- -- 6.29 13.19 20.08 -- -- -- -- 13.19 132.03 30.0 -- -- -- -- 8.47 19.88 31.29 -- -- -- -- 19.88 361.36 32.5 -- 5.41 7.22 7.95 12.43 25.97 27.72 34.60 38.89 39.61 -- 21.81 206.74 35.0 -- -- -- -- -- -- -- -- -- -- -- -- -- 37.5 -- -- 2.61 4.64 8.70 12.77 18.22 23.68 26.41 -- -- 13.93 95.07 40.0 -- -- -- -- -- 2.94 -- -- -- -- -- 2.94 0 42.5 -- -- -- -- -- 52.33 -- -- -- -- -- 52.33 0 45.0 -- 5.10 6.23 7.36 16.00 27.84 28.90 31.46 34.25 37.03 -- 21.76 176.27 47.5 -- -- -- -- -- 26.41 -- -- -- -- -- 26.41 0 50.0 -- 6.62 11.14 15.65 24.69 28.56 32.43 44.12 49.97 55.81 -- 29.89 311.79 52.5 -- -- 0 2.55 7.66 12.77 18.40 24.03 26.84 -- -- 13.20 120.16 55.0 -- 8.70 12.77 16.85 25.00 31.94 38.89 41.83 43.30 44.77 -- 29.34 193.54 57.5 -- -- -- -- 34.02 42.19 50.37 -- -- -- -- 42.19 185.54 60.0 -- -- 0 2.79 8.38 13.97 21.58 29.19 32.99 -- -- 15.65 182.80 62.5 -- 3.10 6.66 10.23 18.18 26.54 29.58 35.72 41.89 48.06 -- 24.73 305.44 65.0 -- -- -- -- 6.26 12.42 18.58 -- -- -- -- 12.42 105.38 67.5 -- 16.39 23.50 29.60 36.83 39.14 41.25 47.72 48.76 48.92 -- 35.48 195.62 70.0 -- 8.37 14.21 18.41 18.57 22.08 26.15 28.27 42.73 62.56 -- 29.67 689.33 72.5 -- 14.58 18.64 22.62 29.58 33.61 37.24 40.71 42.42 42.72 -- 30.43 142.87 75.0 -- 27.80 28.81 29.83 34.10 39.50 40.98 43.36 45.45 47.53 -- 37.60 62.21 77.5 -- 39.65 40.56 45.20 53.93 61.01 61.95 71.50 77.70 82.10 -- 60.09 293.30 80.0 -- 27.94 31.55 35.16 42.37 51.58 60.79 61.13 61.30 61.47 -- 48.14 194.76 82.5 -- 6.91 17.28 27.65 42.44 54.26 55.19 59.90 66.04 72.17 -- 44.18 662.07 85.0 -- 29.71 46.11 49.70 58.53 72.29 86.39 91.27 92.17 92.71 -- 64.89 895.56 87.5 -- 28.56 34.67 40.78 52.07 62.89 65.90 74.11 83.41 92.72 -- 59.81 615.16 90.0 41.82 60.06 60.22 63.05 75.53 84.93 91.08 95.54 96.00 96.46 99.02 78.61 366.56 92.5 -- 62.86 71.43 72.27 76.05 86.11 90.71 94.14 95.65 97.25 -- 81.17 259.20 95.0 -- 85.59 86.39 87.18 88.78 92.44 96.10 98.05 99.03 100.00 -- 92.62 32.69 97.5 95.95 99.04 99.73 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.91 8.22 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 6 to 12 hours 2.5 0 0 0 0 0 0 1.00 2.40 3.88 5.59 13.92 3.38 36.79 

5.0 1.57 2.63 2.97 3.70 4.55 5.41 10.95 15.12 21.75 22.96 24.77 10.45 78.31 7.5 .99 3.12 3.77 4.06 5.94 11.65 14.88 23.21 24.05 25.00 25.50 12.87 97.03 

10.0 1.18 4.40 4.82 5.77 9.80 14.58 20.45 24.82 25.00 25.51 32.00 16.26 148.48 12.5 0 4.10 4.90 5.66 10.62 18.18 23.84 25.41 25.81 27.25 34.01 17.25 163.46 15.0 6.67 10.84 14.04 15.63 23.57 24.78 26.52 28.31 29.67 31.49 33.00 22.52 109.74 17.5 1.71 8.47 10.00 10.66 14.04 24.13 27.74 28.43 29.61 32.27 39.97 20.98 173.41 20.0 8.90 9.48 10.25 15.62 20.58 25.59 28.49 30.16 30.89 35.38 39.61 23.79 127.54 22.5 9.03 13.17 14.44 15.80 23.38 30.30 35.48 40.07 40.99 41.25 48.76 29.00 241.14 25.0 2.52 16.16 21.46 25.72 28.88 30.17 32.81 39.67 41.25 41.65 43.63 29.32 185.53 27.5 6.48 13.52 13.89 20.68 29.47 31.52 32.27 33.56 41.25 42.93 43.38 27.90 163.10 30.0 12.02 17.75 22.53 24.94 32.20 33.70 38.38 41.25 42.34 43.43 44.34 31.71 138.03 32.5 1.83 8.99 24.02 25.46 28.00 32.20 32.88 38.23 41.26 44.65 47.09 29.35 289.19 35.0 23.02 29.09 29.86 30.67 33.76 37.84 42.86 45.46 45.52 45.54 47.44 36.87 103.42 37.5 3.34 12.34 14.88 15.81 17.54 27.00 35.74 41.68 45.54 45.54 45.96 27.14 243.87 40.0 4.45 27.64 29.14 30.33 32.20 32.67 37.34 42.33 45.13 45.88 46.41 33.92 206.50 42.5 7.89 17.85 27.00 28.34 32.20 35.95 41.25 45.11 46.23 46.47 47.32 33.15 199.48 45.0 4.94 5.90 12.09 17.39 19.38 24.26 31.24 37.66 38.46 39.48 50.81 27.06 338.48 47.5 17.48 24.45 27.26 28.02 32.20 33.33 40.09 42.81 44.69 45.91 59.54 35.97 236.16 50.0 -- 14.76 22.54 24.19 28.00 33.33 41.81 44.61 45.06 45.62 -- 31.58 210.87 52.5 .76 8.02 11.00 14.18 25.58 29.84 32.20 33.45 37.52 43.50 62.85 28.67 414.07 55.0 8.20 14.49 19.03 24.20 25.96 28.57 37.09 40.28 46.97 47.52 62.98 32.91 355.40 57.5 2.57 13.13 14.40 16.25 27.85 30.88 33.90 42.15 44.83 45.54 59.16 30.25 353.04 60.0 2.53 12.86 16.54 18.31 23.18 32.36 35.59 41.85 42.92 45.14 58.83 31.15 408.88 62.5 1.42 10.36 18.83 19.35 20.87 31.14 36.76 37.59 38.08 42.87 72.57 30.65 433.23 65.0 3.56 5.56 6.21 10.75 30.88 42.42 43.37 50.05 53.98 60.57 78.87 36.54 644.33 67.5 5.76 19.54 26.09 29.28 40.06 41.53 44.92 46.14 55.24 60.49 83.92 42.12 594.73 70.0 3.44 8.69 9.90 17.35 23.08 38.81 47.19 48.81 50.74 51.81 58.72 33.85 500.52 72.5 5.75 25.44 28.43 30.86 38.95 42.78 49.63 53.35 59.24 64.66 90.09 44.86 596.92 75.0 12.89 29.55 33.33 34.54 45.68 53.57 54.24 57.35 70.89 73.91 89.83 50.18 613.26 77.5 16.60 34.53 38.39 39.51 44.64 46.21 48.73 54.24 54.24 58.33 89.96 47.98 497.78 80.0 38.96 44.98 45.90 47.42 49.40 53.97 58.35 61.61 64.01 66.93 86.59 54.90 348.17 82.5 36.98 49.50 50.30 50.63 59.07 61.41 65.04 73.85 75.13 77.32 92.00 61.77 391.23 85.0 35.59 50.04 52.54 53.45 72.03 76.73 79.40 81.18 87.73 89.33 94.88 69.21 523.52 87.5 40.51 52.53 53.68 66.15 77.81 83.09 83.90 88.38 90.89 91.43 94.31 73.62 441.50 90.0 25.22 55.12 58.00 63.01 79.25 87.46 91.32 93.89 94.35 95.01 98.31 75.15 642.38 92.5 43.29 64.51 72.71 78.58 82.32 91.77 94.40 95.50 95.98 96.33 98.31 80.80 448.20 95.0 44.99 71.54 77.47 86.08 92.45 96.15 96.92 97.18 97.83 98.07 100.00 85.07 406.46 97.5 84.49 96.44 97.48 98.18 99.00 100.00 100.00 100.00 100.00 100.00 100.00 94.48 180.53 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 12 to 24 hours

2.5 0 0 0 0 0 0.34 0.98 3.01 4.84 6.61 13.30 3.86 45.61 5.0 1.39 2.38 2.74 3.04 4.83 6.58 8.28 13.14 13.87 17.38 21.58 8.76 53.14 7.5 1.79 2.66 3.34 4.25 5.82 7.44 8.64 11.83 14.77 19.15 21.58 9.60 62.09 

10.0 1.46 3.70 4.32 5.36 7.73 8.29 9.27 15.97 17.59 18.95 23.42 10.66 55.41 12.5 0 3.66 5.24 7.30 8.06 9.20 10.87 19.05 19.54 21.58 25.74 12.23 82.88 15.0 1.12 3.66 4.73 4.94 5.73 7.77 9.73 12.13 15.99 19.09 23.97 11.17 138.11 17.5 .72 1.80 3.06 3.23 5.67 7.84 8.54 12.34 17.75 19.11 28.02 10.74 116.29 20.0 4.87 6.29 6.89 7.09 8.22 9.31 10.89 13.31 20.08 23.35 35.24 14.87 209.92 22.5 1.15 4.00 5.10 6.47 8.23 10.95 12.44 12.82 13.63 20.11 26.28 12.04 90.59 25.0 6.75 10.37 12.60 13.33 15.26 16.77 18.88 20.73 21.59 23.17 34.08 18.84 174.14 27.5 1.21 9.90 13.88 17.08 20.96 22.98 28.97 31.14 32.78 34.16 47.87 24.94 300.36 30.0 2.71 9.28 13.87 14.90 17.23 21.37 23.57 25.83 28.13 32.20 36.14 20.99 155.82 32.5 1.35 9.55 9.82 18.19 20.11 24.87 28.73 34.38 35.90 39.17 45.96 26.26 365.61 35.0 1.67 5.80 7.50 9.55 19.57 21.46 25.70 31.86 37.07 38.54 44.87 24.17 391.92 37.5 3.35 7.78 9.09 15.35 24.00 26.88 29.81 33.99 36.05 40.86 47.39 27.16 349.09 40.0 6.66 13.48 13.72 17.88 26.71 29.12 32.15 40.65 42.03 42.98 48.90 29.86 306.80 42.5 5.20 8.15 10.61 12.91 15.34 25.61 29.72 35.41 42.68 45.34 49.71 27.24 421.96 45.0 8.27 10.87 14.69 18.33 19.86 32.38 35.48 41.75 43.54 49.33 52.67 30.78 406.10 47.5 10.43 15.25 19.40 20.40 23.46 25.61 31.71 37.99 42.11 43.54 53.01 30.68 334.16 50.0 11.28 19.08 21.49 21.86 29.26 33.66 37.23 42.68 44.48 46.98 49.46 32.82 246.20 52.5 11.19 16.39 21.49 23.56 31.61 38.83 42.68 46.50 48.85 51.57 56.68 36.64 377.82 55.0 13.99 21.49 22.64 28.77 32.54 39.89 42.71 43.16 46.12 49.03 57.67 37.51 329.49 57.5 17.09 21.86 25.36 25.56 32.37 42.68 43.16 48.99 49.52 54.81 60.24 40.43 418.64 60.0 16.14 18.87 21.86 23.30 33.40 39.89 43.16 48.43 49.52 53.13 59.52 38.76 395.86 62.5 17.06 21.84 23.77 25.61 38.11 42.71 45.15 50.00 52.53 57.67 61.75 41.12 404.72 65.0 16.54 20.93 22.28 23.89 27.82 36.17 39.89 48.68 53.06 57.67 58.36 38.09 403.46 67.5 24.06 30.39 33.74 36.33 39.50 40.84 44.64 49.51 55.70 58.09 84.65 46.59 425.01 70.0 18.50 24.06 24.61 29.33 36.69 39.86 41.35 45.29 46.49 48.31 58.52 37.89 232.23 72.5 24.84 30.53 36.59 40.06 45.03 46.47 50.30 53.85 57.67 60.08 94.03 50.19 475.37 75.0 12.46 25.13 30.51 36.45 42.80 48.68 53.78 55.48 57.97 59.62 77.19 46.26 473.49 77.5 25.53 32.95 34.32 38.90 46.10 51.07 56.89 60.32 65.19 70.83 89.43 52.58 459.77 80.0 13.93 31.18 40.40 43.24 48.72 55.56 59.05 63.55 67.86 69.66 85.36 52.73 573.10 82.5 17.14 29.44 37.54 46.22 49.46 55.56 61.91 69.17 73.19 83.45 90.24 55.51 632.99 85.0 26.38 31.05 33.36 37.94 46.59 51.77 60.56 71.43 74.78 80.42 88.71 55.31 574.73 87.5 29.06 38.14 44.56 49.15 54.82 62.97 70.99 75.86 79.52 83.75 93.09 61.19 559.93 90.0 33.46 54.08 59.75 64.46 74.90 79.17 82.50 85.95 87.28 89.37 95.60 71.42 540.48 92.5 27.77 52.12 64.03 79.98 84.57 88.55 90.23 91.81 92.44 93.11 96.13 75.87 651.77 95.0 43.22 53.34 65.57 74.97 89.40 93.22 94.14 95.44 96.08 96.68 97.82 80.22 526.16 97.5 75.54 91.15 94.02 95.47 96.96 98.06 99.13 100.00 100.00 100.00 100.00 92.49 215.88 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 24 to 72 hours 2.5 0 0 0 0 0 1.18 3.23 5.88 8.22 9.99 18.41 5.04 52.83 

5.0 1.15 3.04 3.33 3.96 6.70 10.65 13.72 20.92 23.93 29.36 31.40 14.27 164.37 7.5 2.08 4.03 5.96 6.67 8.14 11.41 15.90 23.62 29.30 31.36 32.96 16.35 184.76 

10.0 3.14 7.11 7.81 8.96 10.75 14.83 19.69 24.88 30.82 31.61 35.15 18.93 210.05 12.5 1.11 2.66 5.21 6.24 9.81 11.38 16.25 19.86 28.52 30.81 31.72 16.82 257.72 15.0 2.62 7.56 8.81 9.91 12.02 15.09 20.16 23.28 25.45 31.18 31.72 18.51 195.23 17.5 3.13 9.67 11.57 12.22 15.42 19.56 23.36 25.81 30.03 31.51 33.33 20.73 192.19 20.0 3.45 6.06 8.23 11.43 15.63 18.50 24.01 26.44 31.67 32.00 36.45 21.29 266.32 22.5 3.97 6.55 8.64 10.03 12.63 18.48 22.71 26.79 27.28 33.60 38.36 20.73 245.17 25.0 6.22 9.77 10.96 11.40 12.79 20.89 23.85 28.25 31.98 34.52 40.32 22.52 241.19 27.5 11.49 13.67 14.46 15.41 18.96 23.81 28.27 32.95 33.94 37.43 46.33 26.86 272.55 30.0 9.35 14.72 16.46 18.09 22.62 30.39 32.22 36.55 40.20 41.08 50.70 29.94 287.67 32.5 9.25 15.58 16.98 18.10 20.15 22.41 32.96 39.18 41.07 41.90 46.64 28.36 243.36 35.0 12.03 19.76 20.72 21.38 24.43 30.74 36.74 41.75 43.37 44.16 47.24 32.38 288.63 37.5 12.57 21.56 22.13 23.12 25.18 26.62 29.77 36.34 41.73 42.54 50.49 30.88 218.75 40.0 12.66 22.90 24.76 26.73 29.85 32.09 36.48 40.97 42.08 44.90 47.24 33.44 222.28 42.5 24.57 26.93 27.84 28.90 30.84 32.98 37.35 42.08 43.81 46.03 49.54 36.45 214.09 45.0 12.31 17.64 19.43 24.74 27.90 36.05 38.50 40.65 42.08 44.19 47.41 32.73 250.63 47.5 13.36 17.81 20.96 26.03 31.36 35.13 39.31 44.21 45.86 48.02 57.08 35.25 298.71 50.0 11.18 26.98 28.63 30.14 35.52 39.81 42.66 47.61 48.35 49.10 61.33 39.56 392.56 52.5 12.15 20.34 21.77 25.82 33.29 38.02 43.03 46.81 48.47 49.58 58.20 37.11 323.96 55.0 14.85 25.11 27.97 28.65 36.93 42.08 45.05 46.98 47.99 48.86 53.18 38.85 236.90 57.5 10.50 19.01 25.71 28.54 30.41 38.75 44.18 46.98 48.57 49.46 58.34 36.90 343.75 60.0 19.46 27.47 30.57 32.97 39.49 43.37 46.58 49.16 50.04 51.07 59.10 41.43 255.35 62.5 22.89 30.12 31.84 33.51 41.15 46.98 50.83 52.62 52.99 54.64 59.19 43.92 244.10 65.0 19.33 31.22 32.12 33.01 39.66 45.66 51.68 55.31 56.21 57.05 61.63 44.15 323.13 67.5 20.85 26.37 33.51 34.50 41.20 45.17 52.88 56.18 58.15 59.34 63.84 44.91 322.78 70.0 17.92 31.59 35.87 37.90 44.49 46.35 47.82 55.44 57.24 60.72 67.88 45.44 319.62 72.5 23.21 27.69 32.77 33.19 38.44 46.99 49.86 54.21 57.12 58.26 78.82 46.70 359.50 75.0 27.52 31.49 34.83 36.17 43.25 49.61 55.88 59.46 61.51 62.18 72.18 49.61 332.05 77.5 30.42 36.84 41.05 44.92 47.66 55.02 59.23 63.30 64.26 64.79 75.69 52.50 376.41 80.0 32.32 36.50 41.04 46.75 53.70 58.12 62.01 64.24 65.93 68.17 78.03 54.97 338.45 82.5 37.66 45.72 48.95 51.34 54.47 60.90 64.44 68.93 70.76 73.91 81.54 59.35 332.47 85.0 35.34 52.96 55.41 58.49 62.70 69.12 73.35 76.92 79.85 81.69 86.54 65.27 359.41 87.5 38.12 54.84 58.15 59.83 65.75 72.66 78.28 84.21 86.50 87.89 91.59 69.33 415.69 90.0 50.54 61.44 62.99 63.82 71.50 77.16 83.87 89.09 92.12 94.29 98.61 76.11 322.50 92.5 55.43 67.96 70.87 74.98 79.40 86.29 90.80 93.53 94.82 96.84 99.15 81.68 257.52 95.0 64.29 75.55 78.51 80.63 85.51 89.68 93.44 95.14 96.04 96.81 99.15 85.52 186.74 97.5 84.59 92.74 94.34 95.48 97.28 98.26 99.31 100.00 100.00 100.00 100.00 95.07 67.02 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 0 to 72 hours

2.5 0 0 0 0 0 0.38 1.67 3.96 5.33 7.97 14.76 4.17 46.68 5.0 1.48 2.48 3.05 3.36 5.14 7.23 11.47 15.86 19.15 21.58 29.36 11.64 117.57 7.5 1.90 3.37 4.25 5.64 7.34 9.04 13.58 18.88 21.68 24.45 31.43 13.73 142.98 

10.0 2.40 4.56 6.41 7.53 9.21 12.07 16.78 20.67 23.12 24.73 31.71 15.47 156.56 12.5 1.11 3.70 5.26 6.74 9.10 11.11 18.38 21.49 24.76 25.96 31.72 15.65 190.00 15.0 2.60 5.50 7.18 8.06 10.87 14.04 19.13 23.12 24.72 27.71 31.71 17.14 176.18 17.5 1.66 5.66 7.84 8.47 11.75 15.42 20.41 25.72 27.88 29.50 32.87 18.05 187.01 20.0 4.00 7.05 8.39 9.32 11.71 17.70 22.16 26.37 30.14 31.82 36.06 19.99 231.51 22.5 2.61 6.25 7.94 9.72 12.44 14.80 21.19 26.76 28.74 33.97 39.62 19.77 236.54 25.0 6.91 10.38 11.43 12.60 15.44 19.35 22.07 26.99 29.97 32.72 41.25 22.13 217.34 27.5 4.84 13.14 13.95 15.95 21.31 24.68 29.82 32.31 33.60 35.18 43.33 26.11 266.43 30.0 8.58 13.87 15.95 17.38 22.44 26.99 32.20 35.29 38.01 40.20 43.93 27.55 242.25 32.5 5.60 11.79 16.31 18.41 21.43 25.30 32.18 36.38 39.46 41.30 45.26 27.59 290.43 35.0 8.39 13.55 20.11 20.87 24.49 29.35 33.86 40.41 42.08 43.93 47.24 30.44 313.09 37.5 7.88 13.00 16.46 21.56 24.56 26.64 29.77 35.71 41.02 42.08 46.20 28.57 271.76 40.0 11.46 17.08 24.19 26.05 28.99 32.00 34.65 40.91 42.27 44.34 46.56 32.07 256.15 42.5 10.52 14.82 24.06 26.48 28.88 31.44 35.67 41.25 43.81 46.25 49.35 32.72 309.82 45.0 8.21 14.17 17.77 19.35 24.83 31.88 36.53 39.60 41.75 43.97 50.50 30.86 322.64 47.5 11.96 19.18 20.68 21.45 26.87 32.20 37.02 41.79 43.89 45.80 53.43 33.27 309.69 50.0 11.11 20.54 22.98 26.99 31.02 35.37 40.52 44.62 47.00 48.14 54.96 35.39 318.10 52.5 9.81 15.92 20.99 22.43 31.41 35.78 41.57 45.24 48.15 49.03 57.67 35.38 372.80 55.0 13.96 21.86 25.08 28.04 33.07 39.17 43.16 45.88 46.98 48.68 56.35 37.34 292.69 57.5 12.62 19.84 23.42 26.53 30.31 38.58 43.16 46.98 48.69 49.58 58.28 37.11 379.52 60.0 15.91 21.87 25.74 29.79 35.53 39.89 43.91 48.17 49.51 51.04 58.15 38.81 337.99 62.5 16.98 24.24 27.07 30.64 37.01 42.71 46.46 51.75 52.59 54.15 60.39 40.78 343.74 65.0 16.59 22.36 24.61 30.73 35.01 40.12 46.30 53.05 55.62 57.03 59.96 40.83 404.37 67.5 19.85 28.40 32.13 34.64 39.66 43.14 46.98 54.26 56.18 58.39 72.06 44.56 399.60 70.0 12.29 22.45 24.11 28.94 37.73 42.09 46.27 48.31 51.52 56.36 63.41 40.19 370.34 72.5 23.29 27.85 32.56 33.97 40.75 45.81 49.48 53.05 56.37 58.30 81.71 46.82 441.57 75.0 25.13 30.36 33.74 36.16 42.82 48.90 54.24 57.69 59.90 62.05 77.87 48.51 417.96 77.5 29.42 36.39 39.35 42.28 46.33 52.32 56.84 61.77 63.39 65.63 79.49 51.96 423.84 80.0 28.39 39.26 42.37 46.30 49.59 57.67 59.46 63.53 65.28 68.26 79.55 54.24 403.40 82.5 29.59 44.92 47.88 49.62 53.62 60.17 63.91 69.20 72.21 75.16 85.70 58.42 443.85 85.0 29.72 42.68 47.47 51.74 58.20 65.47 72.03 77.19 80.21 82.68 88.67 62.49 501.72 87.5 35.08 48.10 52.63 55.72 63.10 71.78 77.01 83.17 85.35 87.96 92.55 67.08 494.14 90.0 43.90 58.12 61.52 63.88 74.91 79.58 84.70 88.73 91.11 93.39 97.52 74.29 460.04 92.5 46.04 65.73 70.87 76.46 81.96 88.09 90.97 92.96 94.29 95.52 98.86 79.50 434.87 95.0 53.03 71.50 76.15 80.49 87.94 92.23 94.22 95.93 96.47 97.03 98.61 83.57 348.34 97.5 83.25 92.94 94.71 96.00 97.50 98.67 99.50 100.00 100.00 100.00 100.00 94.16 138.63 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 0 to 6 hours 2.5 0 0 0 0 0 0 0 0 0 0 4.96 1.50 25.22 

5.0 1.90 3.95 4.29 5.32 8.94 12.61 17.78 20.13 21.05 25.00 35.25 15.27 162.99 7.5 2.25 5.15 6.28 8.49 10.84 14.75 17.59 22.62 28.46 31.95 41.99 18.60 239.09 

10.0 4.31 6.67 8.94 12.43 16.72 20.25 26.52 33.33 37.02 42.56 53.93 25.06 347.40 12.5 3.59 12.01 14.31 16.67 22.38 29.31 34.69 37.93 40.78 49.66 61.44 30.89 437.86 15.0 7.51 16.80 18.92 21.56 32.60 35.98 39.47 48.65 52.10 57.88 69.52 37.35 473.89 17.5 9.71 16.67 17.83 20.76 26.83 39.47 47.93 60.38 63.44 66.65 72.84 40.62 605.79 20.0 11.93 19.39 21.87 24.67 31.92 42.75 53.43 63.05 66.26 70.22 81.71 44.15 671.47 22.5 6.55 16.90 18.67 23.40 33.12 43.29 59.97 67.73 74.93 75.86 86.27 46.12 859.12 25.0 8.11 21.62 25.26 32.10 39.31 45.65 58.93 70.97 76.02 78.10 85.20 48.80 768.09 27.5 10.65 23.29 24.68 29.36 41.73 52.06 59.44 67.44 70.14 74.38 83.96 48.85 680.62 30.0 16.79 29.86 34.31 40.00 53.36 60.31 70.15 76.66 82.63 84.35 87.95 56.85 722.60 32.5 14.86 28.33 33.10 36.64 47.55 55.26 67.13 74.84 79.19 82.68 87.94 54.49 713.40 35.0 15.54 42.11 50.33 54.14 61.10 66.87 77.66 84.07 86.81 87.85 92.76 63.85 692.98 37.5 22.73 33.19 37.43 40.02 49.34 62.70 67.97 81.20 84.83 87.80 91.76 59.19 698.98 40.0 26.22 43.32 51.41 57.14 67.13 75.81 81.14 86.28 88.25 89.12 93.33 66.76 710.63 42.5 25.00 38.98 49.08 54.20 64.85 71.18 78.00 87.25 88.75 89.34 94.83 65.97 659.86 45.0 20.99 39.30 47.06 61.32 72.80 78.30 80.46 84.98 89.06 90.63 93.81 67.66 711.40 47.5 21.41 36.67 47.72 58.90 65.25 79.25 82.99 88.16 89.15 90.05 94.86 67.20 727.65 50.0 31.24 44.17 54.01 57.27 69.42 73.91 82.49 86.90 89.70 91.04 94.02 69.03 583.27 52.5 25.35 44.89 54.06 59.28 69.42 78.50 82.80 87.52 90.38 92.36 96.31 69.10 696.20 55.0 41.91 56.28 59.32 62.99 73.86 83.90 87.94 90.97 92.78 93.87 96.20 74.44 497.31 57.5 40.66 55.61 61.79 67.36 75.19 81.67 85.00 87.98 90.58 92.45 96.80 74.35 448.65 60.0 39.08 56.62 65.66 74.25 81.62 85.09 88.08 91.97 93.52 94.26 96.45 76.05 584.48 62.5 38.60 62.25 67.48 71.27 77.18 86.26 88.80 90.45 92.36 93.29 97.21 76.04 557.16 65.0 40.46 64.34 69.57 70.89 79.14 86.61 91.69 93.93 94.62 96.37 97.55 78.09 569.95 67.5 49.21 68.06 69.81 74.01 78.62 85.83 90.80 93.11 94.11 95.04 97.60 79.42 384.39 70.0 31.94 73.87 75.27 78.81 85.18 89.40 93.23 94.32 94.89 95.71 97.90 80.82 511.79 72.5 44.53 71.32 77.59 83.17 87.15 91.67 93.48 94.80 95.33 96.09 97.96 82.51 415.09 75.0 54.07 73.45 77.97 80.11 85.49 90.71 94.41 96.03 96.54 96.96 98.15 84.02 292.07 77.5 68.19 81.74 83.28 84.92 90.10 92.18 93.72 95.45 96.91 97.84 98.85 87.50 178.38 80.0 69.88 84.74 86.14 87.53 90.68 93.15 95.50 96.78 97.09 98.21 99.17 88.25 251.06 82.5 74.27 85.83 87.88 88.92 92.08 94.83 96.59 97.30 97.77 98.31 99.23 89.21 258.11 85.0 77.91 83.58 90.00 93.12 95.12 96.66 97.87 98.23 98.49 98.70 99.10 91.19 215.31 87.5 83.63 90.61 92.85 94.44 95.21 96.70 98.19 98.58 98.72 98.91 99.40 92.46 174.85 90.0 87.30 91.96 92.50 94.56 95.92 96.96 98.25 98.84 99.07 99.16 99.62 93.97 97.40 92.5 90.42 94.25 95.66 96.71 97.50 98.41 98.64 99.17 99.44 99.67 100.00 95.61 66.08 95.0 89.14 95.74 96.63 97.35 97.89 98.50 99.09 99.26 99.35 99.51 100.00 96.95 18.60 97.5 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.89 .63 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 6 to 12 hours

2.5 0 0 0 0 0 0 1.44 3.80 5.69 8.21 17.69 4.85 77.39 5.0 2.36 3.54 4.56 5.84 8.54 13.14 19.42 24.22 26.68 30.70 44.49 18.57 300.75 7.5 3.15 6.00 8.62 11.13 15.83 22.59 27.72 32.91 37.71 43.39 54.79 25.86 427.45 

10.0 4.26 8.83 10.95 13.65 20.98 26.85 33.77 40.46 47.22 54.05 73.21 32.07 606.51 12.5 4.86 10.47 12.22 14.79 21.19 30.76 36.03 44.87 53.37 58.74 79.27 34.55 693.79 15.0 5.40 14.91 17.40 20.50 29.50 34.24 41.65 49.83 56.84 61.71 81.24 38.96 683.04 17.5 7.40 12.49 16.50 20.46 28.00 37.85 46.37 53.64 60.62 63.76 82.38 40.17 716.66 20.0 9.94 16.34 20.45 24.28 31.08 39.40 46.01 61.91 66.84 70.19 86.05 43.75 753.87 22.5 6.78 14.29 15.94 18.56 29.31 39.90 50.21 61.06 66.99 72.61 83.76 42.74 810.22 25.0 10.07 20.85 27.25 30.16 37.32 44.41 54.71 62.19 69.55 73.85 85.39 46.72 723.81 27.5 11.42 19.52 22.37 30.52 35.65 44.84 58.45 65.93 70.69 78.26 88.63 48.17 782.65 30.0 13.02 23.51 31.59 32.62 41.42 48.87 62.07 72.41 75.06 81.94 88.62 51.54 760.93 32.5 11.50 20.54 25.80 32.45 39.15 46.45 60.07 73.01 78.39 81.81 88.47 50.24 834.04 35.0 13.85 26.38 30.24 33.83 42.78 49.32 62.36 74.40 80.10 82.77 89.27 52.84 767.51 37.5 13.00 20.12 26.12 31.57 43.34 47.95 65.72 77.70 83.10 86.35 90.23 52.61 872.90 40.0 17.69 30.49 32.20 35.63 45.53 53.03 66.84 78.52 82.17 85.57 91.20 55.65 763.98 42.5 15.76 28.86 33.24 39.35 47.85 54.72 68.93 76.17 81.74 86.37 91.41 56.40 766.34 45.0 9.42 18.81 24.92 32.78 41.91 57.68 69.51 79.43 81.79 85.24 91.28 53.84 924.54 47.5 12.62 22.96 27.62 33.07 43.84 55.41 66.41 79.81 83.03 87.50 92.92 55.05 905.26 50.0 15.11 29.02 33.88 42.32 54.25 67.26 76.25 80.86 83.16 85.87 92.96 59.80 797.72 52.5 11.93 25.99 29.84 33.59 49.62 58.38 70.85 80.76 83.09 87.13 95.05 56.93 914.08 55.0 25.33 31.59 35.24 41.46 51.77 66.04 75.38 82.44 84.00 86.56 93.26 60.52 725.40 57.5 15.16 31.21 35.80 39.42 49.76 62.01 74.67 82.78 84.31 86.93 92.97 58.78 840.23 60.0 17.08 32.25 36.34 42.99 54.49 63.04 73.90 83.58 84.99 87.91 92.79 60.28 770.27 62.5 26.92 36.19 40.11 47.73 59.07 71.70 79.82 86.35 87.61 89.97 96.15 64.36 716.69 65.0 25.10 44.00 51.33 59.99 69.19 76.51 80.27 84.37 86.77 90.86 95.59 67.59 660.81 67.5 27.82 43.14 47.02 53.45 65.72 74.94 80.87 86.53 88.92 90.91 96.15 67.26 653.69 70.0 22.04 43.25 48.31 52.99 62.52 73.35 81.89 85.80 89.01 90.72 96.76 66.36 722.97 72.5 29.79 49.43 54.96 61.44 69.10 81.53 84.25 89.28 90.21 92.55 96.29 70.74 615.76 75.0 33.33 50.65 56.44 66.20 73.71 81.66 86.14 89.33 91.47 92.61 97.76 72.28 614.43 77.5 38.95 53.62 57.17 63.81 77.60 84.17 88.81 91.76 93.06 93.66 97.17 74.74 528.83 80.0 44.98 54.30 61.33 67.37 75.21 83.55 87.74 91.62 93.05 94.22 97.20 75.75 477.23 82.5 50.14 61.69 69.50 74.98 82.51 88.30 90.62 93.04 94.44 95.66 98.25 79.65 401.97 85.0 52.73 72.69 79.21 80.99 87.76 90.97 92.96 95.31 95.91 97.19 98.57 83.41 350.98 87.5 61.94 81.24 83.93 86.33 89.93 92.89 94.56 95.86 97.08 97.49 98.79 86.71 263.79 90.0 59.46 84.78 88.25 90.06 93.25 94.67 96.06 97.52 97.84 98.13 98.96 87.81 314.21 92.5 73.58 88.67 91.25 92.59 94.48 95.94 97.09 97.99 98.29 98.64 99.54 90.61 210.21 95.0 81.94 92.41 94.49 95.82 96.75 97.54 98.12 98.68 99.06 99.25 99.98 93.06 173.44 97.5 96.78 98.82 99.28 99.71 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.15 51.68 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 12 to 24 hours 2.5 0 0 0 0 0 1.45 3.51 5.74 7.83 10.53 18.75 6.22 109.18 

5.0 2.12 4.41 6.18 7.62 11.90 16.74 19.95 24.65 28.31 33.60 48.55 20.60 353.23 7.5 4.57 7.96 9.40 11.82 19.85 25.94 30.50 36.94 41.52 46.74 58.94 28.45 453.95 

10.0 6.76 10.70 13.38 17.14 25.37 34.20 38.32 47.20 51.37 56.58 69.79 35.21 572.32 12.5 8.83 15.44 19.25 21.92 33.33 39.45 44.06 51.94 58.46 65.07 78.32 40.80 648.71 15.0 10.06 18.68 21.85 26.11 37.13 44.28 50.44 55.14 61.83 68.41 82.01 44.17 678.12 17.5 8.89 19.75 25.81 32.60 41.30 49.78 54.61 59.05 63.54 69.92 81.82 46.81 681.01 20.0 9.06 20.70 25.10 38.00 46.74 52.30 58.25 63.08 68.75 74.17 83.51 49.29 699.32 22.5 12.30 22.80 29.25 38.00 51.62 56.07 62.86 67.19 70.80 77.53 86.20 52.21 698.50 25.0 13.48 20.87 25.67 33.21 45.58 56.62 67.78 71.98 74.30 77.32 86.83 52.29 762.24 27.5 13.24 25.69 31.71 37.41 52.36 59.97 71.88 79.34 80.50 82.26 87.52 55.73 791.17 30.0 15.31 27.60 36.29 43.97 53.68 66.18 78.17 82.59 83.91 85.39 89.85 58.97 814.57 32.5 14.15 26.90 32.20 39.46 53.20 60.31 75.09 85.62 87.46 89.44 92.28 58.59 880.47 35.0 13.34 28.57 38.13 44.78 56.92 64.46 74.90 88.31 91.06 93.29 95.41 61.29 907.97 37.5 13.51 26.94 32.33 40.15 53.56 61.47 74.57 81.95 87.91 90.82 95.79 59.11 900.15 40.0 14.47 27.88 34.29 39.96 50.88 59.91 70.73 81.85 86.79 90.62 96.06 58.47 870.24 42.5 14.64 29.72 35.48 42.63 52.43 61.61 71.96 81.25 88.04 92.69 95.97 59.71 871.82 45.0 19.11 33.51 40.40 46.51 55.27 66.26 75.84 82.80 88.65 92.31 96.42 62.11 811.09 47.5 19.00 33.27 39.91 46.26 54.95 65.65 76.07 83.85 89.49 92.86 96.93 62.10 819.34 50.0 19.65 35.11 39.81 44.99 54.88 66.60 73.16 81.26 85.86 90.49 96.51 61.40 762.77 52.5 20.18 32.37 41.39 47.47 56.03 67.46 78.57 86.62 90.68 93.54 97.19 63.19 826.14 55.0 20.66 35.83 42.61 46.12 57.25 66.30 76.34 83.39 87.35 90.57 95.66 62.59 744.75 57.5 25.32 42.70 47.51 51.83 60.57 67.17 76.34 87.03 90.34 92.11 97.00 65.47 667.98 60.0 23.10 41.38 48.43 55.38 66.23 73.67 83.38 89.96 92.16 93.66 97.30 68.17 730.74 62.5 31.30 48.94 54.23 59.16 66.67 76.57 83.28 90.55 93.10 94.59 97.91 70.62 597.45 65.0 32.49 53.28 59.45 63.75 72.58 80.66 85.79 91.29 93.96 95.03 98.30 72.90 603.82 67.5 38.31 51.92 58.19 64.94 74.18 81.00 86.22 92.29 94.13 95.59 98.62 74.14 544.31 70.0 36.87 47.67 57.56 61.51 72.63 78.88 85.13 90.78 93.65 94.83 98.03 72.64 569.65 72.5 39.84 51.99 57.69 63.46 72.86 81.58 86.57 93.31 95.08 96.27 98.67 74.07 552.87 75.0 42.05 55.13 60.15 65.37 76.92 82.57 87.92 93.36 94.96 96.90 99.02 75.73 524.71 77.5 45.84 61.19 66.15 71.84 79.96 85.61 89.70 93.94 95.42 97.11 98.72 78.34 444.06 80.0 48.86 61.59 67.69 71.83 80.24 86.53 90.44 93.86 95.61 96.69 98.67 78.92 441.62 82.5 51.35 67.50 71.95 76.27 84.26 88.22 92.00 95.11 96.73 97.33 99.03 81.05 415.64 85.0 43.90 69.04 72.36 76.17 82.27 87.84 92.31 95.36 96.23 97.51 98.74 80.21 450.15 87.5 52.48 72.68 77.99 81.77 88.02 90.21 93.89 96.92 97.46 98.28 99.52 83.41 395.82 90.0 62.71 79.52 82.53 84.92 90.13 92.19 95.50 97.42 98.05 98.40 99.50 86.33 325.82 92.5 69.54 84.86 87.39 89.34 92.01 93.07 94.92 97.49 98.24 98.68 99.50 87.75 337.68 95.0 63.10 85.51 89.53 92.23 94.27 95.52 97.05 98.12 98.70 99.17 99.78 89.15 292.43 97.5 90.99 96.85 97.67 98.38 99.63 100.00 100.00 100.00 100.00 100.00 100.00 96.58 88.44 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 24 to 72 hours

2.5 0 0 0 0 1.40 3.40 5.76 9.07 11.91 15.76 28.11 9.32 219.95 5.0 2.48 5.17 6.10 7.87 11.39 15.82 22.20 29.36 33.86 39.82 50.40 22.47 423.32 7.5 3.86 7.37 9.76 11.54 16.23 22.80 31.22 37.85 42.77 48.66 59.61 28.02 495.92 

10.0 5.36 10.11 11.79 14.69 19.44 27.97 35.59 48.94 54.68 60.26 70.31 34.06 666.75 12.5 4.89 10.03 11.92 15.36 21.31 31.38 42.03 57.20 64.98 71.38 81.37 38.39 851.04 15.0 7.12 11.71 13.64 17.00 24.21 32.11 44.07 55.57 61.30 69.98 83.20 39.47 814.76 17.5 6.55 12.55 15.23 18.05 25.90 32.29 43.88 56.11 64.34 71.71 85.05 40.43 838.24 20.0 6.06 13.09 16.86 20.87 27.75 35.52 49.25 61.70 69.13 76.92 86.77 42.60 876.27 22.5 4.97 12.23 16.34 19.96 28.15 36.49 46.93 61.02 66.87 75.47 87.24 42.44 889.18 25.0 7.96 12.36 16.87 21.46 28.02 36.70 51.47 61.41 69.21 75.66 86.96 43.39 889.88 27.5 10.53 14.88 18.34 22.39 30.73 35.50 48.25 61.12 68.73 75.67 87.83 43.79 843.08 30.0 11.13 19.50 23.42 28.38 33.01 38.11 49.50 60.64 64.34 70.68 88.53 45.09 754.62 32.5 10.90 17.25 20.33 24.09 34.10 39.16 47.31 55.87 59.89 66.34 84.56 43.09 692.19 35.0 11.42 20.85 25.45 30.14 37.91 44.69 56.09 62.25 64.01 70.97 88.33 47.22 709.58 37.5 12.92 21.53 25.52 29.64 39.29 49.71 59.68 65.26 66.85 70.12 81.29 48.35 670.89 40.0 13.89 22.48 26.02 30.43 39.25 47.24 59.06 67.40 69.33 73.58 82.57 48.82 677.84 42.5 19.32 27.88 29.87 32.47 40.44 46.47 60.09 69.73 71.68 76.49 85.76 51.33 635.06 45.0 17.56 26.99 33.12 37.20 43.99 50.10 61.14 71.58 76.45 80.11 94.52 53.42 736.23 47.5 12.29 21.37 29.26 35.09 43.73 51.53 58.87 69.95 73.83 80.45 88.87 51.14 768.58 50.0 16.30 23.46 29.48 34.41 44.69 56.22 63.41 73.32 77.39 82.18 91.59 54.00 777.11 52.5 21.02 31.13 35.24 38.87 44.57 55.01 62.45 69.63 73.62 77.94 88.89 54.22 648.86 55.0 27.61 39.98 43.52 45.55 49.87 57.64 64.35 74.69 78.57 82.64 90.53 58.67 569.19 57.5 22.82 41.04 46.96 49.37 57.63 63.47 72.09 79.12 81.84 84.58 92.12 61.44 625.80 60.0 28.55 42.43 44.83 48.58 53.13 62.90 72.81 81.11 84.14 86.57 93.96 62.60 585.33 62.5 29.46 44.71 50.93 53.48 60.24 67.06 74.55 83.77 86.74 90.71 95.27 65.36 588.59 65.0 22.51 38.85 45.25 49.33 58.10 66.67 75.21 80.62 86.74 90.38 97.17 63.48 682.69 67.5 26.87 42.58 46.58 53.02 59.75 68.11 76.14 82.33 86.52 88.93 96.71 64.97 611.63 70.0 33.69 45.39 49.10 56.89 63.75 71.78 79.49 89.01 90.79 93.95 98.54 68.81 610.07 72.5 30.21 46.24 50.28 55.45 67.79 76.89 82.28 89.19 91.44 94.09 97.88 69.88 618.77 75.0 34.10 46.01 51.70 56.63 62.55 71.65 80.00 86.85 90.98 94.12 98.54 69.03 576.96 77.5 35.05 51.84 56.38 61.51 66.95 76.08 83.89 89.19 92.70 94.95 97.97 70.91 606.02 80.0 35.20 49.41 57.87 61.08 66.10 73.98 79.81 87.00 89.99 93.31 97.78 70.10 548.15 82.5 44.32 54.88 59.76 64.53 71.25 78.57 84.09 89.52 93.37 94.84 97.99 74.08 450.42 85.0 52.30 63.34 68.31 71.41 77.40 83.09 87.94 91.87 94.30 96.32 98.38 78.32 380.60 87.5 53.94 66.72 72.36 75.32 80.39 85.03 88.70 94.19 95.25 96.71 98.43 80.06 355.19 90.0 56.00 66.10 72.11 76.99 82.69 85.71 89.14 94.46 96.69 97.54 98.95 81.49 302.05 92.5 68.27 78.13 81.61 84.12 88.25 90.63 93.63 96.37 97.38 98.30 99.20 87.20 165.88 95.0 76.86 84.91 87.40 89.71 92.79 94.84 96.18 97.59 98.25 98.80 99.56 90.91 114.82 97.5 90.46 95.11 96.32 97.32 98.53 99.42 100.00 100.00 100.00 100.00 100.00 96.90 32.65 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 0 to 72 hours 2.5 0 0 0 0 0 1.15 3.36 6.13 7.98 11.03 21.27 6.71 144.22 

5.0 2.29 4.42 5.94 7.28 10.99 15.57 20.20 25.34 29.61 34.68 47.87 20.74 366.21 7.5 3.94 7.29 9.03 11.32 16.30 23.46 29.08 35.57 40.51 45.62 58.22 27.20 457.05 

10.0 5.42 9.69 12.04 14.99 21.10 29.63 36.33 45.11 51.21 56.01 69.00 33.37 599.11 12.5 6.17 11.90 14.89 18.23 25.24 34.34 41.56 51.79 58.41 65.18 79.58 38.18 721.36 15.0 7.88 14.25 17.82 21.83 30.71 38.51 46.44 54.18 59.57 67.00 81.82 41.14 719.34 17.5 7.89 14.71 18.99 23.56 32.25 41.98 50.92 58.46 62.89 69.01 81.94 42.95 743.48 20.0 8.81 16.34 21.18 25.00 34.56 45.76 54.34 62.32 67.36 73.83 84.19 45.59 774.45 22.5 7.14 16.13 20.48 24.81 36.39 47.95 57.29 65.61 69.60 75.75 85.94 46.70 818.76 25.0 9.28 18.42 22.09 26.99 37.08 48.71 58.75 69.75 72.84 76.75 86.22 48.06 813.28 27.5 11.47 20.00 24.17 29.94 37.27 50.36 60.46 71.28 77.28 80.05 87.50 49.66 822.18 30.0 13.56 23.57 29.47 32.84 41.30 53.13 62.92 74.66 81.01 83.77 88.77 52.58 811.41 32.5 11.77 21.15 26.87 32.56 40.31 50.67 59.35 72.31 77.82 83.78 90.70 51.31 829.90 35.0 12.50 24.92 30.29 36.97 45.18 56.51 63.35 74.24 80.67 86.85 93.97 54.55 834.32 37.5 13.60 24.84 28.37 33.87 45.18 55.49 65.21 74.19 78.48 83.80 92.42 54.06 814.75 40.0 14.57 26.89 31.61 36.58 46.33 57.23 66.94 75.49 79.66 84.95 93.15 55.29 797.46 42.5 18.73 28.92 32.81 37.81 46.58 57.96 68.43 76.34 79.73 86.18 94.09 56.61 764.96 45.0 16.49 30.16 35.50 40.28 50.02 60.90 71.73 79.51 82.27 87.87 94.95 58.24 817.21 47.5 14.29 26.40 33.94 39.45 50.06 59.56 68.82 79.16 82.98 87.40 95.04 57.26 839.22 50.0 18.41 30.69 36.65 41.83 53.28 63.25 71.82 79.47 83.52 87.24 94.87 59.33 774.63 52.5 20.15 31.09 37.08 41.80 52.60 61.48 71.35 80.57 84.21 88.52 96.15 59.36 789.13 55.0 25.00 38.74 43.16 46.98 55.60 63.41 73.48 81.34 84.95 88.45 94.34 62.02 668.57 57.5 24.22 40.19 45.45 49.53 59.29 67.16 75.08 83.08 85.58 89.14 95.31 63.50 676.86 60.0 25.74 41.77 45.90 50.01 61.70 70.62 79.65 85.51 88.77 91.35 95.93 65.53 686.50 62.5 29.84 45.26 51.53 56.30 63.54 72.36 79.82 87.48 89.82 92.50 96.59 67.98 622.56 65.0 26.76 44.27 51.40 57.76 66.69 74.53 80.79 87.43 90.86 93.52 97.39 68.37 668.20 67.5 33.47 47.03 53.14 58.21 68.58 76.39 82.24 88.29 91.51 93.52 97.38 70.16 596.28 70.0 33.62 46.88 53.76 60.00 69.29 77.39 83.87 89.19 92.40 94.33 97.96 70.63 625.41 72.5 33.17 49.89 55.46 61.47 72.70 81.05 86.16 90.87 93.50 95.12 97.98 72.61 591.09 75.0 35.87 51.77 56.86 61.19 71.84 79.93 85.35 90.88 93.40 95.65 98.31 73.01 562.22 77.5 39.80 56.16 61.78 65.63 76.30 83.76 88.42 92.69 94.00 95.93 98.46 75.58 523.05 80.0 41.87 58.31 62.46 66.10 74.82 82.61 87.58 92.12 93.95 95.88 98.33 75.59 503.69 82.5 48.72 61.63 67.24 71.47 80.00 85.71 89.99 93.85 95.49 96.87 98.54 78.69 433.57 85.0 51.40 67.52 72.20 76.27 82.09 87.71 91.66 94.91 96.12 97.28 98.67 80.71 398.15 87.5 54.71 72.40 76.49 80.41 86.02 89.69 93.28 95.68 97.12 97.77 99.15 83.17 353.09 90.0 60.25 76.27 80.24 83.03 87.55 91.57 94.85 97.08 97.75 98.22 99.25 85.20 308.54 92.5 70.82 82.68 85.93 88.27 91.36 93.51 95.69 97.53 98.23 98.67 99.51 88.56 225.66 95.0 75.25 87.08 89.51 91.73 94.28 95.79 97.23 98.21 98.67 99.10 99.67 90.87 184.49 97.5 92.49 97.04 97.98 98.69 99.65 100.00 100.00 100.00 100.00 100.00 100.00 97.36 51.06 

Supplement 2. Untrimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th

First-quartile storms; storm duration 0 to 6 hours

2.5 0 0 0 0 0 0 0 0 0 3.80 8.22 2.71 53.08 5.0 4.07 7.14 9.02 10.34 14.31 18.28 20.31 23.61 25.69 31.61 39.89 19.85 192.88 7.5 5.05 10.00 11.40 14.23 16.35 19.32 26.17 32.59 35.21 38.70 55.00 24.51 285.13 

10.0 11.58 19.16 21.37 23.86 28.48 33.33 37.40 45.73 47.52 53.19 62.60 35.44 332.84 12.5 14.51 23.42 27.60 29.50 34.63 36.54 40.66 51.59 59.59 61.26 68.24 40.98 395.92 15.0 18.98 30.61 33.86 35.84 38.76 42.94 50.38 59.43 61.65 65.56 74.59 46.48 409.83 17.5 19.65 33.13 38.87 41.37 47.83 54.88 63.08 67.43 71.44 72.56 77.68 52.83 465.06 20.0 32.17 46.53 51.32 52.45 58.62 63.46 67.34 73.70 76.37 80.33 83.95 61.28 387.23 22.5 36.77 46.22 52.95 59.18 63.49 69.60 75.60 78.69 81.48 84.83 90.54 66.48 385.12 25.0 37.75 45.21 50.16 56.14 62.89 70.98 77.07 78.63 81.48 83.01 88.84 65.71 407.19 27.5 46.93 53.62 58.21 59.93 63.56 68.37 73.94 78.91 79.65 82.47 89.69 67.91 271.39 30.0 53.49 60.89 63.76 69.30 74.32 76.96 82.40 85.36 85.93 86.71 91.42 75.06 204.92 32.5 44.55 55.46 63.20 68.03 72.02 77.60 81.38 84.21 85.85 87.71 91.88 71.75 394.10 35.0 56.88 61.54 65.26 66.49 76.80 80.21 86.08 87.52 88.22 90.06 95.64 77.58 201.15 37.5 44.56 62.76 65.83 70.23 78.04 83.75 87.14 89.51 90.71 92.30 94.77 76.22 434.73 40.0 69.88 78.49 79.76 80.34 82.21 85.45 88.55 91.88 92.81 93.10 94.93 84.23 101.82 42.5 57.46 67.05 70.31 76.08 80.17 85.51 88.80 89.99 92.74 93.71 96.54 80.34 254.88 45.0 49.99 68.74 75.80 79.12 81.05 86.42 90.53 92.14 92.91 94.00 97.09 81.13 276.21 47.5 73.61 80.17 80.88 82.41 84.86 88.35 89.35 90.97 91.77 94.26 97.13 86.15 76.05 50.0 66.12 71.81 74.98 76.86 85.00 87.20 90.88 93.52 93.80 94.16 96.01 83.21 188.36 52.5 68.15 77.34 79.97 81.43 82.99 88.01 91.26 93.01 93.98 96.09 98.24 84.01 274.06 55.0 71.23 77.97 81.14 83.92 87.08 91.45 93.55 94.26 96.00 96.53 98.84 86.50 182.96 57.5 72.04 78.07 81.07 83.90 85.65 87.88 91.35 93.90 94.50 95.69 98.53 85.90 150.88 60.0 75.09 83.37 86.91 87.93 91.69 93.58 94.26 95.50 95.96 96.68 98.35 88.36 243.56 62.5 70.38 81.20 87.73 88.46 88.98 92.30 93.24 94.56 96.21 97.10 99.53 87.69 226.01 65.0 86.23 89.79 90.00 91.84 93.72 94.56 96.35 96.74 97.00 97.74 99.34 93.91 17.98 67.5 67.24 73.70 77.54 80.34 88.75 91.75 93.63 95.02 96.22 96.93 98.40 85.27 255.08 70.0 79.55 88.89 91.76 93.16 93.91 94.38 95.28 95.83 96.79 97.57 98.75 92.67 43.37 72.5 76.52 89.85 91.04 91.91 93.91 94.78 95.30 96.88 97.54 97.82 99.20 90.48 173.06 75.0 73.47 80.00 90.32 92.20 94.62 95.80 96.50 96.61 97.08 97.40 99.76 90.70 126.93 77.5 78.20 89.11 90.73 92.61 93.72 94.85 96.00 97.86 98.21 98.53 99.31 91.70 117.63 80.0 82.56 91.81 93.93 95.12 95.72 96.97 97.33 98.38 98.74 99.09 99.61 94.25 53.16 82.5 85.36 90.06 92.25 94.83 96.38 96.91 97.51 98.30 98.42 98.65 100.00 93.21 117.05 85.0 81.34 87.01 94.81 95.13 96.38 97.02 97.82 98.57 98.73 98.98 99.92 94.33 45.88 87.5 91.56 94.71 96.36 96.50 97.58 98.13 98.57 98.87 98.93 99.24 99.94 97.04 8.64 90.0 88.78 94.02 94.79 95.66 96.63 98.26 98.86 99.15 99.19 99.25 100.00 96.54 13.63 92.5 93.30 96.33 97.46 97.51 98.58 98.78 99.37 99.76 100.00 100.00 100.00 97.22 35.51 95.0 90.01 96.11 97.15 97.26 97.44 98.27 98.71 99.12 99.14 99.50 100.00 97.17 13.10 97.5 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.98 .01 
First-quartile storms; storm duration 6 to 12 hours 2.5 0 0 0 0 0 1.15 4.49 8.06 11.62 13.57 23.95 7.15 114.25 

5.0 4.95 8.34 10.23 13.58 18.50 21.81 27.11 33.01 40.14 44.00 53.46 26.40 360.89 7.5 10.73 15.84 18.47 21.24 27.63 30.44 35.85 43.42 49.59 52.96 65.88 34.48 413.71 

10.0 13.25 22.61 26.07 28.31 35.18 40.45 51.87 57.25 61.75 67.96 82.55 44.63 573.68 12.5 15.18 26.45 31.36 32.67 37.63 44.42 53.80 62.19 68.23 77.72 86.36 48.65 629.79 15.0 21.75 33.66 37.97 39.73 45.28 51.50 58.93 66.26 71.07 78.41 88.46 54.21 538.94 17.5 23.42 36.49 41.22 43.72 48.44 53.35 59.85 64.98 71.03 75.16 87.76 54.91 500.08 20.0 30.66 42.18 45.58 48.54 59.08 65.33 69.13 74.00 79.62 85.06 95.48 62.52 529.31 22.5 27.45 41.66 45.83 48.50 55.95 62.91 70.58 76.00 80.07 82.68 94.04 61.46 543.30 25.0 33.63 50.21 53.37 55.88 59.91 67.22 72.94 77.51 81.88 83.27 89.12 65.07 435.93 27.5 46.97 53.90 55.69 59.72 65.03 69.05 74.08 82.28 85.45 87.62 95.56 69.37 382.29 30.0 46.07 52.13 55.56 59.90 67.07 73.07 76.53 84.00 86.05 88.35 94.52 69.94 395.48 32.5 48.28 55.96 60.75 66.06 73.01 76.91 81.39 83.28 85.41 86.27 91.87 72.84 305.37 35.0 50.84 57.81 63.31 66.43 73.90 79.12 81.67 85.22 86.42 87.71 96.92 73.95 361.17 37.5 52.52 65.62 67.48 70.14 77.11 81.70 84.77 87.29 88.09 89.72 95.46 76.75 307.89 40.0 53.76 59.46 69.01 72.31 76.99 81.13 84.87 89.57 90.07 91.20 96.88 78.38 224.13 42.5 59.88 68.83 71.60 73.41 77.44 81.74 85.41 89.70 91.09 91.31 95.34 79.48 191.28 45.0 59.26 69.75 74.60 76.72 78.85 82.97 85.96 90.10 91.22 91.71 97.27 80.37 212.47 47.5 54.20 66.50 75.37 77.50 81.04 84.58 89.82 92.08 92.44 93.03 97.27 79.68 370.48 50.0 54.28 62.96 70.61 75.05 78.99 80.91 84.00 89.04 89.89 91.69 95.24 77.13 379.90 52.5 53.79 75.01 77.79 78.56 82.71 85.30 89.69 92.22 94.26 96.30 98.83 80.98 427.91 55.0 50.80 67.04 74.61 77.28 80.66 83.46 87.33 91.93 92.68 94.99 98.07 78.90 403.09 57.5 54.20 75.42 79.84 80.83 83.78 86.50 88.67 91.01 92.86 97.59 98.92 81.54 395.55 60.0 62.17 72.54 81.37 82.70 83.84 85.71 90.12 92.81 94.83 95.45 98.25 83.68 203.78 62.5 51.50 76.37 78.14 82.35 85.74 89.47 92.44 95.17 96.50 97.98 99.25 83.55 354.98 65.0 70.71 77.20 79.38 81.44 82.71 85.33 90.25 93.22 96.23 98.95 100.00 84.74 230.23 67.5 54.68 74.93 77.24 79.79 84.14 86.45 89.89 93.15 96.04 96.73 98.94 82.28 320.71 70.0 53.67 71.00 79.02 82.26 84.35 89.74 91.92 95.19 96.88 97.66 100.00 82.93 379.07 72.5 63.05 80.44 82.19 83.67 87.25 89.59 93.00 94.77 97.32 98.17 99.51 86.05 239.21 75.0 71.43 80.89 82.40 85.25 87.85 90.67 93.23 97.74 98.42 99.27 100.00 86.83 254.10 77.5 55.50 78.54 82.71 83.59 86.58 89.70 92.81 94.22 97.09 98.26 99.36 84.55 312.04 80.0 61.97 82.71 83.94 87.39 91.02 92.24 94.23 96.14 97.60 98.69 100.00 85.50 414.31 82.5 45.94 77.72 81.88 83.36 90.34 92.63 94.56 97.07 98.42 98.53 99.75 84.33 433.81 85.0 52.47 81.15 82.05 86.41 90.96 94.55 96.04 98.07 98.55 98.80 99.57 86.45 335.48 87.5 69.58 86.36 88.50 89.50 94.26 95.57 97.17 98.05 98.85 99.12 100.00 90.11 228.03 90.0 72.33 88.21 89.07 91.76 93.89 95.57 97.67 98.37 98.51 98.91 100.00 91.14 166.90 92.5 84.11 89.62 91.47 92.83 94.78 96.42 97.35 98.32 98.62 98.98 99.51 93.32 74.36 95.0 90.12 93.41 95.24 95.81 97.47 98.03 98.58 99.15 99.32 99.60 100.00 96.09 30.19 97.5 98.09 99.62 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.21 7.46 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First-quartile storms; storm duration 12 to 24 hours

2.5 0 0 0 0.46 2.14 4.48 6.93 10.18 12.39 15.09 24.53 8.80 143.67 5.0 6.07 11.82 14.09 15.77 18.84 22.10 26.62 32.99 35.62 40.26 54.10 26.87 366.17 7.5 9.44 17.47 22.77 25.25 28.68 32.28 38.58 45.48 49.37 54.15 61.88 35.94 406.68 

10.0 15.10 24.21 29.56 32.70 36.50 41.58 50.00 55.75 60.99 64.71 73.75 44.59 478.22 12.5 20.06 27.01 33.77 38.05 41.65 45.37 52.31 62.23 67.27 74.45 82.38 49.61 537.22 15.0 25.03 33.25 39.91 42.97 48.89 52.30 56.84 67.62 73.81 78.79 86.52 54.69 497.47 17.5 32.88 42.20 47.11 50.08 53.50 56.55 61.73 69.50 76.43 80.11 86.87 58.77 433.12 20.0 43.75 49.40 51.39 52.47 57.19 59.66 64.26 74.10 77.49 80.38 88.68 62.79 331.79 22.5 48.46 52.43 53.44 56.09 61.61 65.26 68.56 75.25 79.19 80.93 88.49 65.60 294.77 25.0 49.46 54.17 57.81 61.55 68.91 71.47 74.29 78.16 80.25 83.52 90.02 69.29 284.10 27.5 48.05 55.64 58.89 63.46 73.26 78.08 80.19 82.32 83.50 85.34 90.57 71.73 311.77 30.0 48.94 58.53 63.80 68.80 78.47 82.05 83.51 85.43 86.30 87.87 92.39 74.47 345.25 32.5 48.93 56.18 60.05 68.43 76.69 84.46 87.42 90.16 90.83 91.56 93.56 75.51 410.25 35.0 50.62 58.83 61.29 69.61 77.03 87.23 90.83 93.52 94.12 94.96 95.99 77.73 433.33 37.5 50.71 57.75 61.18 64.98 75.44 82.00 89.00 92.07 93.95 95.14 96.78 76.55 422.21 40.0 49.80 58.32 61.06 64.50 75.12 79.83 87.66 92.21 93.70 95.83 97.52 75.86 457.54 42.5 53.34 59.27 62.04 67.46 75.83 83.09 91.42 94.16 94.89 95.51 97.72 78.57 327.87 45.0 58.54 64.46 70.50 73.69 79.89 86.71 91.56 94.79 96.15 96.45 98.11 81.95 231.57 47.5 53.16 60.61 66.99 71.72 78.11 83.77 90.19 93.66 94.57 96.15 97.87 79.56 307.33 50.0 56.72 67.22 71.44 74.29 80.80 86.43 90.80 94.50 95.32 96.26 98.22 81.37 298.01 52.5 59.81 67.59 73.00 79.85 86.47 90.94 94.00 95.87 96.26 96.77 98.77 84.38 238.43 55.0 59.67 71.22 74.30 78.58 82.77 89.10 91.67 94.36 96.05 96.89 98.09 83.54 227.05 57.5 60.47 65.01 69.77 73.11 80.45 90.03 91.97 94.72 96.39 97.25 98.23 82.80 233.71 60.0 60.78 71.68 74.07 82.94 88.38 92.16 94.11 95.71 96.41 97.25 98.75 85.32 221.61 62.5 61.33 70.00 73.47 78.45 82.97 87.32 92.35 94.46 95.24 97.63 98.98 83.64 207.17 65.0 68.38 73.93 79.23 81.25 84.05 91.80 94.21 96.15 96.57 97.07 99.17 86.26 155.61 67.5 63.49 76.89 81.62 84.04 87.87 93.31 94.75 96.65 97.28 98.11 99.70 87.27 169.45 70.0 61.19 70.55 73.90 76.41 82.07 86.99 91.65 94.54 95.13 97.29 99.76 83.11 240.55 72.5 61.24 69.23 74.40 78.75 85.91 92.92 95.90 97.35 97.99 98.65 100.00 85.69 219.07 75.0 63.99 71.20 74.34 77.54 81.75 88.86 92.62 95.15 96.51 98.01 99.72 84.63 179.51 77.5 65.63 73.42 78.33 81.64 88.32 90.90 94.30 97.05 97.47 98.17 99.10 86.24 207.81 80.0 68.12 75.00 78.76 82.61 88.14 92.45 95.10 96.22 97.12 97.70 98.84 87.08 162.80 82.5 68.35 77.78 81.04 84.11 91.27 93.95 95.94 97.33 97.81 98.28 99.59 88.60 147.55 85.0 72.36 79.62 81.22 82.40 85.17 90.84 94.70 96.32 97.18 97.91 98.51 88.13 97.68 87.5 80.30 86.98 88.02 88.62 90.22 93.69 95.39 97.41 97.93 98.62 99.44 91.44 63.48 90.0 84.94 90.91 91.56 91.73 93.58 96.79 97.70 98.18 98.56 99.10 99.54 93.96 42.91 92.5 83.03 91.00 92.19 92.19 93.01 94.40 96.36 97.91 98.26 98.54 99.32 93.29 45.07 95.0 84.88 89.43 91.53 93.75 94.79 95.60 97.36 98.23 98.71 98.98 99.77 93.13 98.65 97.5 93.68 97.50 98.19 99.13 100.00 100.00 100.00 100.00 100.00 100.00 100.00 97.70 38.43 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First-quartile storms; storm duration 24 to 72 hours 2.5 0 0 0.36 1.95 4.28 7.45 12.38 19.70 23.35 28.55 39.39 14.79 327.78 

5.0 7.44 11.84 14.46 16.97 21.49 26.18 35.84 42.95 45.65 49.79 62.15 32.20 500.00 7.5 11.60 21.24 23.33 25.20 31.47 36.42 42.77 50.37 52.84 59.39 70.05 39.85 524.75 

10.0 15.40 23.91 29.33 32.11 36.35 42.50 50.38 58.63 65.03 68.89 84.89 46.26 632.28 12.5 16.57 28.97 33.20 35.48 40.90 50.45 56.47 69.01 73.38 79.01 90.71 51.85 687.45 15.0 23.01 33.94 35.48 40.93 47.32 52.56 59.51 69.58 73.64 80.44 95.93 55.30 646.47 17.5 24.10 30.50 34.12 40.93 50.03 56.11 63.33 71.27 74.85 79.85 96.09 56.73 655.58 20.0 24.84 34.79 36.69 43.54 51.97 61.73 72.90 76.75 79.89 82.88 96.60 59.91 659.61 22.5 33.21 38.97 44.67 46.10 51.74 60.21 70.29 78.65 81.43 85.61 96.24 61.88 547.62 25.0 37.61 47.00 51.31 54.41 58.41 63.81 74.34 81.42 84.19 86.34 97.62 66.27 479.13 27.5 34.86 46.92 50.42 52.91 60.53 63.67 75.67 85.64 87.64 91.21 99.59 67.61 508.75 30.0 29.47 36.81 38.40 45.50 56.23 62.77 67.67 77.57 85.29 90.67 96.95 62.02 607.98 32.5 38.89 47.39 48.73 52.14 55.35 61.70 66.53 78.85 83.33 90.13 98.21 64.80 446.48 35.0 42.11 50.61 54.32 57.73 61.35 63.00 64.40 75.00 80.31 87.69 97.74 66.20 376.15 37.5 48.68 57.88 61.32 62.65 64.71 66.00 67.52 75.77 81.15 85.81 95.97 69.05 296.01 40.0 54.66 64.01 65.88 67.12 68.05 69.43 73.30 81.99 85.60 89.53 97.45 73.55 223.23 42.5 60.89 66.09 67.88 69.24 70.19 75.08 77.31 85.78 89.97 94.49 98.01 76.54 218.84 45.0 58.64 66.95 68.82 70.00 76.15 79.65 84.34 91.14 94.13 96.30 99.58 78.81 295.63 47.5 56.69 67.18 68.92 69.99 73.63 82.04 84.97 94.86 96.27 96.96 99.32 79.67 300.24 50.0 59.04 69.94 70.13 71.32 74.92 81.36 88.06 91.65 95.48 96.65 99.34 80.70 229.23 52.5 59.29 64.56 68.36 69.97 72.31 80.60 85.59 89.79 92.48 96.40 99.45 79.08 235.34 55.0 57.86 64.63 68.02 71.25 76.36 84.58 88.90 93.13 94.76 96.40 99.59 80.34 256.75 57.5 62.60 68.49 69.94 72.10 76.90 83.99 87.93 91.83 93.17 96.70 99.35 81.35 197.99 60.0 51.34 62.26 62.93 66.12 71.06 77.40 83.44 92.43 95.64 96.21 100.00 77.71 281.23 62.5 57.15 62.93 65.25 68.98 73.00 76.06 82.47 90.63 92.25 95.03 99.89 77.01 322.24 65.0 61.51 65.32 68.25 72.88 77.33 85.39 90.93 95.39 96.74 97.21 100.00 80.88 318.80 67.5 51.35 66.10 66.32 74.29 77.55 81.39 86.81 89.34 94.78 96.74 99.88 79.56 293.04 70.0 63.10 69.86 70.25 74.76 79.72 85.93 90.78 93.72 96.74 97.79 99.57 82.20 260.37 72.5 54.53 73.59 76.71 77.67 82.26 86.84 91.69 93.78 94.94 96.05 99.55 83.29 222.96 75.0 55.70 66.68 70.44 74.27 79.28 83.68 87.41 93.50 96.70 98.05 100.00 81.30 243.12 77.5 66.49 72.30 77.18 77.38 84.41 89.58 92.70 95.27 97.21 98.20 99.31 85.27 172.47 80.0 68.00 75.93 77.38 78.04 86.14 90.67 93.07 93.99 97.10 98.50 99.70 86.58 134.19 82.5 65.82 73.48 75.07 78.33 83.83 89.18 93.87 94.64 95.62 97.00 99.16 85.09 176.11 85.0 69.91 77.31 80.30 82.18 88.40 93.53 95.39 97.46 98.02 98.63 99.72 88.39 130.41 87.5 73.25 78.31 79.36 80.38 81.79 85.59 91.97 95.45 96.88 98.32 99.30 86.41 112.38 90.0 74.35 80.49 82.16 82.46 83.44 86.92 92.15 96.40 97.91 98.60 99.65 87.46 107.96 92.5 80.72 83.00 83.64 85.04 88.91 91.59 95.91 97.40 98.52 98.78 99.26 90.30 85.26 95.0 83.64 86.63 89.13 91.10 94.00 96.51 97.86 98.85 99.09 99.31 99.80 93.08 71.09 97.5 90.58 95.67 97.29 98.40 99.55 100.00 100.00 100.00 100.00 100.00 100.00 97.49 21.96 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First-quartile storms; storm duration 0 to 72 hours

2.5 0 0 0 0 1.01 3.86 6.66 10.75 13.29 17.13 29.28 9.59 198.02 5.0 6.04 10.98 13.41 15.33 19.01 22.53 27.45 34.91 39.52 44.76 55.17 27.80 402.30 7.5 9.49 16.54 20.47 23.58 28.07 32.28 37.81 45.61 50.00 53.70 64.09 35.78 443.84 

10.0 14.76 23.36 27.14 31.04 35.51 40.50 48.76 55.02 60.36 65.19 75.91 44.09 528.01 12.5 18.23 27.30 32.32 35.27 40.15 45.33 53.47 61.93 67.85 74.49 85.12 49.29 586.97 15.0 24.32 33.38 37.26 40.77 47.04 51.81 57.01 66.48 71.85 77.93 87.97 53.98 539.08 17.5 26.34 37.35 42.08 46.30 51.55 56.19 62.04 69.06 73.64 77.93 88.35 56.92 504.37 20.0 33.43 45.27 48.08 51.48 56.74 61.70 67.84 75.01 78.20 81.51 90.68 61.88 453.35 22.5 36.36 47.85 51.35 53.11 59.65 64.62 70.17 76.69 80.00 82.03 90.74 64.13 411.66 25.0 42.31 52.26 54.39 57.54 63.53 70.62 74.17 78.78 81.51 84.31 90.76 67.39 373.88 27.5 45.35 53.61 56.82 60.00 66.12 74.08 79.01 82.07 83.97 86.72 92.11 69.98 361.68 30.0 41.13 53.23 57.32 61.65 69.44 75.92 82.02 84.83 86.05 88.17 93.49 70.83 421.97 32.5 46.16 53.71 56.48 60.46 70.00 77.31 82.63 87.09 88.78 90.54 93.27 72.11 411.12 35.0 49.30 57.54 59.84 62.37 68.08 76.71 84.04 89.11 92.11 93.78 96.07 73.90 402.88 37.5 49.72 59.76 62.65 65.03 69.90 77.25 83.93 89.14 90.92 92.61 96.25 74.55 380.48 40.0 53.77 62.69 66.45 68.02 74.53 79.69 85.41 89.69 91.96 93.61 97.23 77.02 314.45 42.5 56.30 64.38 67.73 69.83 75.44 79.90 86.80 91.31 93.58 94.53 97.23 78.53 265.25 45.0 59.05 68.04 70.16 73.87 79.10 83.24 89.37 92.11 94.18 95.68 98.10 80.74 251.95 47.5 54.56 66.73 70.03 73.94 80.10 84.00 89.47 92.69 94.29 95.65 98.11 80.40 295.49 50.0 58.37 69.83 71.35 73.93 79.71 84.80 88.83 92.88 94.22 95.44 97.83 80.63 282.95 52.5 59.77 69.96 72.31 77.35 82.36 87.26 91.21 94.26 95.86 96.47 98.85 82.37 288.31 55.0 58.79 69.63 73.86 76.80 81.54 86.11 91.12 94.02 94.82 96.21 98.63 82.07 278.12 57.5 61.30 69.94 72.57 76.61 82.67 87.00 90.47 93.28 95.46 96.98 98.72 82.62 249.97 60.0 60.69 70.36 73.76 79.54 83.86 89.81 92.95 94.74 95.69 96.65 98.75 83.70 248.75 62.5 60.82 68.94 73.05 76.55 82.66 87.35 91.60 94.14 94.91 96.82 99.23 82.35 286.91 65.0 64.78 74.26 77.36 80.98 84.63 89.71 93.57 96.10 96.64 97.28 99.52 85.35 212.95 67.5 63.01 72.84 77.06 79.75 84.93 89.07 92.98 95.02 96.62 97.32 99.23 84.21 256.34 70.0 61.19 72.05 76.39 78.81 84.21 89.06 93.12 94.97 96.50 97.47 99.55 83.94 267.72 72.5 61.60 76.18 79.58 82.23 87.90 91.80 94.65 96.11 97.21 97.95 99.55 86.06 221.52 75.0 63.18 73.10 76.82 79.55 84.71 89.49 93.34 96.40 97.33 98.04 100.00 85.17 214.07 77.5 65.76 76.81 79.62 83.12 88.21 91.12 93.84 96.68 97.33 98.20 99.25 86.34 217.36 80.0 68.72 77.03 81.96 84.62 90.60 93.07 95.14 96.92 97.49 98.22 99.40 87.60 208.05 82.5 67.01 77.72 81.04 84.51 90.55 93.79 95.50 97.28 97.75 98.31 99.52 87.47 220.59 85.0 71.88 80.44 81.85 83.11 88.60 93.60 96.00 97.35 97.99 98.38 99.29 88.45 159.23 87.5 77.57 82.01 85.72 88.00 90.18 94.27 96.19 97.77 98.31 98.78 99.50 90.33 112.58 90.0 79.79 83.98 87.89 89.58 92.21 95.51 97.36 98.28 98.64 99.08 99.64 91.73 93.80 92.5 82.46 86.89 89.74 91.71 93.24 95.40 97.17 98.29 98.64 98.91 99.51 92.73 67.53 95.0 84.88 89.87 91.57 93.69 95.33 97.13 97.91 98.71 99.04 99.31 99.82 93.89 73.69 97.5 95.04 98.46 99.26 99.82 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.33 22.25 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 0 to 6 hours 2.5 0 0 0 0 0 0 0 0 0 0 0 0.24 1.34 

5.0 .67 1.10 1.16 1.66 1.94 2.45 3.45 4.47 5.52 6.44 9.95 3.68 9.62 7.5 .78 1.78 2.59 3.80 5.04 5.51 6.43 8.77 9.47 10.16 17.34 6.74 25.23 

10.0 1.55 2.88 4.49 5.35 6.23 7.41 9.28 13.22 15.24 17.57 20.70 10.47 92.61 12.5 1.56 2.20 2.76 4.92 6.33 8.51 10.23 13.06 14.32 17.66 23.39 9.88 53.53 15.0 5.65 6.64 6.99 7.63 9.52 10.57 10.98 15.95 16.50 17.00 34.40 13.09 70.01 17.5 4.28 7.46 7.61 10.05 12.75 13.59 17.28 20.44 21.22 23.17 25.95 14.79 58.42 20.0 6.31 13.01 14.58 15.98 17.54 20.85 23.58 25.87 26.40 26.75 36.44 21.00 105.43 22.5 3.49 7.05 7.63 8.06 15.90 18.64 23.39 26.93 29.68 30.24 53.98 22.27 310.04 25.0 4.47 8.16 8.37 18.65 24.64 29.93 33.87 37.68 41.90 43.95 52.71 27.96 264.29 27.5 7.41 10.51 15.28 18.90 22.05 26.85 30.44 39.11 41.73 48.09 54.03 29.14 289.21 30.0 6.88 16.76 22.95 27.85 30.40 34.31 41.89 47.59 52.57 56.49 65.39 36.40 365.12 32.5 18.54 31.84 34.34 35.51 42.05 47.15 50.59 59.63 62.72 65.39 72.98 46.82 368.93 35.0 7.63 15.39 28.37 36.74 38.37 46.43 54.14 54.72 64.95 66.87 73.85 43.87 489.23 37.5 22.55 34.07 37.88 39.40 43.63 48.78 56.49 62.71 67.37 68.79 78.48 50.00 399.56 40.0 7.80 42.18 43.91 48.88 51.74 56.96 63.42 67.05 67.90 71.76 82.54 53.99 525.94 42.5 25.85 41.33 48.56 49.56 54.92 58.04 69.20 72.18 73.77 78.10 86.33 58.76 425.45 45.0 16.27 41.31 45.52 54.05 68.63 75.76 77.62 79.93 80.26 80.66 85.42 63.22 618.36 47.5 21.04 45.72 53.94 56.55 60.78 65.78 71.92 79.39 82.47 83.90 91.06 63.29 558.70 50.0 56.08 59.59 61.31 62.95 70.67 74.26 82.94 85.34 86.06 86.38 89.79 73.67 199.03 52.5 46.95 59.47 62.70 65.90 69.93 77.42 82.80 84.96 86.77 88.33 92.77 72.47 389.88 55.0 41.40 55.54 56.81 60.20 67.17 73.24 80.79 87.95 88.34 90.49 92.59 70.26 455.34 57.5 42.06 62.64 66.45 67.21 72.96 79.03 85.35 88.47 89.53 90.58 92.62 74.09 411.48 60.0 37.36 69.56 74.23 75.12 79.32 84.61 86.51 88.08 89.34 90.55 94.57 77.05 437.25 62.5 57.36 68.09 69.99 73.04 74.86 82.86 88.74 89.71 90.44 92.30 95.67 78.65 285.05 65.0 60.06 67.10 69.36 70.35 74.66 77.82 85.38 88.85 89.95 92.74 96.37 78.30 201.89 67.5 71.45 76.86 78.32 79.79 87.67 90.11 92.14 93.65 93.85 94.91 96.61 85.93 130.97 70.0 70.95 77.76 82.15 85.08 90.52 91.92 93.56 94.33 94.75 95.85 97.99 88.39 89.04 72.5 77.21 82.75 86.17 86.80 90.61 92.38 93.48 94.03 94.66 95.75 96.92 89.61 56.44 75.0 81.51 84.94 88.41 88.66 91.60 94.33 95.16 96.87 97.56 97.69 98.52 91.72 49.03 77.5 79.01 84.28 84.88 87.26 92.14 94.57 96.00 97.46 97.74 98.66 99.08 91.79 53.37 80.0 87.74 90.43 90.70 91.64 93.32 95.49 95.82 96.81 97.16 98.52 99.80 93.51 44.58 82.5 87.93 90.50 91.84 92.62 93.30 95.66 96.65 97.02 97.74 98.66 99.77 94.29 22.46 85.0 96.52 96.82 97.29 97.78 97.98 98.20 98.44 98.82 98.84 98.93 99.51 98.14 1.00 87.5 92.73 94.61 95.00 95.19 96.91 98.01 98.35 98.58 98.66 98.87 99.35 96.45 14.66 90.0 92.01 95.00 96.15 96.45 97.12 98.30 98.78 98.96 99.07 99.17 100.00 97.21 6.95 92.5 96.03 97.14 97.18 97.94 98.46 98.62 99.10 99.41 99.56 99.79 100.00 98.16 5.25 95.0 95.17 96.81 97.84 98.01 99.09 99.27 99.32 99.42 99.51 99.58 100.00 98.48 2.73 97.5 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.98 .01 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 6 to 12 hours

2.5 0 0 0 0 0 0 0 0 0.66 1.51 5.73 1.78 25.25 5.0 .83 1.72 1.81 1.99 2.95 3.92 5.48 7.61 8.64 11.75 23.70 7.77 85.32 7.5 .96 1.85 2.52 4.06 5.69 6.52 8.74 12.08 14.39 18.01 35.01 11.94 184.23 

10.0 2.73 4.83 6.16 6.66 8.32 10.73 12.62 17.01 20.61 26.48 34.12 14.23 129.57 12.5 2.16 6.63 8.90 11.64 12.29 14.39 16.68 27.62 32.67 34.07 39.87 18.96 228.05 15.0 3.88 6.78 8.43 11.45 16.86 17.52 21.52 34.02 34.13 34.51 40.48 21.12 176.95 17.5 5.46 7.99 8.39 9.91 16.85 20.10 21.44 34.10 34.51 40.31 45.30 22.82 271.05 20.0 4.47 12.83 14.29 14.91 20.94 24.64 27.09 34.00 34.13 34.51 53.81 25.60 245.90 22.5 6.69 11.28 13.12 14.36 17.61 21.14 27.95 29.44 34.23 38.18 61.62 27.03 397.27 25.0 8.45 18.89 19.69 20.45 23.77 29.18 34.48 37.90 40.61 40.99 66.03 32.53 418.63 27.5 10.12 15.07 20.66 25.20 30.91 33.19 35.74 41.12 44.58 57.25 79.37 36.54 516.49 30.0 11.37 15.32 17.99 23.10 28.03 33.05 36.20 45.83 58.39 70.43 80.62 38.54 563.85 32.5 12.79 17.46 20.67 24.54 35.63 37.79 42.78 51.82 60.73 69.40 86.91 42.90 681.37 35.0 12.65 19.49 24.59 26.46 31.45 38.12 42.79 56.90 62.34 71.68 92.29 43.98 699.92 37.5 18.01 22.39 25.35 27.26 35.64 42.20 45.16 54.55 58.17 72.12 82.69 45.51 568.69 40.0 29.68 31.80 33.93 36.91 44.53 47.31 50.92 60.63 64.01 67.34 81.69 51.44 388.13 42.5 25.41 38.03 43.43 48.86 52.60 55.69 61.59 65.35 68.87 72.63 83.91 55.89 453.77 45.0 33.59 41.45 46.04 49.32 55.12 58.87 63.08 71.09 76.40 81.48 88.88 60.01 428.35 47.5 29.39 42.52 47.79 52.46 61.68 62.60 67.37 74.69 78.06 80.19 91.16 61.96 480.26 50.0 33.77 47.32 50.80 60.99 64.37 70.46 72.17 75.79 78.59 79.40 87.67 64.67 368.98 52.5 31.47 48.65 54.21 56.58 61.95 65.12 67.42 74.77 77.46 80.42 89.15 63.25 406.28 55.0 44.60 52.72 59.00 62.39 68.73 72.34 75.38 82.61 84.01 87.43 90.30 69.97 295.20 57.5 45.48 55.29 59.35 63.69 70.12 75.38 78.26 83.23 83.62 85.53 93.25 71.00 317.72 60.0 57.08 61.73 63.01 63.60 68.75 72.46 77.53 85.35 87.88 89.75 95.21 73.46 275.03 62.5 63.66 66.79 71.75 72.79 79.82 84.92 87.36 89.22 90.21 90.59 92.41 80.61 128.60 65.0 65.80 73.19 74.01 76.31 79.21 84.51 87.88 90.93 91.68 92.57 96.87 81.40 187.02 67.5 68.12 77.99 78.30 79.94 86.21 88.51 90.00 92.63 93.93 94.82 98.53 85.40 123.09 70.0 67.62 78.08 79.30 81.30 83.96 89.34 92.04 94.40 94.85 97.02 98.82 85.86 148.34 72.5 74.11 82.08 82.89 83.23 85.85 89.95 92.88 95.85 96.49 96.76 99.32 87.62 145.87 75.0 71.79 79.79 82.50 83.74 90.89 91.91 93.71 96.56 97.07 97.85 99.18 88.45 126.49 77.5 66.71 79.61 83.80 85.37 91.24 93.26 93.71 96.08 97.25 97.98 99.03 88.09 151.82 80.0 75.15 82.12 83.28 86.10 87.72 93.60 94.59 96.21 97.67 98.71 99.38 90.21 65.31 82.5 82.15 87.04 87.61 88.42 91.88 95.56 96.67 97.90 98.81 99.58 100.00 92.85 44.51 85.0 80.64 88.94 90.17 90.97 94.72 96.77 98.15 98.64 98.76 99.04 99.96 93.59 54.09 87.5 88.84 89.86 90.60 92.10 95.47 97.61 98.52 98.92 99.62 100.00 100.00 95.46 20.91 90.0 87.32 91.74 93.17 93.38 95.36 96.97 98.01 99.00 99.15 99.52 100.00 95.41 22.74 92.5 91.59 94.19 95.07 96.29 97.37 98.44 98.94 99.50 99.92 100.00 100.00 97.04 11.65 95.0 94.64 96.54 97.11 98.22 98.95 99.14 99.32 99.67 99.92 100.00 100.00 98.35 3.72 97.5 98.73 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.64 1.16 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 12 to 24 hours 2.5 0 0 0 0 0 0 0.66 1.37 2.01 2.72 5.85 2.14 20.99 

5.0 .50 2.08 2.40 2.58 3.07 4.97 6.52 9.06 9.72 11.07 17.23 7.60 67.53 7.5 2.61 4.24 4.86 5.58 8.39 10.48 13.04 17.15 19.37 23.87 34.49 14.54 162.11 

10.0 4.23 6.25 7.52 8.46 9.54 11.83 16.21 21.55 29.33 35.31 42.10 17.67 197.10 12.5 4.52 7.95 9.29 10.86 12.71 15.55 18.55 31.80 36.33 37.05 43.40 20.84 228.08 15.0 8.84 11.01 11.81 13.51 18.58 20.68 30.59 37.05 38.13 38.77 46.07 25.63 254.48 17.5 7.22 12.15 13.85 15.08 20.23 24.09 32.04 38.00 38.38 40.18 43.55 26.81 248.18 20.0 2.00 8.90 11.13 13.83 18.03 23.02 28.47 38.00 41.11 43.65 57.70 26.90 381.18 22.5 4.64 12.16 15.18 18.36 21.98 25.70 35.19 41.60 46.30 52.90 64.03 30.97 426.91 25.0 9.64 16.54 20.22 23.16 27.47 34.54 39.47 42.38 43.92 63.10 67.26 36.03 428.13 27.5 4.25 12.84 15.22 20.77 26.44 32.79 42.05 47.55 49.70 52.80 70.09 35.08 541.71 30.0 5.78 17.19 22.58 25.26 33.65 38.00 41.78 49.59 51.32 53.31 70.42 37.23 439.07 32.5 10.24 22.96 27.31 30.09 32.92 41.31 44.14 51.14 53.61 55.01 63.57 39.27 351.01 35.0 13.34 25.53 29.03 33.16 40.00 47.10 54.39 59.90 63.28 65.19 72.78 46.00 452.18 37.5 13.85 23.58 26.95 32.07 43.75 50.70 53.61 62.55 72.65 75.90 81.82 48.27 617.59 40.0 14.67 22.99 25.72 31.85 39.30 49.41 55.89 65.63 71.13 75.29 87.19 49.27 673.28 42.5 23.83 31.28 35.67 37.93 46.00 52.73 61.05 72.59 75.18 78.56 85.79 54.67 542.13 45.0 32.41 38.18 43.55 46.73 53.61 63.41 71.89 77.04 78.22 80.13 92.27 61.29 490.75 47.5 37.73 44.91 49.45 53.97 60.06 64.67 70.11 78.25 79.42 83.60 92.88 64.51 425.73 50.0 41.32 51.55 52.86 57.95 66.14 70.55 73.42 79.39 82.04 84.11 93.80 67.94 357.23 52.5 44.91 56.32 59.57 63.72 71.32 75.58 79.39 83.99 84.64 86.96 96.66 71.69 389.16 55.0 46.86 57.77 60.42 64.56 71.39 75.90 80.59 85.43 86.74 89.62 93.76 72.43 363.35 57.5 49.61 59.27 60.99 63.19 71.81 76.46 80.64 87.20 89.42 91.09 95.30 73.40 380.39 60.0 63.35 68.77 71.62 75.16 80.44 82.83 88.35 91.73 93.30 94.04 98.06 81.17 236.27 62.5 51.48 62.05 69.81 71.54 76.59 82.58 86.53 91.01 94.70 95.10 98.22 77.69 394.70 65.0 59.23 73.66 78.37 80.17 81.97 86.27 88.94 93.45 95.84 97.79 99.10 82.20 297.22 67.5 58.14 70.57 74.59 76.50 81.16 85.31 88.39 91.30 92.30 93.49 98.06 80.96 251.18 70.0 60.98 70.11 76.84 78.98 83.55 87.34 91.98 94.20 95.53 96.54 99.32 83.00 258.45 72.5 59.44 69.14 71.94 72.96 80.92 83.33 88.36 91.98 94.86 95.72 97.44 80.59 281.89 75.0 66.36 77.03 80.39 82.94 84.61 88.68 90.91 94.75 97.15 98.00 99.29 85.14 222.88 77.5 67.71 81.44 83.55 84.34 86.58 87.82 91.00 94.47 95.98 97.72 98.67 86.36 178.25 80.0 71.00 82.95 84.64 85.94 89.80 91.64 93.29 95.28 96.73 98.44 99.34 88.80 104.03 82.5 74.40 80.21 84.98 85.57 91.07 93.36 94.90 96.48 97.08 98.63 99.68 89.41 121.20 85.0 81.16 85.36 86.90 88.64 92.83 94.81 95.87 97.36 97.94 98.56 98.86 91.53 74.84 87.5 87.09 89.22 90.63 92.19 94.50 96.84 97.41 98.72 98.93 99.23 100.00 94.32 35.13 90.0 84.85 90.50 92.96 95.05 96.84 97.71 98.46 98.80 99.33 99.58 100.00 94.94 39.45 92.5 86.66 93.24 94.90 95.83 97.91 98.50 98.76 99.10 99.11 99.37 99.66 95.71 34.72 95.0 80.42 91.98 94.77 97.21 98.58 98.94 99.28 99.40 99.65 99.70 100.00 95.44 60.99 97.5 96.57 99.49 99.70 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.56 23.29 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 24 to 72 hours

2.5 0 0 0 0 0.60 2.03 3.51 5.65 7.39 10.47 22.42 6.28 93.98 5.0 1.60 2.89 5.02 6.21 9.67 13.92 19.64 23.86 31.57 40.70 50.39 21.00 429.77 7.5 2.59 4.78 6.98 9.46 16.42 20.44 36.75 44.82 48.65 50.22 63.75 28.90 521.48 

10.0 1.07 5.28 7.63 9.96 15.91 40.70 54.87 57.45 60.07 63.14 67.92 35.32 752.49 12.5 2.37 4.78 7.68 8.26 13.90 36.60 66.09 69.57 71.53 74.44 81.17 40.36 1076.84 15.0 2.63 5.05 6.30 8.26 9.94 16.48 48.80 70.87 73.04 77.82 82.06 36.27 1,091.03 17.5 1.44 4.42 5.22 6.63 10.65 14.96 27.37 60.71 75.67 79.30 84.07 34.08 1,102.69 20.0 3.72 7.76 8.72 10.51 15.98 22.84 28.10 60.71 67.93 80.00 86.26 35.84 973.65 22.5 3.22 6.22 7.10 8.54 12.11 18.89 24.67 29.09 41.71 63.50 82.72 28.69 798.07 25.0 4.63 8.32 8.84 10.85 23.77 27.91 30.47 51.67 58.06 64.46 82.72 34.49 763.18 27.5 3.04 8.54 9.77 10.85 18.70 30.89 37.62 57.29 62.45 69.88 81.31 35.97 821.87 30.0 6.16 10.89 14.16 18.38 31.15 34.44 46.56 54.67 61.49 62.83 84.42 39.66 718.87 32.5 6.93 11.28 12.52 14.58 19.64 32.79 38.58 42.26 46.64 55.06 62.89 32.67 481.20 35.0 8.78 12.22 13.68 16.95 26.95 36.93 43.32 49.04 56.72 63.02 78.65 38.10 634.07 37.5 11.04 14.93 16.82 18.28 29.02 43.39 50.02 55.42 62.02 64.14 71.29 40.46 579.52 40.0 12.77 18.79 19.99 22.95 32.78 42.64 54.60 63.08 64.78 70.93 78.31 44.46 598.32 42.5 19.70 26.35 27.89 29.63 34.62 40.85 46.34 59.52 66.92 71.38 83.31 46.45 547.74 45.0 24.81 35.43 39.01 42.18 45.30 50.12 56.30 60.74 69.57 72.09 84.09 52.87 439.70 47.5 35.19 45.01 47.93 52.27 55.17 58.50 62.03 70.41 73.84 75.39 84.95 59.45 383.04 50.0 41.63 49.29 54.12 56.65 59.73 63.42 68.69 75.42 76.99 78.48 84.79 63.54 325.84 52.5 44.02 56.87 58.78 59.85 61.88 63.13 66.67 75.27 77.35 77.98 86.86 65.45 262.92 55.0 49.30 57.16 59.35 61.24 63.41 67.44 76.72 80.44 82.04 84.95 89.02 68.71 304.48 57.5 59.04 61.24 63.41 64.62 70.78 75.27 79.81 83.72 84.95 86.14 91.33 73.84 241.70 60.0 61.31 66.62 71.59 75.30 80.83 84.29 86.67 88.44 90.72 91.27 96.76 80.46 183.98 62.5 62.75 69.69 73.66 75.62 85.00 87.79 91.01 94.41 94.98 95.63 97.57 83.54 184.95 65.0 65.41 72.85 75.62 78.88 84.86 88.37 91.67 96.40 97.34 97.64 98.30 84.05 272.09 67.5 64.53 77.19 79.79 82.73 87.55 90.27 96.03 97.70 98.24 98.30 98.51 86.71 192.94 70.0 63.89 78.37 83.66 85.90 90.47 93.84 96.09 97.97 98.43 98.54 98.64 87.52 210.48 72.5 53.46 74.01 77.87 79.42 86.61 92.18 94.34 96.91 97.25 98.23 98.54 83.67 346.47 75.0 58.81 70.37 75.87 86.09 90.95 93.18 95.36 96.47 96.94 97.54 98.56 85.38 289.26 77.5 51.93 66.10 76.70 79.84 86.67 92.61 94.72 97.25 97.81 98.27 98.89 83.44 382.39 80.0 64.19 66.21 72.39 76.68 80.69 88.24 93.12 97.21 97.81 98.39 99.06 83.61 247.07 82.5 67.24 73.90 76.24 77.68 84.15 89.54 94.11 96.27 97.25 97.64 98.98 85.96 151.76 85.0 72.20 76.14 77.33 80.09 84.43 91.28 94.04 97.35 98.25 98.32 99.01 87.40 118.38 87.5 71.89 76.14 78.07 83.85 88.01 94.17 96.04 97.98 98.41 99.01 99.47 87.76 228.48 90.0 63.90 74.89 77.94 79.86 84.52 87.40 90.88 94.32 96.48 98.38 98.98 82.64 386.37 92.5 74.80 82.28 85.29 87.76 90.07 93.98 97.00 98.46 98.78 98.98 99.56 89.57 146.91 95.0 80.28 88.24 90.75 92.26 94.19 95.26 97.59 99.20 99.32 99.37 99.66 93.31 61.57 97.5 89.72 93.94 95.13 96.25 97.67 98.49 99.62 100.00 100.00 100.00 100.00 96.76 18.92 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Second-quartile storms; storm duration 0 to 72 hours 2.5 0 0 0 0 0 0 0.62 2.03 3.08 4.37 10.54 3.36 52.26 

5.0 1.10 1.99 2.44 2.70 4.41 6.62 9.36 13.57 17.23 21.44 39.16 13.13 269.89 7.5 1.79 4.05 4.60 5.51 8.39 11.11 16.03 23.27 32.93 37.19 50.09 19.32 370.01 

10.0 2.33 5.32 6.50 7.39 9.36 12.31 17.81 29.19 37.02 43.40 59.28 22.61 482.18 12.5 2.31 6.11 7.92 9.17 12.01 15.42 20.45 36.33 39.04 58.05 71.79 27.16 667.67 15.0 4.73 7.59 8.78 10.54 13.90 17.61 23.54 37.05 40.00 45.18 73.62 27.82 606.85 17.5 3.57 7.61 9.60 11.66 14.67 19.60 24.24 34.46 38.67 42.86 69.56 26.99 550.08 20.0 4.43 9.75 12.08 13.87 17.76 22.86 25.62 34.13 38.00 43.96 62.52 28.39 516.76 22.5 4.26 7.24 9.96 12.35 17.86 21.93 26.39 34.15 38.84 46.75 65.34 28.08 529.71 25.0 5.25 10.82 16.38 20.14 25.18 29.39 35.15 41.89 44.59 56.71 68.84 33.90 532.34 27.5 4.86 10.64 12.96 16.08 25.17 31.29 37.39 45.87 50.50 60.96 72.47 34.68 603.59 30.0 7.29 14.38 18.73 23.53 31.08 34.75 41.49 51.23 53.55 57.66 73.68 38.29 560.58 32.5 10.06 15.46 20.24 25.00 33.11 38.00 42.62 50.54 54.19 58.87 71.18 38.98 499.31 35.0 11.41 15.79 19.62 25.86 33.73 40.91 46.78 56.32 59.36 64.66 76.34 42.10 594.00 37.5 13.07 19.56 23.57 27.77 38.62 45.32 52.19 59.35 63.29 69.06 78.49 45.03 581.28 40.0 15.17 22.95 27.18 31.87 40.81 48.56 56.06 63.92 67.01 71.57 82.20 48.19 592.32 42.5 22.60 28.48 31.27 35.58 43.73 51.81 58.20 67.92 71.64 75.06 83.97 52.00 540.47 45.0 29.57 38.38 42.37 44.35 50.46 58.03 64.68 75.27 76.80 78.77 87.63 58.17 499.44 47.5 35.32 44.42 49.15 52.88 58.14 61.89 66.50 74.91 77.80 80.57 88.70 61.88 435.53 50.0 42.10 51.72 55.58 57.89 63.61 68.54 73.26 77.30 79.39 82.98 88.74 66.68 337.30 52.5 43.49 56.35 58.43 60.84 63.26 67.47 74.89 78.77 81.38 84.45 90.08 67.84 355.62 55.0 47.06 56.93 59.35 61.75 66.97 72.00 78.47 82.95 85.04 87.23 91.94 70.36 348.71 57.5 54.89 60.25 62.50 65.17 70.96 75.54 79.89 84.59 86.56 88.47 93.57 73.30 317.29 60.0 61.16 66.62 69.72 72.83 77.94 83.00 86.58 89.09 90.38 91.84 96.81 78.94 262.20 62.5 60.52 68.49 71.31 73.46 79.22 86.15 88.37 91.30 94.05 94.97 97.25 80.64 263.07 65.0 63.59 72.29 75.00 77.66 81.28 86.56 88.86 93.49 95.81 97.03 98.31 82.48 260.73 67.5 63.46 75.82 77.95 79.87 85.04 88.51 91.13 93.64 94.94 96.17 98.50 84.52 190.72 70.0 63.82 77.36 79.24 81.90 87.42 90.75 93.68 95.34 96.94 97.78 98.65 85.93 199.71 72.5 64.95 74.77 78.42 80.87 84.95 89.48 92.39 94.92 96.09 96.50 98.54 84.37 251.59 75.0 66.27 78.86 82.18 83.92 88.68 91.75 94.12 96.13 97.06 97.66 98.66 86.63 213.53 77.5 63.93 79.41 83.29 84.42 87.38 92.11 94.13 96.67 97.41 97.96 98.84 86.57 229.12 80.0 66.67 79.25 82.58 85.42 89.52 91.89 94.09 96.66 97.23 98.40 99.08 87.95 151.83 82.5 74.56 80.38 85.03 87.34 90.55 93.51 95.43 96.84 97.47 98.30 99.28 89.62 112.07 85.0 75.58 82.62 85.91 88.64 92.24 95.07 97.03 98.12 98.36 98.60 99.25 90.97 92.53 87.5 77.78 87.51 89.27 90.71 94.25 95.88 97.53 98.53 98.82 99.21 99.71 92.12 122.61 90.0 77.85 85.17 87.71 90.75 93.65 96.40 97.84 98.60 98.84 99.07 99.66 91.07 194.12 92.5 83.19 89.27 91.07 93.54 96.66 98.02 98.59 99.00 99.11 99.32 100.00 93.82 83.63 95.0 86.16 92.35 93.90 94.79 97.26 98.60 99.20 99.34 99.43 99.64 100.00 95.29 50.42 97.5 94.04 97.56 98.29 99.27 100.00 100.00 100.00 100.00 100.00 100.00 100.00 98.23 15.66 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 0 to 6 hours

2.5 0 0 0 0 0 0 0 0 0 0 3.33 0.55 2.41 5.0 .94 1.71 1.83 1.95 3.73 4.67 6.36 14.17 16.87 19.57 25.42 8.72 69.88 7.5 1.21 2.00 2.38 2.66 4.66 6.31 9.29 10.83 11.31 14.02 28.51 9.03 70.67 

10.0 1.25 1.85 2.88 4.72 5.34 11.63 15.00 15.00 16.30 16.73 32.85 11.81 96.57 12.5 1.16 1.96 3.01 4.23 13.86 15.61 16.67 18.03 21.42 23.63 34.35 14.82 115.49 15.0 -- 4.58 5.67 6.02 12.30 18.72 25.91 33.10 33.10 33.67 -- 19.04 171.03 17.5 2.78 9.38 10.44 11.74 16.67 16.67 18.18 22.73 25.68 27.50 35.19 17.85 98.12 20.0 2.34 8.38 10.91 13.65 20.08 21.67 26.87 31.58 31.92 32.65 33.83 20.98 123.07 22.5 2.31 2.63 3.77 8.83 14.96 18.25 18.60 22.50 22.50 26.25 36.87 16.87 129.44 25.0 4.55 6.12 7.05 8.87 10.92 14.37 19.55 28.21 30.27 32.19 39.12 18.39 147.89 27.5 1.62 10.38 13.42 21.31 24.17 24.17 28.97 33.10 33.10 36.45 40.02 24.27 152.65 30.0 3.86 11.91 15.04 17.08 18.96 25.83 25.83 31.64 35.97 40.15 52.86 25.31 223.08 32.5 4.73 12.32 13.39 15.12 18.01 21.88 28.33 32.87 33.10 37.43 45.63 24.15 190.56 35.0 -- 3.52 4.44 5.98 7.91 12.05 18.44 25.84 30.50 34.55 -- 16.77 172.47 37.5 21.34 28.33 28.33 28.33 28.91 34.05 37.29 39.59 42.15 44.66 55.60 35.50 125.86 40.0 3.99 8.97 22.22 26.26 28.36 30.00 31.69 33.87 36.99 44.42 71.38 31.62 398.00 42.5 2.06 12.86 20.82 23.71 24.70 32.68 34.17 35.61 40.15 44.62 52.55 30.36 311.33 45.0 0 19.92 19.92 19.92 21.26 33.81 34.43 39.73 61.79 83.84 85.03 37.55 747.04 47.5 7.45 13.05 16.07 20.90 35.48 36.67 36.67 44.16 53.32 61.53 66.33 35.99 427.10 50.0 10.63 27.94 28.67 30.77 33.94 40.87 43.54 44.17 47.65 53.10 71.82 40.77 436.92 52.5 21.38 21.88 28.57 28.69 36.54 44.07 47.46 56.67 56.67 56.67 80.91 44.24 428.15 55.0 36.11 37.58 37.89 42.16 48.34 56.81 57.39 60.79 62.99 81.52 94.54 57.26 384.36 57.5 33.18 40.49 40.95 41.25 42.70 49.35 58.04 68.21 78.54 81.67 82.88 56.11 383.25 60.0 20.66 40.41 41.04 45.59 53.89 56.57 65.01 83.90 85.00 85.00 88.73 59.23 607.50 62.5 2.72 43.27 49.53 56.12 58.18 62.28 71.19 75.00 85.83 85.83 87.38 58.92 732.17 65.0 4.29 9.43 27.87 43.20 59.09 62.19 67.62 70.23 71.73 74.24 80.63 52.25 716.22 67.5 25.32 52.80 54.69 58.73 68.18 69.12 74.36 79.33 82.80 85.83 90.26 66.10 471.33 70.0 19.08 54.76 65.83 68.28 72.25 75.66 80.48 84.65 85.83 85.83 92.41 68.69 610.25 72.5 41.02 55.88 58.89 63.82 70.89 72.13 84.54 85.83 86.06 87.01 93.78 72.34 291.21 75.0 48.11 63.88 70.50 73.19 75.06 78.53 81.75 85.21 85.81 86.35 90.82 75.55 202.54 77.5 62.97 79.64 81.75 82.21 83.68 85.83 89.62 90.72 90.99 91.29 92.83 83.86 111.58 80.0 66.69 77.28 79.86 81.13 85.35 85.83 87.68 89.99 91.42 92.15 94.93 84.38 84.21 82.5 73.78 84.70 85.49 85.67 85.83 86.86 88.17 89.35 91.49 92.15 97.08 85.54 117.07 85.0 76.45 82.78 83.56 85.40 90.14 92.86 93.67 94.99 96.48 98.06 98.66 90.22 52.43 87.5 85.39 85.83 87.52 89.77 92.32 95.04 95.10 96.59 96.99 97.36 98.67 92.80 23.90 90.0 85.41 90.57 91.55 92.50 92.50 94.89 96.72 97.09 97.11 97.21 99.10 93.93 17.33 92.5 91.58 93.58 95.45 95.71 96.78 98.00 98.24 98.33 98.63 98.78 99.14 96.27 14.11 95.0 94.97 97.75 97.81 97.87 98.02 98.24 98.56 98.97 99.22 99.49 99.96 98.20 1.92 97.5 99.17 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.80 .38 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 6 to 12 hours 2.5 0 0 0 0 0 0 0 1.56 1.97 2.67 5.70 1.88 17.22 

5.0 1.25 2.33 2.37 2.51 3.14 4.42 5.72 8.96 9.16 9.54 14.05 6.44 38.54 7.5 .66 2.61 3.42 3.91 4.54 8.19 8.96 11.13 12.29 12.39 15.20 7.61 25.64 

10.0 2.13 3.80 4.94 5.83 7.31 8.65 11.20 16.73 18.95 20.67 21.98 12.28 102.53 12.5 1.63 5.04 6.17 7.78 9.56 10.47 11.38 14.42 16.34 17.76 21.09 11.34 48.33 15.0 1.72 3.94 5.06 6.08 11.50 14.67 16.83 20.92 26.11 28.97 33.77 16.19 146.50 17.5 1.02 6.17 6.27 6.86 9.86 12.56 13.49 19.04 21.30 25.74 33.03 14.70 132.61 20.0 5.39 11.43 12.73 14.17 14.29 16.34 19.76 24.52 31.49 32.62 44.17 20.73 161.32 22.5 2.19 6.06 10.16 14.03 14.29 14.75 16.33 22.73 27.25 31.66 38.60 18.25 165.89 25.0 3.25 6.88 10.57 11.21 14.26 20.26 30.27 32.29 37.30 42.50 44.84 23.02 239.26 27.5 8.47 12.50 14.20 14.29 16.97 21.20 30.52 35.59 40.52 44.84 53.04 26.26 248.45 30.0 3.29 6.99 10.97 11.70 14.24 21.61 31.87 32.29 36.79 44.46 45.82 24.55 279.04 32.5 1.29 7.00 11.41 13.06 16.15 19.18 32.36 36.85 41.77 44.84 49.79 24.80 322.35 35.0 5.91 10.04 11.97 13.05 16.99 21.85 33.64 39.34 44.36 44.84 54.58 27.62 336.41 37.5 5.07 8.62 12.87 13.71 16.23 21.05 22.90 32.74 33.72 38.00 51.61 23.64 232.48 40.0 6.28 10.93 13.45 14.24 18.81 21.09 30.34 34.58 37.17 44.84 49.63 25.60 233.65 42.5 6.91 14.17 14.29 15.48 21.86 28.00 29.50 36.01 39.85 40.84 51.37 27.81 270.47 45.0 3.82 6.49 8.30 11.41 15.33 19.06 25.73 32.90 41.18 41.79 46.65 23.18 269.18 47.5 3.53 9.88 11.90 15.48 20.86 22.88 24.77 31.81 33.13 41.90 53.82 25.08 264.34 50.0 10.97 14.17 14.31 16.46 25.14 27.85 32.35 34.56 36.84 40.88 53.45 29.78 302.43 52.5 6.08 15.05 21.41 24.99 27.27 32.46 37.30 42.18 49.29 55.01 57.62 33.97 387.98 55.0 10.84 23.24 27.18 29.18 31.91 35.09 41.57 49.10 51.18 55.61 71.60 39.30 448.36 57.5 6.62 16.51 20.63 27.39 31.25 37.21 41.01 51.41 55.81 60.06 74.85 39.55 571.47 60.0 13.62 17.12 23.70 27.92 33.19 41.15 45.80 54.03 55.94 60.77 74.71 41.52 510.82 62.5 20.22 31.69 33.09 35.63 42.11 48.02 51.61 59.90 64.01 69.08 80.26 49.23 487.04 65.0 18.68 32.05 36.12 39.55 47.26 58.82 62.82 66.33 73.80 76.25 82.35 53.93 540.59 67.5 20.93 32.23 35.08 43.48 47.59 57.90 63.22 68.99 72.35 78.01 84.66 55.06 515.30 70.0 24.19 41.61 45.07 48.18 59.42 61.87 65.92 74.95 79.85 81.96 87.43 59.92 496.27 72.5 19.84 43.62 49.49 55.66 61.99 67.68 76.15 82.41 83.69 86.57 91.90 63.93 601.86 75.0 22.95 47.66 50.79 60.15 69.79 75.35 81.25 85.47 86.38 88.05 91.69 67.86 579.27 77.5 49.65 60.74 64.59 69.35 75.73 81.37 85.68 90.28 91.50 92.48 95.97 76.38 351.52 80.0 61.33 71.22 73.01 76.67 82.10 85.83 87.35 90.27 91.82 93.18 96.62 81.21 222.00 82.5 61.66 78.60 80.33 82.29 87.47 89.45 90.60 93.49 94.39 95.34 97.13 85.09 175.94 85.0 66.34 81.69 85.65 86.96 91.08 92.50 93.31 94.60 95.37 95.97 98.12 87.74 159.51 87.5 78.97 86.47 88.74 90.37 93.25 94.37 95.08 95.77 96.17 97.21 98.40 91.72 52.88 90.0 86.89 91.62 92.32 93.63 95.32 96.61 96.95 97.64 97.86 97.98 98.89 94.40 34.42 92.5 91.16 93.77 94.49 95.19 96.40 97.59 97.89 98.23 98.42 98.67 99.57 95.92 18.82 95.0 92.61 95.90 96.32 96.68 97.94 98.12 98.50 98.75 99.01 99.16 99.28 97.20 7.14 97.5 98.46 99.24 99.42 99.64 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.56 .85 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 12 to 24 hours

2.5 0 0 0 0 0 0 0.14 0.83 1.83 2.39 5.33 1.65 13.92 5.0 .67 1.13 1.25 1.85 2.82 5.00 5.98 7.99 8.95 13.07 19.13 7.16 58.93 7.5 1.17 1.85 2.46 3.87 4.46 5.29 5.78 7.42 8.86 9.54 18.78 7.21 47.64 

10.0 2.21 4.02 4.68 5.18 6.01 7.18 8.17 9.57 13.01 18.54 23.77 9.97 68.15 12.5 2.81 5.76 6.64 7.18 8.49 10.10 19.04 20.71 22.86 25.93 32.81 14.89 116.21 15.0 2.14 3.94 6.26 7.19 8.68 10.71 11.74 16.95 19.58 19.61 29.89 13.20 106.54 17.5 1.04 6.20 6.51 7.46 9.74 11.08 14.03 18.71 19.73 20.10 34.23 14.15 118.84 20.0 .88 6.29 6.98 8.70 8.82 10.25 14.93 19.88 20.85 21.31 31.14 14.18 112.05 22.5 1.88 6.75 7.59 8.67 13.12 15.26 16.45 20.10 21.11 22.67 30.84 15.64 96.37 25.0 .77 2.59 6.14 7.22 14.51 18.26 19.88 20.87 21.93 24.25 31.42 16.02 121.95 27.5 .71 5.34 7.33 11.09 14.28 18.18 20.69 26.12 27.99 31.19 34.80 18.39 148.07 30.0 2.36 5.34 6.30 7.49 14.80 20.00 21.43 28.33 28.59 31.48 37.81 19.34 180.01 32.5 1.03 6.53 8.22 8.48 10.95 15.08 20.00 22.52 22.99 28.00 35.79 16.94 140.09 35.0 1.80 4.82 5.26 6.75 10.03 12.50 17.11 23.43 23.63 24.95 36.24 15.87 150.45 37.5 3.49 7.02 7.86 8.83 12.95 20.00 23.24 26.18 27.63 31.80 35.17 19.29 169.90 40.0 2.37 3.80 4.47 5.83 9.37 16.75 19.19 28.53 30.27 30.68 38.86 18.44 206.11 42.5 1.29 6.44 8.69 9.67 11.59 14.29 20.00 26.70 31.13 32.42 45.14 19.53 251.12 45.0 3.28 6.04 7.61 9.73 13.88 18.38 20.90 29.14 30.00 30.92 39.85 20.64 263.92 47.5 3.90 7.19 8.14 10.19 12.41 18.04 19.96 23.25 26.59 28.89 43.41 19.87 214.79 50.0 4.63 9.35 10.18 11.99 18.18 19.88 22.86 31.58 34.95 36.49 39.78 22.34 173.73 52.5 9.22 12.44 14.52 19.69 23.25 26.82 31.09 38.61 40.93 41.80 48.42 27.64 202.13 55.0 10.92 15.77 17.07 19.66 22.33 32.76 39.95 44.12 47.02 49.98 57.73 33.66 335.80 57.5 13.74 21.29 23.16 28.55 32.73 39.36 45.62 51.08 54.22 59.68 73.18 40.81 439.75 60.0 14.36 22.77 25.75 30.85 38.79 45.84 52.40 59.38 64.60 68.59 84.11 46.18 543.15 62.5 26.73 36.96 40.10 42.67 50.30 54.67 60.14 63.80 67.57 76.68 88.52 55.25 451.85 65.0 29.04 38.54 41.27 46.15 56.91 61.52 66.97 72.97 77.13 80.02 89.98 59.49 507.73 67.5 25.38 43.50 49.37 51.02 58.91 66.55 72.45 76.95 81.41 83.22 93.57 62.88 518.30 70.0 36.95 44.04 45.07 51.77 62.67 70.01 73.81 79.88 83.20 85.09 89.79 65.42 430.34 72.5 33.49 46.27 52.18 55.78 62.54 72.31 80.00 83.04 85.87 87.06 94.28 67.60 515.46 75.0 44.76 56.25 60.23 64.10 68.79 76.79 83.47 86.33 87.76 88.91 96.82 72.95 371.37 77.5 44.84 62.76 67.27 69.75 74.21 78.10 84.76 87.19 89.01 90.17 96.41 75.85 309.76 80.0 57.56 64.86 70.29 74.02 79.24 84.73 86.69 87.54 88.46 89.76 96.63 79.51 197.00 82.5 67.45 74.99 79.83 80.26 85.60 87.95 89.12 90.69 91.35 93.18 97.94 84.61 130.56 85.0 69.96 76.24 78.21 80.26 86.26 89.16 91.34 92.85 94.10 96.73 98.74 85.77 128.84 87.5 74.75 81.51 84.78 88.79 90.28 91.30 92.47 94.43 95.96 96.98 99.16 89.17 82.56 90.0 81.30 83.98 86.13 87.64 91.25 92.51 95.60 97.27 97.64 98.05 99.07 91.59 48.96 92.5 84.58 87.92 89.72 90.97 92.39 94.17 96.42 97.42 98.08 98.68 99.10 93.21 31.20 95.0 85.35 92.38 93.59 94.38 95.29 96.51 97.24 98.45 98.71 99.21 100.00 94.81 29.36 97.5 92.52 97.79 98.46 99.10 99.70 100.00 100.00 100.00 100.00 100.00 100.00 98.23 13.36 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 24 to 72 hours 2.5 0 0 0 0 0.31 1.35 2.59 4.04 4.73 5.89 8.92 3.30 23.86 

5.0 1.26 3.22 3.47 3.85 5.61 6.06 7.85 10.28 11.30 13.02 24.87 9.30 81.61 7.5 2.84 4.91 6.06 6.48 8.52 11.03 11.75 13.44 13.79 15.66 21.02 11.45 71.38 

10.0 3.44 6.24 7.29 8.64 10.81 11.85 13.91 16.40 16.86 18.05 21.05 12.99 73.63 12.5 2.60 6.06 6.59 8.04 11.32 11.99 16.34 19.13 20.54 23.23 25.90 14.89 116.07 15.0 5.26 8.58 9.01 10.54 11.99 12.83 16.81 22.00 24.57 25.68 31.37 17.33 145.03 17.5 9.36 11.99 12.27 13.19 14.87 16.96 21.84 25.90 27.41 29.28 34.23 20.16 112.65 20.0 4.68 10.86 12.04 13.04 15.67 18.37 23.74 29.00 32.13 32.25 38.04 21.58 185.48 22.5 .85 5.59 7.74 11.96 15.29 16.44 21.28 25.00 28.08 32.13 37.54 19.30 204.72 25.0 3.06 8.99 10.69 11.50 13.91 18.72 24.70 26.80 30.73 32.13 35.78 20.56 189.84 27.5 9.58 11.81 13.25 13.47 17.97 20.85 25.45 30.07 30.70 31.08 36.24 23.11 192.38 30.0 7.11 13.14 15.39 19.64 22.80 26.77 29.30 31.97 32.13 33.51 40.67 26.16 216.61 32.5 7.04 11.09 13.24 14.92 21.18 25.38 28.38 33.28 34.63 36.19 42.60 26.12 270.18 35.0 4.32 9.61 11.13 12.01 21.48 26.81 28.73 32.18 35.23 36.34 41.29 24.53 232.95 37.5 7.89 12.18 13.20 14.66 20.76 29.51 33.16 38.06 38.92 39.85 67.43 29.75 378.65 40.0 6.87 13.47 15.69 17.38 22.60 28.34 35.37 39.03 40.46 41.09 48.90 28.95 306.94 42.5 9.64 13.44 17.98 18.98 25.21 29.72 32.18 38.28 41.29 42.37 49.29 29.66 273.11 45.0 4.24 10.18 10.55 11.86 18.81 25.60 31.52 36.67 38.14 42.73 51.99 27.32 389.38 47.5 7.41 10.46 10.87 12.73 14.53 18.85 28.05 35.57 37.00 39.18 45.58 25.00 315.58 50.0 8.62 14.84 16.41 18.23 20.00 23.27 28.50 34.20 38.00 41.60 51.13 27.41 262.03 52.5 10.30 21.65 24.65 27.18 30.95 36.51 38.60 41.57 42.66 43.89 50.67 34.07 233.54 55.0 17.57 32.52 35.48 39.19 42.48 46.77 49.61 54.18 56.07 58.33 74.79 45.87 353.44 57.5 15.46 38.20 42.63 44.02 48.20 53.58 59.27 67.44 72.32 76.18 83.46 53.59 508.51 60.0 19.48 36.64 41.06 42.33 44.61 50.62 58.21 67.02 73.39 76.89 84.73 53.12 561.35 62.5 18.08 26.51 36.61 42.11 49.73 55.50 62.28 67.30 71.98 76.14 85.22 53.35 588.06 65.0 19.35 23.21 27.25 37.73 47.39 51.92 62.17 67.26 68.94 76.13 82.71 51.48 572.93 67.5 23.20 35.33 42.59 46.81 54.75 66.76 69.42 74.76 78.61 82.04 87.23 59.52 572.43 70.0 23.85 42.54 49.24 54.17 61.76 66.24 72.02 80.97 86.19 89.19 96.07 64.48 603.88 72.5 26.67 50.42 55.32 62.62 68.54 74.38 81.24 88.40 89.19 89.19 97.47 69.77 583.88 75.0 29.96 46.10 54.51 57.10 68.28 74.15 80.92 84.96 87.81 89.55 97.78 68.74 589.66 77.5 26.29 53.53 59.00 62.60 70.48 79.22 83.93 88.51 90.03 93.69 97.13 70.70 640.07 80.0 26.27 39.96 49.43 55.27 66.92 74.92 81.77 89.25 91.77 95.95 97.47 68.51 713.66 82.5 38.11 52.15 58.21 65.32 76.55 81.19 84.24 88.99 91.26 96.14 97.65 73.13 563.53 85.0 37.74 60.09 67.52 70.61 81.14 85.40 89.14 91.77 94.34 96.12 97.47 77.02 491.26 87.5 47.75 71.58 75.09 77.60 84.04 87.36 91.62 95.24 96.15 97.25 98.09 81.76 349.29 90.0 49.27 66.83 75.47 81.51 86.51 88.28 93.49 97.23 97.48 97.88 99.24 82.82 338.94 92.5 75.02 84.30 86.59 88.18 90.16 92.11 94.05 96.02 97.37 98.03 99.55 90.08 82.21 95.0 89.41 91.87 93.34 94.07 95.16 95.93 96.80 98.03 98.42 98.62 99.57 95.18 17.07 97.5 96.31 97.70 98.16 98.56 99.15 99.55 100.00 100.00 100.00 100.00 100.00 98.65 4.77 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Third-quartile storms; storm duration 0 to 72 hours

2.5 0 0 0 0 0 0 0.92 2.36 3.22 4.20 7.23 2.37 19.06 5.0 1.12 2.33 2.77 3.35 4.61 5.93 6.98 9.14 10.65 12.65 20.83 8.40 70.91 7.5 1.73 3.47 4.10 4.74 6.24 8.29 10.83 11.91 12.94 13.68 18.43 9.68 62.12 

10.0 2.23 4.94 5.77 6.52 8.25 10.35 12.16 15.91 16.75 18.49 21.63 12.11 80.94 12.5 2.48 5.84 6.34 7.74 9.91 11.93 15.95 18.63 19.66 22.07 25.93 14.10 103.20 15.0 2.82 6.41 7.41 8.91 11.45 12.60 16.34 20.14 23.15 25.90 32.24 16.25 141.17 17.5 4.08 9.14 9.88 11.03 12.98 15.23 17.78 23.85 25.83 27.78 33.47 17.65 124.18 20.0 3.51 8.84 10.50 12.04 14.29 16.86 20.95 25.98 30.65 32.13 36.66 19.86 165.76 22.5 1.62 6.13 7.32 11.96 14.29 16.13 18.31 22.50 25.00 29.38 36.53 18.01 165.93 25.0 2.47 6.84 8.92 10.77 14.12 18.23 21.57 26.14 30.73 31.63 38.58 19.71 185.49 27.5 6.07 11.81 13.26 13.92 17.99 21.02 25.00 30.23 31.48 32.13 42.00 22.89 198.81 30.0 5.34 8.22 12.43 14.32 19.97 23.59 28.36 31.90 32.17 34.27 44.65 24.27 232.99 32.5 4.21 8.70 11.33 13.39 16.52 21.12 26.41 31.92 33.45 36.61 44.84 23.52 257.74 35.0 3.58 7.72 9.66 11.52 15.19 22.37 27.56 31.78 34.67 36.68 44.36 23.04 254.89 37.5 6.42 11.74 12.82 14.25 20.12 24.62 29.48 33.79 36.93 38.79 47.10 26.46 297.31 40.0 4.41 9.23 12.50 15.30 18.91 25.50 30.28 35.72 38.61 40.52 47.80 26.30 298.79 42.5 6.91 12.11 14.17 15.48 21.21 27.78 31.82 34.62 38.16 40.98 48.92 27.48 287.52 45.0 4.12 8.63 10.53 11.81 16.99 20.23 29.04 33.89 36.92 40.36 48.99 25.25 367.75 47.5 5.89 9.68 10.80 12.71 16.11 21.14 26.61 33.33 36.60 38.59 48.15 24.89 308.34 50.0 8.70 13.63 15.47 18.05 20.79 25.14 31.45 36.07 39.31 41.69 51.08 28.52 302.91 52.5 9.70 19.60 21.87 24.15 28.54 33.14 37.84 41.58 43.09 45.80 53.83 33.27 291.59 55.0 13.38 20.89 26.90 30.89 37.03 42.27 46.92 50.38 54.89 57.03 68.92 41.58 408.23 57.5 14.22 28.37 31.30 35.80 41.15 47.21 51.95 59.62 62.60 69.95 81.67 47.36 537.62 60.0 15.22 25.73 31.01 36.89 42.96 47.99 54.13 63.18 66.78 73.19 84.89 49.26 578.93 62.5 20.47 30.91 36.60 41.67 48.16 54.77 60.08 65.71 69.84 75.19 85.78 53.33 547.10 65.0 19.79 29.50 37.37 40.61 49.50 57.77 64.04 68.44 72.29 76.14 85.20 54.27 566.49 67.5 23.31 38.43 44.67 47.99 55.61 65.52 69.20 74.66 78.79 81.68 87.54 60.06 548.13 70.0 27.87 43.46 48.28 53.71 61.77 66.58 73.32 79.86 82.35 85.82 92.66 64.09 543.17 72.5 27.91 47.20 54.42 57.78 66.51 72.92 80.04 84.16 86.91 89.19 95.02 67.90 560.38 75.0 35.43 50.87 56.57 60.63 69.16 76.22 81.43 85.24 86.80 89.19 96.26 70.11 510.60 77.5 37.55 60.18 63.07 67.26 74.46 80.35 85.11 89.02 90.42 92.33 96.44 74.13 469.37 80.0 40.41 61.55 65.32 70.54 76.82 82.10 86.41 89.04 90.59 93.26 97.05 75.46 459.78 82.5 50.90 67.32 72.19 77.48 81.86 85.83 88.31 90.56 92.38 94.55 97.60 79.52 371.81 85.0 56.62 70.86 76.51 79.85 85.19 89.17 91.58 93.52 94.74 96.06 98.01 82.33 328.28 87.5 71.05 78.25 81.79 85.02 88.73 91.62 93.88 95.25 96.18 97.22 98.35 86.51 217.93 90.0 66.61 82.63 84.88 86.91 90.50 92.51 95.88 97.25 97.53 97.91 99.08 87.85 215.69 92.5 82.11 88.14 89.33 90.68 92.87 94.73 96.47 97.75 98.13 98.43 99.47 92.45 59.56 95.0 89.76 93.12 94.25 94.87 95.77 96.69 97.83 98.42 98.62 98.93 99.56 95.58 18.61 97.5 96.62 98.37 98.72 99.17 99.59 100.00 100.00 100.00 100.00 100.00 100.00 98.84 5.99 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 0 to 6 hours 2.5 0 0 0 0 0 0 0 0 0 0 0.78 0.43 3.17 

5.0 -- -- -- -- 2.69 3.63 4.57 -- -- -- -- 3.63 2.45 7.5 -- -- -- -- -- .53 -- -- -- -- -- .53 0 

10.0 -- .60 .65 .93 2.69 8.09 13.28 14.30 14.72 15.11 -- 7.90 42.59 12.5 -- -- -- -- 0 0 0 -- -- -- -- 0 0 15.0 -- -- 5.85 8.23 12.99 17.75 19.54 21.33 22.22 -- -- 15.27 47.73 17.5 -- -- 1.11 1.51 2.30 3.09 13.86 24.62 30.00 -- -- 11.40 173.61 20.0 -- -- -- -- 4.42 11.04 17.66 -- -- -- -- 11.04 121.86 22.5 -- .27 .68 1.08 3.36 6.38 19.23 29.79 32.79 35.78 -- 14.66 233.52 25.0 -- 0 0 0 3.19 7.98 9.86 16.67 25.00 33.33 -- 11.60 205.43 27.5 -- -- 1.70 1.80 2.01 2.22 11.20 20.19 24.68 -- -- 9.53 114.72 30.0 -- -- -- -- 8.47 19.88 31.29 -- -- -- -- 19.88 361.36 32.5 -- 2.01 2.19 2.50 5.41 8.13 15.82 26.63 27.61 30.31 -- 14.50 180.94 35.0 -- -- -- -- -- -- -- -- -- -- -- -- -- 37.5 -- 2.61 2.79 2.97 3.33 8.05 12.77 19.59 23.00 26.41 -- 11.28 92.34 40.0 -- -- 2.94 2.95 2.96 2.97 2.99 3.02 3.03 -- -- 2.98 0 42.5 -- -- -- -- -- -- -- -- -- -- -- -- -- 45.0 -- 4.83 4.98 5.02 5.69 7.11 16.00 28.37 29.16 31.46 -- 15.61 173.20 47.5 -- -- -- -- -- 26.41 -- -- -- -- -- 26.41 0 50.0 -- -- 6.62 10.23 17.46 24.69 27.79 30.88 32.43 -- -- 21.25 117.00 52.5 -- 1.58 3.96 6.34 7.99 8.08 10.89 15.58 19.80 24.03 -- 11.12 78.59 55.0 -- 8.96 9.35 9.74 16.00 25.00 33.33 40.06 41.83 43.59 -- 25.47 214.66 57.5 -- -- 13.13 13.28 13.57 13.86 19.75 25.63 28.57 -- -- 18.52 50.59 60.0 -- 2.79 6.99 11.18 16.46 20.20 23.53 27.19 29.37 31.54 -- 18.58 125.61 62.5 -- 10.23 14.73 18.56 24.37 29.07 33.10 36.04 37.06 40.53 -- 27.22 221.24 65.0 -- 2.16 7.29 12.42 22.69 32.56 42.42 43.49 44.02 44.55 -- 27.96 294.53 67.5 -- 24.51 31.15 35.79 39.19 42.42 45.89 47.17 48.12 48.74 -- 38.11 167.52 70.0 -- 15.05 18.44 18.55 22.77 27.06 37.75 52.99 55.21 62.19 -- 35.75 629.27 72.5 9.49 20.63 26.09 30.08 35.43 40.28 42.64 43.05 46.52 53.89 64.47 37.77 251.57 75.0 27.12 30.51 35.00 39.50 41.98 48.92 70.71 76.24 82.06 87.88 88.12 56.77 519.05 77.5 38.30 40.56 46.36 52.16 61.01 62.19 77.70 88.70 89.30 89.90 90.10 66.73 382.78 80.0 -- 33.71 38.77 44.22 57.11 61.13 67.36 87.97 90.95 91.02 -- 62.43 537.96 82.5 -- 20.74 34.56 42.44 56.07 63.33 73.67 85.66 91.92 91.98 -- 58.91 942.20 85.0 5.10 46.11 50.60 55.09 72.29 89.92 92.17 92.93 93.00 93.07 93.53 71.13 833.14 87.5 -- 36.71 44.85 52.07 63.89 67.90 87.92 93.01 93.07 95.41 -- 69.29 664.20 90.0 47.88 60.24 64.89 72.51 85.00 86.67 93.99 94.77 95.37 95.96 98.22 81.60 314.48 92.5 52.14 71.85 73.00 77.30 89.65 95.00 95.41 95.87 95.98 96.02 99.28 85.84 230.48 95.0 -- 86.87 87.98 89.51 94.64 96.54 96.98 97.02 97.77 98.81 -- 94.08 26.06 97.5 96.10 98.99 99.17 99.82 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.01 6.94 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 6 to 12 hours

2.5 0 0 0 0 0 0 1.85 3.82 4.88 7.13 16.20 3.95 42.03 5.0 1.66 2.95 3.00 4.21 4.94 7.00 11.40 20.84 22.79 23.92 24.53 11.36 81.34 7.5 1.87 3.57 3.77 4.49 10.46 15.12 22.18 24.07 24.09 25.00 25.50 14.53 98.07 

10.0 4.14 4.97 7.06 8.75 13.75 18.54 23.28 24.96 25.00 25.61 31.30 17.41 111.57 12.5 0 5.05 5.66 9.35 13.20 22.79 24.93 25.90 26.56 29.04 34.01 18.87 153.79 15.0 8.18 13.64 14.82 16.66 24.07 25.05 26.70 28.58 29.99 31.78 33.00 23.37 96.18 17.5 8.47 10.51 10.73 12.08 16.67 27.08 27.93 28.75 30.76 32.90 41.38 22.90 142.84 20.0 8.89 9.32 9.80 13.89 18.94 25.25 28.07 30.04 31.01 35.52 39.79 23.55 130.99 22.5 8.11 13.06 14.21 18.56 21.19 29.68 33.00 38.62 40.52 41.25 45.09 27.73 188.95 25.0 13.06 20.81 22.10 28.13 29.03 30.17 38.32 41.25 41.25 41.92 43.93 31.62 117.31 27.5 11.11 14.97 20.77 24.23 30.19 31.86 32.20 33.49 39.36 42.59 43.27 29.09 130.90 30.0 12.02 17.75 22.53 24.94 32.20 33.70 38.38 41.25 42.34 43.43 44.34 31.70 138.02 32.5 3.18 24.55 26.94 28.12 30.78 32.20 33.42 38.99 41.26 43.81 45.08 30.62 159.97 35.0 23.02 29.09 29.86 30.79 33.76 37.84 42.86 45.46 45.52 45.54 47.44 36.89 103.24 37.5 4.94 14.03 15.66 16.34 20.15 26.67 33.44 42.97 45.54 45.54 45.96 27.64 224.43 40.0 26.32 28.90 29.61 30.99 32.20 32.58 36.85 40.20 44.33 45.62 46.01 35.22 61.19 42.5 5.63 11.97 22.99 27.33 31.48 35.95 41.25 43.39 45.77 46.47 46.47 32.05 208.08 45.0 9.48 18.81 18.97 19.32 19.61 29.37 34.23 37.84 38.46 39.04 44.45 28.04 139.61 47.5 13.95 22.24 26.67 27.61 29.85 32.20 34.62 41.09 41.25 43.33 45.91 31.95 122.48 50.0 -- 14.76 22.54 24.19 29.92 42.95 43.73 44.61 45.06 45.62 -- 32.96 227.01 52.5 .48 13.92 14.40 19.66 28.91 31.02 32.20 32.86 35.52 41.51 46.06 26.91 200.79 55.0 7.85 16.76 20.64 24.84 25.73 27.62 36.37 39.44 44.88 47.24 48.80 30.41 180.45 57.5 2.17 8.83 16.25 20.07 29.33 31.37 33.90 41.75 44.60 45.35 56.94 30.10 314.45 60.0 4.96 14.44 16.54 18.15 28.43 35.59 35.59 40.54 42.85 44.53 55.84 30.78 258.04 62.5 1.66 10.36 18.68 19.05 19.77 26.92 36.76 37.65 38.24 42.87 66.66 29.12 363.43 65.0 2.94 5.91 6.46 12.77 29.49 33.43 38.95 63.04 73.05 75.77 79.93 38.03 789.14 67.5 4.03 19.03 19.89 26.09 29.84 39.74 41.53 41.53 43.14 43.14 45.54 33.66 318.26 70.0 3.22 7.17 9.40 18.07 22.90 36.59 45.75 48.31 48.31 49.66 62.38 33.26 526.44 72.5 4.39 18.92 25.00 27.18 31.16 42.31 44.93 52.48 52.54 52.54 81.21 38.97 511.38 75.0 12.21 21.93 30.49 33.33 36.08 48.02 54.24 54.24 54.24 55.02 61.21 43.01 446.46 77.5 15.97 33.33 37.82 39.04 44.14 45.67 47.52 54.24 54.24 54.24 59.73 44.20 332.77 80.0 38.58 43.98 45.71 46.70 48.81 50.15 54.37 58.47 59.32 59.96 66.73 50.51 197.86 82.5 34.41 48.28 50.30 50.50 58.26 60.17 61.97 68.40 71.74 74.95 84.06 59.24 344.59 85.0 33.86 48.82 51.84 53.41 70.45 74.66 79.28 80.21 80.51 83.79 91.00 67.12 487.39 87.5 40.17 51.93 52.53 54.07 69.91 81.21 83.51 84.75 86.62 89.74 92.39 70.53 461.23 90.0 24.69 49.22 56.89 58.25 72.31 86.42 90.75 93.35 94.44 95.07 98.31 73.29 654.24 92.5 41.72 61.65 69.44 73.26 80.20 89.74 93.11 95.22 95.96 96.42 99.44 79.42 460.71 95.0 38.15 69.52 74.78 83.60 89.35 95.82 96.69 97.35 97.83 98.18 100.00 83.73 455.87 97.5 67.78 93.87 96.57 97.48 98.83 100.00 100.00 100.00 100.00 100.00 100.00 92.86 251.56 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 12 to 24 hours 2.5 0 0 0 0 0 0.54 1.70 3.52 5.26 7.58 14.98 4.19 47.95 

5.0 1.52 2.45 2.87 3.24 5.12 6.92 7.65 13.56 13.87 18.08 19.82 9.01 56.46 7.5 1.90 3.33 4.36 5.22 6.87 7.37 8.05 10.86 15.57 18.99 21.58 10.55 91.41 

10.0 2.27 3.87 4.90 6.45 7.72 8.08 9.24 13.87 16.37 17.99 21.58 11.13 110.29 12.5 .23 3.65 4.90 7.23 8.07 8.99 10.16 14.54 16.39 19.09 21.58 11.99 128.93 15.0 1.30 3.54 4.65 4.93 5.97 7.96 10.50 17.21 17.62 19.11 24.61 11.98 149.64 17.5 .77 2.17 3.23 5.66 7.83 8.78 12.04 14.73 19.05 19.15 22.34 12.01 146.84 20.0 4.83 6.91 7.09 7.84 8.79 9.68 12.28 18.93 21.03 21.93 31.67 14.86 160.88 22.5 1.23 5.14 7.80 8.51 11.17 12.44 12.79 14.60 18.11 20.37 27.13 14.23 154.96 25.0 3.46 8.63 10.74 12.71 14.36 16.45 18.93 21.32 21.61 23.86 32.11 17.71 129.53 27.5 1.30 6.14 13.34 14.65 19.44 21.36 22.81 28.99 30.43 31.68 34.95 21.10 175.36 30.0 5.51 9.48 13.87 15.03 17.23 21.37 24.12 26.97 32.08 33.07 38.27 22.55 199.89 32.5 1.37 9.59 15.73 18.14 20.90 24.18 25.10 29.82 34.39 36.64 43.24 23.91 190.45 35.0 4.10 7.85 9.55 17.49 21.41 25.52 27.26 31.60 37.18 38.85 43.15 24.77 235.28 37.5 4.11 9.02 14.84 19.50 24.32 27.72 30.69 33.68 35.27 40.86 43.24 26.09 194.33 40.0 9.41 14.76 23.65 27.04 31.29 34.68 39.27 42.08 42.20 42.98 44.63 31.62 174.79 42.5 6.78 12.81 14.65 15.54 25.51 30.39 35.38 41.99 42.70 45.34 48.75 29.56 268.27 45.0 8.39 10.21 17.77 19.77 23.96 35.48 39.00 41.92 42.68 45.61 51.12 30.78 255.15 47.5 9.01 14.08 19.59 20.45 23.57 25.96 35.78 42.96 44.68 45.75 48.68 29.94 230.39 50.0 10.10 20.27 21.77 24.81 32.06 36.09 42.56 45.42 45.93 48.47 49.40 34.05 215.28 52.5 10.06 17.42 21.49 22.62 31.21 38.83 42.71 45.82 46.93 48.53 53.57 34.27 236.45 55.0 14.71 21.86 27.41 32.37 33.51 39.89 43.16 45.37 45.82 49.02 57.27 37.43 219.21 57.5 18.01 23.21 25.42 29.59 34.52 42.38 43.16 45.82 47.91 49.20 57.27 37.96 191.13 60.0 16.40 21.78 25.73 32.37 39.39 43.16 45.37 48.38 48.68 49.06 56.14 38.64 257.89 62.5 16.96 24.12 25.97 32.62 39.89 43.16 48.38 52.83 57.27 57.75 61.21 42.02 328.44 65.0 9.32 17.75 21.06 23.04 30.10 39.54 44.57 48.51 51.88 56.69 58.36 36.40 357.20 67.5 13.18 17.60 24.07 28.73 35.23 38.72 40.66 45.66 48.87 51.52 57.88 37.68 358.08 70.0 16.58 22.97 24.07 24.71 33.48 39.69 40.84 45.51 46.12 48.02 57.27 35.87 202.28 72.5 23.54 26.24 28.24 33.38 40.16 43.31 45.82 48.57 51.92 54.55 59.18 41.64 213.43 75.0 17.72 26.26 29.58 31.34 42.04 46.40 50.08 55.73 57.57 58.93 83.41 46.27 468.53 77.5 25.58 33.26 36.77 39.59 45.83 47.56 55.69 59.00 63.51 67.87 75.05 50.14 340.12 80.0 12.85 27.05 36.26 42.37 48.24 52.53 58.54 62.46 63.83 69.37 85.79 50.38 597.71 82.5 11.05 27.73 32.27 43.79 48.91 51.88 57.96 65.02 68.53 71.35 92.92 52.11 671.88 85.0 22.44 29.72 32.59 35.90 46.26 50.63 57.27 66.60 73.63 75.84 88.60 52.98 611.80 87.5 29.86 37.81 44.02 47.75 54.10 61.23 66.74 76.47 81.48 85.20 95.24 61.02 565.96 90.0 37.96 52.63 58.19 63.40 74.52 80.35 84.60 87.22 88.34 89.94 95.60 71.81 555.59 92.5 28.39 53.98 64.03 81.56 87.28 89.41 90.89 92.21 92.84 93.55 96.63 77.19 633.79 95.0 43.56 55.38 68.71 76.88 91.83 93.50 94.49 95.56 96.31 96.71 97.90 81.24 509.52 97.5 76.52 91.30 94.08 95.65 97.07 98.22 99.14 100.00 100.00 100.00 100.00 92.87 199.31 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 24 to 72 hours

2.5 0 0 0 0 0.76 1.99 4.01 6.46 7.79 9.45 13.13 4.74 37.55 5.0 1.35 3.17 3.67 4.63 6.39 7.92 13.16 15.77 21.04 22.83 29.92 12.66 119.60 7.5 2.80 5.60 6.44 6.84 7.79 11.00 14.49 17.90 24.76 29.03 33.19 15.16 144.79 

10.0 3.75 7.67 7.83 8.63 10.10 13.25 18.13 22.75 25.00 30.48 35.06 17.40 145.19 12.5 1.11 4.83 6.92 7.67 10.35 12.26 15.11 18.75 19.03 25.60 30.78 14.18 100.53 15.0 2.51 7.54 7.90 10.23 13.16 14.10 19.10 21.17 23.35 24.69 31.37 16.61 105.69 17.5 2.45 7.19 8.06 10.83 12.22 16.35 20.95 24.63 25.39 27.13 32.51 17.23 115.00 20.0 2.92 4.05 6.16 6.95 11.51 14.05 19.12 25.00 26.22 30.87 35.14 16.99 145.79 22.5 4.02 6.25 8.47 9.21 13.64 17.75 22.87 26.99 29.62 33.97 37.63 19.45 155.48 25.0 7.79 9.77 10.86 11.38 13.45 19.12 26.99 31.22 33.68 36.71 40.32 22.07 159.38 27.5 11.53 12.23 13.63 14.00 15.79 23.16 26.83 33.45 33.82 36.50 40.59 23.94 139.70 30.0 9.36 14.72 16.36 17.32 19.95 26.99 30.93 34.32 37.10 40.37 44.92 26.31 145.58 32.5 9.19 14.88 16.98 18.10 19.90 22.13 24.09 37.92 39.98 41.21 46.33 26.41 176.31 35.0 12.93 20.68 20.73 21.30 24.04 26.22 36.88 40.87 42.86 43.76 46.49 30.36 144.60 37.5 12.57 21.80 22.48 23.89 25.18 26.28 26.93 30.03 31.14 36.59 43.01 27.54 87.56 40.0 12.60 20.93 24.32 25.44 27.83 31.84 32.83 34.23 37.93 40.88 46.20 29.54 126.17 42.5 15.85 26.55 26.99 28.54 29.74 33.37 36.17 37.97 40.39 42.21 46.30 33.00 90.74 45.0 11.24 15.55 17.85 19.39 25.46 32.58 39.06 41.54 42.67 43.35 44.89 29.93 178.63 47.5 13.90 19.52 20.96 25.42 30.00 33.75 37.48 43.53 43.97 45.48 48.31 32.80 164.19 50.0 18.58 28.00 28.99 30.23 31.69 37.16 41.18 44.84 46.78 47.07 48.23 36.31 136.22 52.5 12.40 20.98 21.69 22.60 32.37 34.85 40.58 42.96 43.22 44.58 48.96 32.95 162.47 55.0 16.52 25.11 28.14 29.92 36.93 41.50 45.05 47.72 48.38 49.20 52.07 37.95 148.02 57.5 16.43 23.90 26.21 28.89 30.19 38.02 40.96 47.19 48.60 49.38 53.14 36.00 176.27 60.0 24.33 29.76 31.44 34.66 39.49 41.75 44.08 49.13 50.00 50.93 53.05 40.79 127.96 62.5 27.28 30.90 31.93 34.68 39.99 44.98 50.34 52.21 52.66 53.32 54.99 43.18 122.81 65.0 13.27 31.73 32.43 34.00 40.00 45.31 51.97 54.76 56.18 56.44 58.40 42.36 247.26 67.5 25.11 33.51 33.88 37.14 40.00 43.77 52.55 54.86 56.18 57.85 59.85 43.97 209.17 70.0 12.94 35.78 37.22 38.43 44.41 45.74 46.88 50.87 54.20 56.18 61.00 43.62 218.69 72.5 20.80 31.81 33.07 33.19 38.60 46.21 49.30 51.50 53.28 54.48 58.54 42.82 183.40 75.0 26.00 30.44 34.09 35.05 36.71 46.21 53.17 56.72 57.62 58.59 61.40 44.38 192.71 77.5 33.21 39.57 41.05 44.91 48.64 53.21 56.55 61.56 62.63 63.07 67.90 52.30 226.16 80.0 23.26 39.22 41.48 47.86 53.71 57.87 59.51 62.86 63.59 65.33 69.57 52.48 279.55 82.5 34.80 42.30 46.25 50.17 53.28 58.27 62.92 66.63 68.78 70.36 76.95 57.39 236.68 85.0 37.66 50.72 52.04 52.62 59.21 64.60 70.91 74.28 76.26 77.83 83.38 62.72 310.69 87.5 37.66 42.82 53.98 57.88 60.92 71.60 75.40 79.63 80.65 84.80 88.82 65.68 402.19 90.0 47.68 57.23 60.77 61.93 64.20 67.80 76.99 80.81 83.71 86.38 95.46 70.58 289.10 92.5 51.83 62.61 67.14 69.76 76.92 78.79 83.38 87.61 89.37 91.87 96.19 76.77 256.75 95.0 62.31 73.49 76.13 78.58 83.14 87.10 91.16 93.92 95.03 96.02 98.13 83.51 200.25 97.5 82.85 89.29 92.58 94.22 96.07 97.67 98.74 99.57 100.00 100.00 100.00 93.99 81.48 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Fourth-quartile storms; storm duration 0 to 72 hours 2.5 0 0 0 0 0 0.81 2.10 4.49 5.86 7.97 13.82 4.19 42.12 

5.0 1.55 2.86 3.24 3.73 5.18 7.25 11.28 13.88 18.02 19.89 24.21 10.88 89.76 7.5 2.26 3.83 4.95 5.94 7.37 8.60 12.29 17.90 20.36 24.05 31.25 13.34 122.35 

10.0 3.14 4.97 7.00 7.73 8.69 11.01 15.33 19.34 21.92 24.18 31.67 14.86 131.24 12.5 .91 4.26 5.66 7.35 9.13 10.87 14.80 19.42 21.58 25.37 30.91 14.53 134.79 15.0 2.59 5.89 7.54 8.03 11.18 14.56 18.72 21.98 24.07 26.10 31.60 16.54 132.24 17.5 1.43 4.89 7.83 8.16 10.94 13.40 19.12 23.58 25.60 27.84 32.16 16.50 149.14 20.0 3.90 6.91 7.77 8.83 10.69 14.58 20.51 24.22 26.39 30.38 35.31 17.81 157.47 22.5 3.34 6.93 8.58 9.88 12.70 16.01 21.19 26.82 29.05 33.58 38.31 19.47 190.04 25.0 7.50 10.22 11.36 12.53 15.10 19.12 21.98 26.99 30.11 33.60 40.32 21.19 167.06 27.5 3.72 12.22 13.64 14.57 19.85 22.33 26.99 31.13 32.64 33.75 40.59 23.13 166.49 30.0 8.84 13.87 15.72 16.85 21.33 25.89 31.77 33.70 36.99 38.89 43.68 26.14 178.41 32.5 4.91 11.52 16.00 18.25 20.38 24.09 27.78 34.34 37.51 40.42 45.02 25.35 192.76 35.0 8.99 19.51 20.69 21.41 25.17 28.58 33.85 39.13 41.25 43.56 45.61 29.19 195.37 37.5 6.86 13.00 16.05 21.51 24.13 26.59 29.47 31.48 35.44 41.04 45.40 26.33 169.98 40.0 10.77 19.86 24.90 27.04 29.85 32.15 34.61 39.16 41.10 42.44 45.22 30.66 158.87 42.5 11.30 15.00 24.74 26.52 29.05 31.63 36.08 40.80 42.08 44.43 46.81 31.28 189.96 45.0 8.14 13.49 17.58 19.03 24.14 31.41 38.01 40.39 41.78 42.94 46.69 29.09 217.03 47.5 11.22 19.47 20.62 21.25 26.33 31.94 36.23 42.46 43.97 45.38 48.48 31.22 192.25 50.0 11.93 21.71 25.00 27.28 31.61 36.87 41.95 45.01 45.82 47.02 48.68 34.35 193.68 52.5 9.51 16.13 20.97 21.89 29.18 33.37 39.89 43.10 45.37 45.82 49.15 32.12 228.21 55.0 14.47 24.64 25.49 28.14 33.25 39.67 43.16 45.37 47.32 48.64 52.53 36.42 199.00 57.5 16.02 21.71 25.36 28.47 30.41 38.02 42.70 45.49 46.93 49.11 55.35 35.42 216.45 60.0 16.47 23.82 27.91 31.44 35.59 40.21 43.91 47.52 48.64 49.60 53.01 37.92 216.54 62.5 18.13 25.99 29.41 31.75 37.48 42.36 45.82 51.67 52.53 53.72 57.69 40.12 264.70 65.0 8.80 21.09 23.53 27.73 34.85 40.12 45.82 52.83 55.22 56.57 58.46 38.74 363.31 67.5 13.56 25.71 29.11 33.54 37.61 40.02 43.29 48.60 50.84 54.58 58.48 39.53 295.36 70.0 11.67 21.68 24.10 28.48 37.22 41.32 45.81 47.60 48.74 51.96 58.54 38.44 322.19 72.5 20.01 26.56 29.98 33.07 38.82 42.97 46.36 49.90 52.54 53.46 58.35 41.36 254.86 75.0 23.12 29.12 31.49 34.24 38.10 46.97 52.90 55.56 57.34 58.36 62.19 45.53 365.92 77.5 29.83 36.72 39.47 41.87 45.91 49.02 54.61 58.08 61.56 63.06 73.16 50.63 322.87 80.0 21.67 39.68 42.37 45.87 49.16 55.02 58.47 61.81 63.49 65.15 72.47 51.65 372.50 82.5 27.68 39.97 45.83 48.76 51.77 58.01 61.85 66.58 69.12 71.45 80.81 55.96 446.43 85.0 29.23 37.66 45.63 49.34 53.29 59.95 70.78 75.33 77.37 80.28 88.22 59.93 517.68 87.5 33.26 42.33 49.42 52.55 59.56 66.48 75.37 81.08 83.71 85.48 92.25 64.74 500.25 90.0 40.88 54.97 59.45 61.99 68.54 77.14 83.27 87.11 89.10 91.32 96.05 72.04 475.38 92.5 45.48 61.17 67.67 72.27 80.26 86.54 89.72 92.12 93.21 94.60 97.12 77.71 451.44 95.0 52.30 69.29 74.78 78.73 87.17 92.08 94.01 95.66 96.39 96.95 98.38 82.79 368.61 97.5 80.12 90.91 94.13 95.57 97.28 98.47 99.41 100.00 100.00 100.00 100.00 93.52 159.54 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 0 to 6 hours

2.5 0 0 0 0 0 0 0 0 0 0 4.99 1.66 31.64 5.0 1.86 3.98 4.31 5.49 9.00 12.73 18.20 20.39 23.05 25.32 36.68 16.13 192.19 7.5 2.00 5.09 6.02 8.03 10.83 14.75 17.76 25.76 28.81 32.87 44.97 19.15 271.46 

10.0 2.72 6.52 7.94 11.28 16.71 20.70 27.63 34.83 38.12 45.12 55.46 25.52 384.37 12.5 2.15 9.50 13.55 14.55 21.27 27.98 34.60 38.23 43.23 50.80 63.04 30.50 487.55 15.0 6.96 15.16 18.40 20.59 32.15 36.17 39.78 50.10 53.60 60.00 72.05 37.71 524.31 17.5 8.80 16.52 17.65 20.78 26.38 40.31 48.25 60.68 64.74 68.37 76.89 41.04 644.73 20.0 12.49 19.89 22.14 25.50 32.35 43.40 53.63 63.42 67.17 71.55 82.04 44.76 675.73 22.5 6.94 17.88 19.63 23.73 33.17 45.56 60.37 67.90 75.22 77.02 86.29 46.63 860.28 25.0 7.98 20.55 25.26 32.00 39.86 49.25 58.85 71.05 76.87 77.84 85.50 48.83 783.10 27.5 10.37 24.17 26.85 30.83 42.43 52.17 59.95 67.50 70.27 76.84 84.15 49.41 684.40 30.0 17.56 31.43 38.84 45.13 54.95 62.67 73.15 77.03 81.48 84.35 89.14 58.49 697.45 32.5 13.25 28.19 33.10 37.10 48.20 57.97 68.18 75.16 78.74 82.31 87.81 54.50 733.66 35.0 15.43 41.53 50.33 54.14 61.43 66.96 77.98 82.34 86.62 87.56 92.39 63.67 704.05 37.5 22.96 34.07 38.93 43.65 54.21 65.27 74.70 81.86 84.83 88.03 92.48 60.53 706.19 40.0 23.62 43.99 51.41 57.34 67.26 76.56 81.15 85.98 88.25 89.15 93.26 66.76 737.26 42.5 24.77 40.86 49.59 54.51 64.99 72.45 79.18 86.20 88.31 89.03 94.09 66.15 655.39 45.0 19.80 38.80 46.23 60.38 73.73 78.96 80.79 84.94 89.13 90.72 94.39 67.14 775.62 47.5 23.05 41.25 55.99 60.78 68.59 79.48 82.99 87.97 89.15 90.33 94.99 68.42 683.68 50.0 32.00 44.17 53.87 60.61 70.44 75.10 84.29 87.12 89.60 90.88 94.22 69.48 579.90 52.5 21.72 44.48 54.55 60.60 72.86 80.34 83.14 87.78 90.29 92.44 96.34 69.18 736.21 55.0 40.63 55.36 58.33 62.99 73.83 83.51 87.94 90.97 92.89 93.88 96.36 74.04 528.12 57.5 40.39 50.00 60.47 67.30 75.20 82.52 85.71 88.49 90.68 92.37 96.36 73.62 513.72 60.0 33.89 56.57 65.26 74.34 82.15 85.19 88.35 92.39 93.75 94.48 96.81 75.52 648.07 62.5 31.42 58.08 64.28 70.43 77.21 86.05 88.80 91.19 92.89 93.43 97.13 75.05 619.75 65.0 36.60 62.21 67.62 70.01 76.40 86.23 89.93 93.77 94.56 96.28 97.47 76.00 654.14 67.5 48.81 68.06 69.73 73.82 78.77 87.69 90.80 92.96 94.07 95.00 97.42 79.18 409.33 70.0 28.27 69.52 74.65 77.58 84.94 89.40 93.21 94.32 94.76 95.51 97.84 79.87 546.04 72.5 43.05 69.30 76.54 82.57 87.15 91.75 93.52 94.77 95.20 96.09 97.92 82.17 415.60 75.0 55.09 73.47 77.79 80.28 85.71 90.79 94.33 96.00 96.51 96.94 98.08 84.17 283.77 77.5 68.14 81.82 83.67 85.54 90.27 91.72 93.71 95.69 96.78 97.74 98.86 87.58 179.69 80.0 72.10 85.83 87.21 88.98 91.42 93.83 95.65 96.93 97.14 98.25 99.24 89.81 152.62 82.5 74.94 85.86 88.16 89.18 92.06 94.83 96.37 97.19 97.60 98.26 99.18 89.62 226.15 85.0 78.30 86.34 91.09 93.08 95.10 96.59 97.79 98.19 98.48 98.72 99.11 91.66 192.97 87.5 85.83 92.26 93.17 94.48 95.44 96.70 98.03 98.52 98.66 98.83 99.40 93.41 134.21 90.0 87.88 92.20 93.70 94.58 95.92 96.96 98.20 98.84 98.98 99.15 99.59 94.55 70.90 92.5 91.45 95.32 95.75 96.63 97.47 98.33 98.63 99.11 99.40 99.61 100.00 95.90 58.22 95.0 94.43 96.12 97.05 97.37 97.85 98.37 99.09 99.25 99.37 99.56 100.00 97.41 11.03 97.5 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 99.89 .59 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 6 to 12 hours 2.5 0 0 0 0 0 0 1.56 3.92 5.76 8.92 17.70 4.95 78.96 

5.0 2.19 3.48 4.44 5.72 8.42 13.14 19.42 24.09 26.50 31.64 46.43 18.68 317.20 7.5 3.20 5.99 8.30 10.87 14.64 20.69 27.12 32.32 36.53 41.41 54.32 25.14 425.26 

10.0 4.86 9.05 11.12 13.93 20.70 26.02 32.82 40.47 48.07 54.16 73.22 32.05 604.67 12.5 5.60 11.29 12.85 14.81 21.24 29.72 34.51 42.92 50.37 57.39 79.66 34.27 678.15 15.0 7.35 16.06 17.61 21.11 30.31 34.51 42.32 49.85 57.06 61.70 82.60 39.38 669.87 17.5 8.34 13.12 17.11 20.85 28.11 38.26 44.82 52.83 58.51 62.97 80.25 39.95 671.75 20.0 10.01 15.12 19.42 23.94 30.99 39.37 46.89 61.82 66.81 69.59 85.86 43.41 751.85 22.5 10.47 14.77 17.63 21.16 29.34 37.52 46.52 59.10 66.13 71.07 83.46 42.51 765.95 25.0 11.40 21.26 28.81 30.80 37.89 44.84 56.20 63.84 70.46 74.37 85.42 47.95 705.01 27.5 14.17 22.61 30.88 32.20 41.29 50.26 60.32 67.80 71.31 79.32 88.71 50.86 734.90 30.0 12.19 23.12 31.73 32.72 43.43 48.98 61.28 72.53 74.80 80.74 88.86 51.61 762.37 32.5 13.54 23.09 32.20 34.31 44.84 52.26 65.60 74.26 79.14 82.27 88.47 52.55 797.09 35.0 15.65 27.28 32.41 34.73 44.56 53.76 65.48 75.17 79.92 83.34 92.48 54.34 771.20 37.5 14.65 21.39 26.63 32.66 44.61 52.79 66.85 77.80 81.70 84.72 90.07 53.46 841.26 40.0 21.13 31.60 33.93 38.49 47.25 54.58 66.84 77.26 80.93 84.63 91.20 56.86 691.38 42.5 15.48 29.50 34.99 40.84 51.37 61.08 70.46 77.52 81.21 84.38 91.33 57.62 744.15 45.0 13.81 26.78 34.11 41.17 51.76 59.97 75.16 80.57 84.00 86.34 91.87 57.66 855.41 47.5 14.52 24.37 31.56 35.48 48.93 61.38 70.43 80.15 84.44 88.12 93.24 57.15 877.79 50.0 16.46 33.41 40.66 46.88 60.23 70.27 76.56 80.70 83.16 86.09 92.27 61.51 732.19 52.5 14.97 29.09 33.17 38.92 54.25 63.14 75.40 81.13 84.00 88.64 95.19 59.38 845.53 55.0 25.31 34.29 38.54 46.99 55.44 67.66 76.96 82.81 84.50 88.45 93.95 62.20 723.23 57.5 16.44 31.36 36.62 41.37 54.49 68.42 78.70 83.73 86.31 88.66 95.89 60.79 847.06 60.0 18.50 35.59 42.78 48.27 59.67 67.95 75.31 84.00 86.80 89.98 95.26 63.16 732.86 62.5 28.38 37.27 45.47 50.07 63.82 73.65 81.66 87.43 89.84 91.30 97.10 66.56 710.34 65.0 30.76 46.19 58.29 62.96 72.01 77.04 81.18 85.88 88.30 91.68 96.53 69.69 626.97 67.5 29.50 44.07 47.70 55.05 68.25 77.99 81.70 87.54 89.87 91.68 96.98 68.81 651.37 70.0 24.92 45.69 49.11 55.50 66.25 78.35 82.96 88.92 90.75 93.27 97.62 68.65 713.27 72.5 27.43 52.49 57.77 64.70 75.70 82.39 86.00 89.82 90.99 93.71 98.03 72.59 634.68 75.0 33.33 52.90 56.54 66.20 77.63 82.82 87.04 91.14 92.16 93.71 98.50 73.51 627.95 77.5 39.89 54.24 59.93 65.29 78.17 84.39 88.99 92.18 93.31 94.00 98.23 75.69 510.43 80.0 45.88 58.11 63.51 68.76 80.02 85.71 88.76 92.21 93.77 95.12 98.27 76.96 454.48 82.5 50.30 62.13 70.31 76.87 83.03 88.62 90.82 94.46 95.52 96.45 98.63 80.66 396.83 85.0 53.34 75.71 79.36 81.17 87.92 91.48 93.44 95.72 96.82 98.01 98.95 84.21 337.95 87.5 62.36 82.67 84.43 86.76 90.06 93.24 95.08 96.73 97.33 98.12 99.47 87.15 270.55 90.0 58.90 86.18 88.51 90.69 93.31 95.08 96.64 97.73 98.01 98.31 99.49 88.09 312.30 92.5 74.15 88.21 90.99 92.54 94.56 96.12 97.29 98.13 98.43 98.92 100.00 90.78 204.52 95.0 83.83 92.71 94.84 95.82 96.96 97.83 98.43 98.96 99.21 99.30 100.00 93.14 182.06 97.5 96.79 98.93 99.46 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 97.99 65.03 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 12 to 24 hours

2.5 0 0 0 0 0.47 1.73 3.95 6.69 8.67 11.38 18.61 6.42 107.40 5.0 2.32 4.72 6.52 8.00 13.15 17.19 20.33 25.39 28.94 33.68 48.27 20.94 346.56 7.5 4.61 8.05 9.96 13.01 21.58 27.10 31.67 38.55 43.39 47.70 58.95 29.24 449.31 

10.0 6.59 11.03 13.87 17.86 26.32 34.74 38.85 48.91 52.90 58.66 69.98 35.78 579.41 12.5 8.14 15.27 19.58 22.03 33.06 39.33 44.18 52.13 58.49 65.24 78.04 40.79 651.97 15.0 10.09 19.33 23.44 27.21 37.91 45.71 51.28 56.84 64.19 70.60 82.08 45.05 678.32 17.5 9.72 19.88 27.51 33.34 42.02 50.72 55.08 60.79 66.05 71.84 82.02 47.49 686.84 20.0 9.30 21.58 29.56 39.32 47.50 53.59 58.62 63.33 70.27 75.56 84.18 50.34 686.01 22.5 12.24 23.40 32.09 43.92 52.42 57.80 63.85 67.58 71.35 76.87 85.95 52.97 685.04 25.0 13.28 20.73 25.35 32.13 46.05 57.14 67.82 71.81 73.74 76.76 86.71 52.10 767.97 27.5 13.13 23.19 30.49 34.91 49.70 59.44 71.68 78.47 80.35 82.01 87.46 54.91 813.77 30.0 14.12 27.69 34.60 40.59 52.59 63.37 74.75 82.43 83.59 85.20 89.61 57.85 821.90 32.5 13.91 24.87 31.06 38.00 50.66 58.62 73.73 85.35 87.29 89.43 92.27 57.57 891.21 35.0 12.50 27.20 34.85 42.22 54.88 62.37 74.01 87.20 90.09 93.02 95.27 59.99 911.10 37.5 13.15 26.42 31.23 36.04 50.97 58.87 72.70 81.52 86.47 90.14 95.53 57.35 901.08 40.0 14.42 28.32 34.62 39.48 49.75 58.33 70.12 80.06 86.60 90.20 96.00 57.93 867.05 42.5 15.54 31.02 36.11 41.72 52.02 59.58 71.46 79.54 86.66 91.77 95.52 59.08 819.60 45.0 19.06 34.07 39.18 43.92 54.71 64.90 76.27 81.40 88.38 92.22 96.43 61.66 814.62 47.5 16.22 27.90 39.22 44.84 53.42 62.50 73.95 81.63 86.79 91.64 96.26 60.12 842.81 50.0 18.71 32.70 38.94 44.00 52.82 64.80 72.57 81.09 85.18 90.41 96.26 60.10 802.03 52.5 19.79 31.14 39.89 44.89 54.73 63.67 76.81 85.42 89.35 93.14 97.10 61.96 838.40 55.0 20.55 33.40 40.04 43.35 55.12 62.37 72.26 81.40 85.63 89.94 94.80 60.84 743.02 57.5 24.03 39.53 43.27 48.95 59.00 63.59 74.20 83.44 89.54 91.67 96.95 63.69 691.15 60.0 24.69 42.04 46.66 50.92 61.93 72.31 82.28 88.80 91.75 93.30 97.18 66.88 713.68 62.5 32.44 47.12 51.99 57.31 62.52 72.91 80.65 87.32 91.15 93.44 97.25 68.96 580.13 65.0 30.98 46.24 55.94 59.64 69.10 78.27 82.64 88.86 93.27 94.51 97.78 70.45 637.45 67.5 33.65 48.55 52.90 60.42 70.11 77.55 84.41 90.77 93.25 94.59 97.79 71.14 615.11 70.0 35.79 45.83 51.77 58.43 69.60 77.06 83.50 87.74 90.87 93.72 97.53 70.59 567.33 72.5 39.83 51.35 55.84 61.19 69.95 78.57 83.87 89.81 94.19 95.76 98.12 72.52 540.86 75.0 42.03 55.65 60.26 65.20 73.72 81.73 85.54 89.98 93.52 95.00 98.24 74.71 490.81 77.5 45.83 61.67 66.15 70.29 77.29 84.34 88.00 91.93 94.26 96.25 98.66 77.58 417.19 80.0 48.68 62.46 67.23 71.26 79.66 86.15 89.12 92.54 94.67 96.06 98.11 78.27 449.09 82.5 49.00 64.28 69.59 73.64 81.04 87.61 91.15 94.63 96.18 97.17 98.88 79.56 471.63 85.0 43.68 64.13 71.86 75.18 81.28 86.15 90.92 94.28 95.92 97.02 98.54 78.89 479.01 87.5 50.92 71.08 77.64 81.55 87.90 90.09 92.51 95.49 97.03 97.69 99.24 82.77 393.27 90.0 61.05 79.52 82.58 84.89 89.52 91.67 94.80 97.17 97.87 98.24 99.35 85.90 328.58 92.5 65.86 85.17 87.73 89.39 91.89 92.86 94.61 97.19 97.99 98.50 99.26 87.68 324.35 95.0 67.38 86.62 89.77 92.13 94.22 95.36 96.68 97.86 98.54 98.80 99.68 89.32 273.97 97.5 90.49 96.67 97.49 98.23 99.45 100.00 100.00 100.00 100.00 100.00 100.00 96.56 82.86 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 24 to 72 hours 2.5 0 0 0 0 1.58 3.42 5.64 8.96 12.01 16.11 29.06 9.28 203.46 

5.0 2.36 5.03 6.05 7.18 11.06 14.95 21.02 26.56 33.74 39.69 50.67 21.99 431.74 7.5 4.01 7.67 9.31 11.56 15.76 22.33 30.57 37.67 42.77 48.66 62.02 28.15 520.11 

10.0 5.18 9.35 11.32 13.06 18.09 26.48 35.48 46.58 53.01 57.73 69.94 33.33 676.02 12.5 4.84 10.04 11.92 15.22 21.10 32.09 41.77 56.77 64.68 69.99 81.42 38.37 853.30 15.0 6.73 10.81 12.55 14.89 23.09 31.45 43.21 54.01 60.02 69.68 83.42 38.55 841.79 17.5 6.19 12.00 14.35 16.86 25.00 30.37 40.72 55.56 62.35 69.18 83.17 39.18 835.79 20.0 6.27 13.04 15.55 19.09 26.15 34.81 46.94 61.70 69.19 75.39 86.12 41.87 884.19 22.5 5.56 12.08 16.25 19.62 26.71 36.09 45.79 56.92 61.86 73.66 86.71 41.08 867.28 25.0 7.96 12.31 16.34 21.26 27.83 35.62 47.33 58.28 62.45 72.90 85.76 42.04 840.33 27.5 9.76 13.41 16.51 20.40 30.06 34.66 46.54 60.50 63.60 74.88 87.46 42.45 842.21 30.0 9.82 18.94 22.10 27.01 32.13 36.81 45.76 59.41 63.41 69.05 87.36 43.69 735.29 32.5 10.25 16.85 20.04 23.09 33.71 39.11 46.52 54.81 59.08 64.01 82.59 42.37 683.65 35.0 11.03 20.04 23.66 28.02 36.81 43.66 51.31 61.34 63.18 65.49 84.66 45.46 690.98 37.5 12.73 20.26 25.06 28.65 38.10 48.42 59.49 64.66 66.13 68.76 81.55 47.54 673.51 40.0 13.61 22.52 25.88 31.04 39.03 47.56 60.20 67.63 69.38 73.42 84.06 48.98 690.59 42.5 18.75 27.24 29.05 31.12 38.00 43.73 57.42 69.07 71.20 76.02 87.72 50.15 663.34 45.0 13.63 25.23 30.17 36.53 43.02 46.93 57.99 69.96 72.41 78.56 91.47 51.39 743.08 47.5 12.73 21.51 29.90 35.11 43.57 50.76 58.45 68.86 72.37 80.65 91.15 51.20 770.84 50.0 16.93 23.47 29.15 34.05 43.73 53.75 62.57 71.54 75.92 79.07 90.32 53.06 741.33 52.5 21.73 32.12 36.36 40.00 44.48 54.89 61.84 68.75 72.66 77.73 88.92 54.43 611.64 55.0 28.38 41.87 44.26 47.64 52.08 58.73 64.39 75.70 78.66 82.97 90.53 59.68 533.09 57.5 28.89 43.67 48.20 50.26 59.34 64.19 72.53 79.27 82.86 84.47 91.70 63.03 557.67 60.0 29.52 42.37 44.21 49.01 54.24 63.91 73.56 81.81 84.31 86.69 93.98 63.17 575.42 62.5 28.73 44.65 50.98 54.07 62.02 67.68 75.22 84.50 87.08 91.58 95.59 65.74 595.01 65.0 22.51 39.49 45.87 51.39 61.09 67.14 76.12 83.86 87.18 91.84 97.34 64.42 689.07 67.5 28.62 42.42 46.66 53.59 61.54 68.77 76.63 84.22 86.75 89.07 96.99 65.88 605.14 70.0 34.55 46.21 50.66 57.11 64.32 71.69 81.04 89.19 91.37 94.53 98.54 69.27 608.47 72.5 31.67 49.26 53.28 58.76 70.18 77.27 82.84 89.19 92.18 94.41 98.23 71.15 586.56 75.0 33.96 49.38 54.77 57.42 63.94 74.58 81.77 89.19 91.75 94.60 98.54 70.10 580.30 77.5 35.42 53.52 57.85 62.22 69.22 77.57 84.89 90.65 93.13 95.76 98.21 72.36 560.50 80.0 35.54 50.67 57.87 60.96 66.10 74.46 80.16 89.32 92.61 94.47 98.42 70.55 579.83 82.5 42.12 55.46 61.27 65.36 71.31 78.92 84.09 89.54 93.38 94.99 98.04 74.23 454.18 85.0 45.79 63.38 67.73 70.93 76.95 82.40 88.08 92.27 94.60 96.39 98.53 77.85 402.12 87.5 52.55 68.85 72.41 75.30 80.00 84.25 87.79 94.19 95.32 97.06 98.59 79.94 357.98 90.0 54.61 65.12 70.87 76.36 82.26 85.03 88.37 94.45 96.37 97.54 98.91 80.90 315.54 92.5 67.27 77.63 80.64 82.98 86.69 89.72 92.51 95.49 96.89 98.03 99.15 86.34 177.17 95.0 77.56 84.88 87.32 89.71 92.63 94.76 96.15 97.56 98.19 98.81 99.58 90.81 117.15 97.5 89.92 95.02 96.25 97.22 98.42 99.31 100.00 100.00 100.00 100.00 100.00 96.82 33.20 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
First- through fourth-quartile storms combined; storm duration 0 to 72 hours

2.5 0 0 0 0 0 1.21 3.38 6.13 7.98 11.11 21.12 6.62 133.17 5.0 2.27 4.36 5.88 7.19 11.02 15.40 20.00 25.00 29.31 34.55 47.95 20.65 366.79 7.5 3.99 7.29 9.02 11.41 16.36 23.65 29.59 36.40 40.95 45.81 58.43 27.42 463.80 

10.0 5.36 9.30 11.93 14.78 20.81 29.41 36.33 45.37 51.07 55.65 69.20 33.27 604.11 12.5 6.17 11.90 14.56 18.07 25.00 34.53 41.16 51.48 58.10 64.93 79.30 37.98 718.33 15.0 7.79 13.90 17.75 21.64 30.75 38.79 47.18 54.80 60.00 67.65 81.82 41.30 727.21 17.5 8.33 14.67 18.96 23.01 32.13 41.67 50.87 58.48 62.83 68.98 81.82 42.90 739.69 20.0 9.07 16.41 21.22 25.10 35.03 45.92 55.20 62.56 67.97 73.83 83.90 45.85 770.94 22.5 7.81 16.34 20.70 25.00 36.49 47.92 57.10 65.29 69.44 75.33 85.43 46.65 804.41 25.0 9.47 18.86 23.16 27.62 37.17 48.48 58.73 69.13 72.61 76.04 85.88 47.99 796.36 27.5 11.44 20.08 24.71 30.41 37.62 51.03 60.77 71.35 77.31 80.00 87.37 49.86 817.74 30.0 12.87 23.55 29.32 32.64 41.19 52.44 63.29 74.37 79.73 83.33 88.55 52.21 807.70 32.5 11.86 21.33 27.22 32.96 41.34 51.39 59.82 73.02 78.37 83.45 90.69 51.65 826.91 35.0 12.26 24.73 29.89 35.35 44.84 55.46 63.18 74.22 79.99 86.43 93.88 54.08 836.02 37.5 13.84 24.06 28.34 33.78 45.06 54.58 64.60 74.16 78.46 83.52 92.27 53.74 815.56 40.0 15.72 27.42 32.06 37.04 47.26 57.42 67.25 76.03 80.07 85.12 93.17 55.74 792.10 42.5 18.76 29.10 32.96 37.52 46.30 57.41 68.43 76.46 79.68 85.76 94.14 56.60 760.70 45.0 15.29 30.26 36.63 40.83 49.35 60.66 71.73 79.56 82.23 87.93 95.00 58.20 823.17 47.5 14.07 26.41 34.55 40.68 50.00 59.35 68.82 79.48 83.05 86.96 95.33 57.27 837.19 50.0 18.71 30.94 36.93 42.68 52.60 62.96 71.79 79.38 83.33 86.96 94.59 59.22 767.45 52.5 20.96 31.86 37.85 42.37 52.60 61.51 71.53 80.77 84.41 88.40 96.14 59.63 772.68 55.0 25.00 39.67 43.67 47.86 56.05 63.41 73.01 81.25 84.95 88.45 94.35 62.23 658.01 57.5 25.56 40.33 45.46 49.69 59.39 67.71 75.66 83.32 85.67 89.12 95.30 63.88 664.96 60.0 25.93 42.20 45.82 50.66 61.75 70.76 80.13 85.61 89.02 91.60 95.92 65.90 675.41 62.5 29.74 45.39 51.65 55.63 63.44 72.67 79.88 87.37 89.78 92.55 96.39 67.98 622.01 65.0 26.09 44.40 51.44 57.69 66.26 74.64 80.71 86.97 90.38 93.49 97.39 68.33 669.39 67.5 33.39 46.67 52.92 58.48 68.63 76.75 82.76 88.28 91.43 93.49 97.27 70.15 607.52 70.0 33.94 46.85 53.17 59.94 68.72 77.39 83.95 89.19 92.35 94.25 97.92 70.60 621.88 72.5 33.87 51.24 56.76 62.76 73.00 81.36 86.20 91.03 93.63 95.13 98.05 73.16 573.28 75.0 36.11 54.24 57.88 61.96 73.28 81.06 86.09 91.07 93.43 95.62 98.29 73.70 547.01 77.5 41.58 57.63 62.62 67.53 77.35 84.14 88.74 92.64 93.98 95.93 98.52 76.33 482.64 80.0 43.25 59.07 63.40 67.02 76.32 84.39 88.74 92.82 94.40 96.14 98.47 76.39 498.28 82.5 48.70 62.12 67.53 72.19 80.23 85.88 90.21 94.21 95.66 96.98 98.63 78.84 445.40 85.0 49.97 67.44 72.08 76.13 81.77 87.78 91.92 95.07 96.32 97.47 98.73 80.52 415.44 87.5 54.57 72.66 77.33 81.00 86.25 89.91 93.69 95.70 97.11 97.82 99.22 83.35 351.42 90.0 59.59 76.44 80.54 83.23 87.69 91.64 95.03 97.15 97.83 98.28 99.27 85.23 313.24 92.5 70.25 82.42 85.49 88.16 91.21 93.48 95.67 97.47 98.17 98.65 99.50 88.41 228.92 95.0 75.57 87.32 89.96 91.91 94.33 95.82 97.26 98.19 98.66 99.10 99.67 91.00 182.48 97.5 92.49 97.11 98.03 98.71 99.66 100.00 100.00 100.00 100.00 100.00 100.00 97.35 52.34 

Supplement 3. Trimmed percentiles and statistics for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval

Percentile Average

(percent)

Variance(percent

10th 20th 25th 30th 40th 50th 60th 70th 75th 80th 90th
Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86. [The interval is the center of the percent-of-storm-duration interval; --, no data] Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 

First-quartile storms; storm duration 0 to 6 hours 2.5 1.33 2.20 2.50 2.78 3.95 6.07 7.82 10.00 10.51 

5.0 4.51 7.39 8.36 9.41 11.38 13.71 16.17 19.55 21.10 7.5 7.84 12.62 14.58 15.99 18.70 21.25 24.50 28.97 31.43 

10.0 11.55 17.96 20.62 22.43 25.94 29.17 33.13 38.46 41.51 12.5 15.66 23.31 26.49 28.65 32.89 36.90 41.54 47.36 50.90 15.0 20.18 28.76 32.24 34.68 39.60 44.38 49.73 55.57 59.32 17.5 24.66 33.81 37.57 40.34 45.81 51.37 57.13 62.71 66.23 20.0 29.24 38.66 42.58 45.54 51.52 57.78 63.77 68.80 71.97 22.5 33.42 43.19 47.24 50.27 56.67 63.05 69.29 73.69 76.44 25.0 37.62 47.66 51.71 54.75 61.34 67.46 73.79 77.60 79.74 27.5 41.25 51.38 55.48 58.61 65.27 71.18 77.23 80.64 82.27 30.0 44.61 54.82 58.92 61.99 68.67 74.48 80.25 83.17 84.51 32.5 47.80 58.07 62.14 65.21 71.68 77.30 82.57 85.14 86.38 35.0 51.00 60.99 65.02 68.10 74.30 79.97 84.61 86.90 88.10 37.5 53.59 63.26 67.37 70.49 76.40 82.48 86.33 88.41 89.66 40.0 56.29 65.62 69.76 72.76 78.35 84.49 87.78 89.71 91.02 42.5 58.92 67.80 71.94 74.96 80.08 85.86 88.72 90.58 91.92 45.0 61.51 69.61 73.87 76.97 81.62 87.02 89.63 91.42 92.65 47.5 63.53 71.38 75.65 78.77 82.85 87.85 90.28 92.02 93.19 50.0 65.87 73.19 77.46 80.58 84.19 88.53 91.00 92.66 93.72 52.5 67.84 74.75 78.90 82.01 85.36 89.17 91.61 93.17 94.21 55.0 69.63 76.23 80.32 83.26 86.50 89.86 92.23 93.72 94.74 57.5 70.72 77.74 81.72 84.38 87.54 90.52 92.78 94.18 95.23 60.0 72.03 79.18 83.09 85.56 88.68 91.26 93.36 94.67 95.69 62.5 72.61 80.44 84.23 86.55 89.66 91.88 93.81 95.07 96.08 65.0 73.24 81.77 85.55 87.75 90.69 92.58 94.30 95.52 96.47 67.5 73.40 83.11 86.78 88.90 91.63 93.25 94.75 95.92 96.80 70.0 73.95 84.32 87.83 89.85 92.53 93.88 95.20 96.34 97.10 72.5 74.42 85.46 88.81 90.67 93.24 94.42 95.60 96.72 97.38 75.0 75.38 86.67 89.95 91.67 93.96 95.03 96.06 97.12 97.67 77.5 76.68 87.81 90.95 92.56 94.58 95.57 96.51 97.50 97.94 80.0 78.62 88.82 91.90 93.41 95.15 96.09 96.96 97.86 98.19 82.5 80.81 89.96 92.93 94.27 95.69 96.58 97.40 98.21 98.46 85.0 83.23 91.14 94.02 95.20 96.33 97.12 97.86 98.55 98.73 87.5 85.85 92.39 94.99 95.93 96.92 97.61 98.29 98.84 98.97 90.0 88.36 93.80 96.02 96.69 97.56 98.09 98.68 99.11 99.19 92.5 91.00 95.40 97.11 97.49 98.27 98.59 99.06 99.36 99.42 95.0 93.49 96.99 98.19 98.28 99.02 99.08 99.39 99.59 99.64 97.5 96.16 98.70 98.90 99.05 99.27 99.50 99.71 99.81 99.85 
First-quartile storms; storm duration 6 to 12 hours

2.5 2.54 4.42 5.56 7.06 8.47 7.78 10.13 13.45 16.16 5.0 6.63 9.93 11.84 13.40 16.10 17.89 22.37 26.98 30.83 7.5 10.63 15.42 18.05 19.69 23.51 27.28 33.53 39.08 43.78 

10.0 14.63 21.03 24.21 26.03 30.90 35.80 43.23 49.32 54.65 12.5 18.70 26.44 29.98 32.02 37.70 43.15 50.95 57.24 62.93 15.0 22.70 31.59 35.30 37.63 43.83 49.54 57.20 63.36 69.10 17.5 26.62 36.32 40.03 42.66 49.06 54.71 61.91 67.84 73.35 20.0 30.60 40.61 44.24 47.18 53.68 59.40 65.91 71.73 76.89 22.5 34.52 44.31 47.98 51.29 57.58 63.32 69.15 74.87 79.54 25.0 38.14 47.67 51.53 55.12 61.22 66.87 72.15 77.74 81.77 27.5 41.67 50.93 54.95 58.67 64.79 70.32 75.01 80.37 83.69 30.0 45.04 53.88 58.11 61.94 68.12 73.55 77.79 82.62 85.27 32.5 48.03 56.86 61.17 65.01 71.18 76.44 80.34 84.46 86.49 35.0 50.60 60.00 64.23 67.82 73.97 79.05 82.59 86.11 87.62 37.5 52.71 62.81 67.09 70.42 76.34 81.20 84.60 87.56 88.67 40.0 54.13 64.66 69.22 72.48 77.85 82.49 85.96 88.65 89.52 42.5 55.01 66.28 71.14 74.11 78.97 83.32 86.89 89.56 90.32 45.0 55.25 67.30 72.61 75.40 79.70 83.72 87.37 90.23 90.97 47.5 55.40 67.99 73.70 76.38 80.26 83.96 87.70 90.71 91.57 50.0 55.50 68.57 74.48 77.14 80.66 84.03 87.71 90.95 91.97 52.5 55.69 69.47 75.34 78.04 81.43 84.33 87.91 91.21 92.35 55.0 56.37 70.35 76.02 78.85 82.00 84.56 87.97 91.37 92.67 57.5 57.55 71.47 76.85 79.63 82.61 84.96 88.22 91.59 93.05 60.0 59.12 72.47 77.57 80.34 83.11 85.34 88.46 91.84 93.39 62.5 60.28 73.63 78.31 80.91 83.64 85.84 88.85 92.12 93.81 65.0 61.11 74.76 79.05 81.34 83.93 86.37 89.25 92.43 94.25 67.5 61.21 75.71 79.78 81.79 84.45 87.02 89.83 92.85 94.70 70.0 61.60 76.33 80.37 82.38 85.05 87.63 90.40 93.29 95.11 72.5 61.90 76.90 81.04 82.92 85.87 88.41 91.08 93.80 95.52 75.0 62.30 77.15 81.54 83.52 86.70 89.30 91.85 94.41 95.93 77.5 62.60 77.42 82.20 84.24 87.69 90.25 92.67 95.04 96.36 80.0 63.00 77.90 83.01 85.11 88.74 91.25 93.55 95.66 96.78 82.5 63.40 79.06 84.09 86.05 89.84 92.38 94.44 96.27 97.21 85.0 63.70 80.80 85.47 87.43 91.02 93.48 95.35 96.85 97.64 87.5 67.70 83.37 87.46 89.20 92.42 94.58 96.23 97.39 98.07 90.0 71.65 86.52 89.74 91.19 93.90 95.72 97.11 97.92 98.50 92.5 80.02 90.16 92.25 93.36 95.42 96.91 97.93 98.44 98.93 95.0 88.16 93.81 94.80 95.54 96.97 98.07 98.77 98.95 99.36 97.5 95.93 97.45 97.39 97.69 98.51 99.24 99.57 99.45 99.79 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First-quartile storms; storm duration 12 to 24 hours 2.5 1.93 4.92 6.88 7.82 8.29 8.61 11.03 14.36 16.21 

5.0 6.08 11.08 13.65 14.90 16.81 18.60 22.63 28.10 31.14 7.5 10.60 17.23 20.39 21.94 25.13 28.03 33.26 40.44 44.55 

10.0 15.73 23.63 27.29 29.11 33.07 36.48 42.44 50.85 55.77 12.5 21.46 29.87 33.85 35.96 40.31 43.84 49.88 58.95 64.45 15.0 27.69 35.88 39.98 42.37 47.01 50.40 55.97 64.99 70.62 17.5 33.99 41.51 45.50 48.20 52.94 56.10 61.02 69.42 74.58 20.0 39.94 46.69 50.51 53.50 58.46 61.37 65.55 73.06 77.43 22.5 44.79 50.91 54.90 58.24 63.55 66.54 69.98 76.26 79.80 25.0 48.49 54.41 58.88 62.55 68.41 71.60 74.58 79.46 82.05 27.5 50.74 57.03 62.18 66.17 72.43 76.20 79.00 82.72 84.53 30.0 51.84 58.84 64.58 69.00 75.57 80.05 82.82 85.80 87.17 32.5 52.15 59.87 66.15 71.01 77.67 83.13 86.09 88.61 89.74 35.0 52.36 60.86 67.31 72.46 79.10 85.28 88.56 90.93 91.95 37.5 52.37 61.64 68.05 73.38 79.77 86.57 90.13 92.57 93.61 40.0 52.84 62.61 68.80 74.19 80.34 87.38 91.16 93.66 94.75 42.5 53.59 63.55 69.67 74.96 80.92 88.00 91.90 94.38 95.46 45.0 54.63 64.83 70.88 75.94 81.68 88.51 92.35 94.74 95.84 47.5 55.74 66.08 72.12 76.81 82.41 88.97 92.65 94.96 96.05 50.0 57.18 67.62 73.53 77.83 83.23 89.48 92.91 95.17 96.24 52.5 58.43 69.04 74.84 78.74 84.01 89.99 93.11 95.36 96.41 55.0 59.71 70.65 76.16 79.54 84.76 90.44 93.30 95.48 96.54 57.5 60.80 71.96 77.21 80.15 85.36 90.80 93.49 95.65 96.69 60.0 61.69 73.23 78.15 80.68 85.79 91.04 93.67 95.78 96.80 62.5 62.21 73.72 78.47 80.86 86.16 91.21 93.89 95.94 96.91 65.0 62.71 73.76 78.51 80.90 86.44 91.31 94.10 96.07 96.99 67.5 62.83 73.90 78.54 81.00 86.60 91.36 94.33 96.22 97.10 70.0 63.02 74.10 78.58 81.13 86.87 91.48 94.58 96.36 97.16 72.5 63.30 74.20 78.61 81.24 87.40 91.73 94.85 96.52 97.28 75.0 64.09 74.40 78.64 81.98 88.02 92.04 95.11 96.65 97.36 77.5 65.58 74.51 79.75 83.11 88.78 92.45 95.41 96.84 97.49 80.0 67.95 76.98 81.43 84.64 89.76 92.93 95.70 97.01 97.62 82.5 70.80 79.80 83.42 86.32 90.79 93.53 96.05 97.24 97.79 85.0 74.23 82.73 85.50 87.90 91.81 94.25 96.47 97.49 97.96 87.5 77.95 85.63 87.75 89.73 92.92 95.02 96.95 97.82 98.21 90.0 81.67 88.43 89.97 91.59 94.09 95.82 97.46 98.15 98.47 92.5 85.39 91.02 92.12 93.50 95.37 96.77 98.06 98.58 98.81 95.0 89.09 93.51 94.20 95.56 96.77 97.73 98.67 99.03 99.18 97.5 92.81 95.96 96.25 97.77 98.25 98.67 99.29 99.51 99.61 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First-quartile storms; storm duration 24 to 72 hours

2.5 3.03 4.69 5.60 6.88 9.29 12.07 15.64 20.29 21.82 5.0 6.69 11.26 12.98 14.87 18.39 22.49 26.87 32.62 35.38 7.5 10.35 17.15 19.83 22.24 26.67 31.68 36.69 43.13 47.00 

10.0 14.12 22.40 25.62 28.63 33.70 39.33 45.01 51.86 56.64 12.5 17.78 26.92 30.46 33.90 39.49 45.45 51.78 58.81 64.07 15.0 21.20 30.83 34.67 38.44 44.31 50.35 57.11 64.02 69.16 17.5 24.46 33.98 38.16 42.00 48.12 54.00 61.53 68.22 73.08 20.0 27.62 37.11 40.93 45.01 51.30 57.14 65.23 72.05 76.41 22.5 30.51 40.06 43.74 47.64 53.86 59.67 67.81 74.71 78.64 25.0 33.56 43.03 46.44 50.15 56.01 61.62 69.27 76.23 79.96 27.5 36.58 46.09 48.97 52.42 57.69 62.59 69.62 76.67 80.56 30.0 39.65 49.16 51.43 54.66 59.07 63.32 69.80 77.00 80.58 32.5 43.11 52.46 54.69 57.20 60.54 64.00 70.10 77.40 80.59 35.0 46.79 55.85 58.01 59.97 62.55 65.25 70.30 77.80 80.61 37.5 50.00 58.99 61.07 62.60 64.57 66.81 70.57 78.13 81.95 40.0 53.07 61.90 63.91 65.05 66.61 68.78 72.76 80.55 84.30 42.5 55.45 64.27 66.26 67.13 68.50 70.80 75.53 83.34 87.00 45.0 56.78 65.81 67.62 68.53 70.06 72.61 78.17 86.01 89.65 47.5 57.30 66.67 68.38 69.38 71.11 73.82 80.07 87.84 91.58 50.0 57.46 66.78 68.54 69.62 71.83 74.73 81.42 88.98 92.86 52.5 57.47 66.90 68.60 69.68 72.37 75.54 82.22 89.47 93.31 55.0 57.48 67.10 68.70 69.70 72.94 76.32 82.81 89.74 93.55 57.5 57.49 67.30 68.80 69.76 73.52 77.14 83.33 89.90 93.58 60.0 57.50 67.40 68.90 69.80 74.11 78.06 83.86 90.16 93.77 62.5 57.51 67.60 69.00 69.86 74.84 79.02 84.51 90.52 93.99 65.0 57.52 67.80 69.10 70.54 75.65 80.06 85.42 91.06 94.32 67.5 57.53 67.90 69.24 71.62 76.54 81.03 86.32 91.63 94.70 70.0 57.54 68.09 70.24 72.84 77.56 82.08 87.18 92.21 95.25 72.5 58.87 69.26 71.45 74.18 78.54 83.09 88.09 92.75 95.60 75.0 60.70 70.48 72.62 75.39 79.47 84.01 88.95 93.26 96.01 77.5 63.08 71.94 74.04 76.81 80.49 84.80 89.76 93.75 96.32 80.0 65.60 73.35 75.44 78.06 81.42 85.61 90.51 94.23 96.50 82.5 68.15 74.86 76.86 79.26 82.20 86.47 91.38 94.71 96.48 85.0 70.94 76.56 78.51 80.57 83.18 87.34 92.26 95.20 96.62 87.5 73.82 78.81 80.55 82.23 84.64 88.30 93.01 95.73 96.69 90.0 77.16 81.56 83.08 84.40 86.61 89.83 93.99 96.33 97.05 92.5 81.23 85.01 86.32 87.33 89.31 91.96 95.37 97.05 97.68 95.0 86.03 89.12 90.19 91.00 92.79 94.60 96.98 97.93 98.50 97.5 91.44 93.74 94.50 95.24 96.76 97.83 98.86 98.90 99.39 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First-quartile storms; storm duration 0 to 72 hours 2.5 1.82 4.68 5.87 7.09 8.51 8.72 11.15 14.79 17.06 

5.0 6.12 10.41 12.37 14.05 16.49 18.67 22.55 27.82 31.13 7.5 10.43 16.10 18.79 20.90 24.26 27.97 32.98 39.46 43.54 

10.0 14.90 21.99 25.27 27.76 31.81 36.29 42.10 49.36 53.90 12.5 19.40 27.76 31.44 34.17 38.78 43.51 49.68 57.26 61.91 15.0 24.00 33.37 37.26 40.10 45.17 49.94 55.93 63.40 67.84 17.5 28.48 38.60 42.50 45.35 50.70 55.41 61.14 68.11 72.14 20.0 32.81 43.39 47.18 49.99 55.60 60.42 65.87 72.22 75.77 22.5 36.68 47.35 50.98 53.83 59.83 64.97 70.07 75.75 78.75 25.0 40.20 50.71 54.19 57.10 63.51 69.08 74.01 78.93 81.44 27.5 43.19 53.47 56.79 59.74 66.48 72.51 77.59 81.82 83.94 30.0 45.88 55.80 58.90 61.86 68.93 75.31 80.56 84.34 86.21 32.5 48.09 57.80 60.69 63.55 70.85 77.46 82.91 86.43 88.22 35.0 50.01 60.03 62.70 65.36 72.58 79.20 84.85 88.18 90.01 37.5 51.68 62.07 64.60 67.18 74.19 80.55 86.29 89.49 91.36 40.0 53.21 63.94 66.41 69.00 75.76 81.73 87.38 90.56 92.43 42.5 54.40 65.56 68.05 70.79 77.21 82.80 88.30 91.43 93.26 45.0 55.57 67.01 69.57 72.60 78.61 83.80 89.06 92.11 93.83 47.5 56.67 67.98 70.67 74.00 79.75 84.62 89.63 92.67 94.23 50.0 57.74 68.89 71.68 75.23 80.69 85.36 90.15 93.19 94.63 52.5 58.64 69.60 72.56 76.25 81.46 86.00 90.60 93.58 94.95 55.0 59.55 70.30 73.42 77.11 82.08 86.55 90.96 93.89 95.20 57.5 60.32 70.90 74.19 77.82 82.68 87.10 91.36 94.17 95.46 60.0 60.98 71.50 74.97 78.44 83.21 87.64 91.75 94.44 95.70 62.5 61.49 72.05 75.67 78.95 83.73 88.19 92.12 94.68 95.95 65.0 61.96 72.69 76.41 79.51 84.33 88.80 92.53 94.96 96.19 67.5 62.26 73.27 77.10 80.02 84.99 89.44 92.95 95.24 96.44 70.0 62.67 73.96 77.84 80.63 85.67 90.09 93.37 95.55 96.69 72.5 63.20 74.67 78.63 81.37 86.40 90.74 93.79 95.86 96.93 75.0 64.03 75.46 79.44 82.16 87.17 91.39 94.23 96.19 97.15 77.5 65.36 76.39 80.33 83.08 87.99 92.03 94.67 96.52 97.38 80.0 67.26 77.47 81.31 84.13 88.87 92.65 95.10 96.84 97.59 82.5 69.53 78.66 82.37 85.18 89.70 93.31 95.54 97.15 97.79 85.0 72.36 80.23 83.58 86.33 90.58 94.07 96.05 97.49 98.01 87.5 75.69 82.35 85.30 87.94 91.65 94.83 96.57 97.85 98.25 90.0 79.41 84.91 87.43 89.80 92.92 95.66 97.15 98.22 98.54 92.5 83.65 88.11 90.12 92.03 94.44 96.67 97.83 98.64 98.87 95.0 88.42 91.88 93.27 94.64 96.25 97.78 98.56 99.10 99.25 97.5 93.48 95.96 96.82 97.53 98.33 98.93 99.31 99.56 99.65 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 0 to 6 hours

2.5 0.18 0.36 0.41 0.47 0.52 0.63 0.89 1.71 2.21 5.0 .74 1.28 1.67 2.02 2.56 3.01 3.74 4.96 5.66 7.5 1.23 2.29 3.00 3.60 4.52 5.32 6.53 8.19 9.08 

10.0 1.82 3.54 4.36 5.21 6.61 7.77 9.50 11.50 12.61 12.5 2.35 4.73 5.63 6.71 8.71 10.26 12.49 14.85 16.13 15.0 2.94 6.01 6.84 8.22 10.96 12.90 15.57 18.41 19.85 17.5 3.38 7.18 8.09 9.86 13.54 15.90 18.96 22.30 23.93 20.0 3.99 8.47 9.62 11.83 16.47 19.30 22.75 26.53 28.30 22.5 4.75 10.09 11.64 14.17 19.55 22.82 26.58 31.03 32.94 25.0 5.65 12.28 14.25 17.32 23.07 26.77 30.77 35.84 37.86 27.5 6.94 15.02 17.67 21.05 26.85 30.96 35.32 40.87 42.95 30.0 8.49 18.45 21.70 25.37 31.01 35.58 40.21 46.07 48.16 32.5 10.41 22.29 26.19 30.08 35.26 40.19 44.99 51.29 53.31 35.0 13.08 26.25 30.71 34.91 39.91 45.12 50.09 56.44 58.34 37.5 16.42 30.34 35.38 39.61 44.54 50.00 55.23 61.50 63.24 40.0 19.94 34.27 39.54 43.95 48.95 54.61 60.01 66.42 67.90 42.5 23.88 38.20 43.64 47.97 53.04 58.70 64.30 70.94 72.15 45.0 27.84 42.12 47.62 51.85 57.20 62.90 68.60 75.13 76.13 47.5 31.52 45.89 51.34 55.38 60.78 66.55 72.42 78.73 79.57 50.0 35.00 49.53 54.61 58.47 63.96 69.69 75.56 81.75 82.58 52.5 38.78 53.39 58.16 61.61 66.98 72.57 78.38 84.04 84.93 55.0 42.85 57.25 61.50 64.67 69.91 75.30 80.99 85.83 86.81 57.5 46.86 60.86 64.52 67.43 72.40 77.51 83.06 87.16 88.27 60.0 50.78 64.31 67.52 70.21 74.85 79.61 84.83 88.43 89.58 62.5 55.45 67.70 70.65 73.07 77.41 81.77 86.64 89.57 90.68 65.0 60.35 70.89 73.58 75.88 79.95 84.00 88.39 90.75 91.83 67.5 65.00 73.83 76.33 78.56 82.14 85.98 89.84 91.89 92.90 70.0 69.82 76.86 79.17 81.29 84.47 87.94 91.26 93.02 93.95 72.5 74.63 79.93 81.94 83.86 86.84 89.85 92.65 94.10 94.92 75.0 78.82 82.95 84.63 86.33 88.94 91.53 93.86 95.08 95.80 77.5 82.28 85.81 87.12 88.50 90.81 93.09 94.94 95.95 96.58 80.0 85.43 88.46 89.52 90.52 92.56 94.47 95.93 96.74 97.27 82.5 88.20 90.75 91.58 92.23 94.02 95.68 96.81 97.43 97.84 85.0 90.60 92.70 93.41 93.83 95.15 96.69 97.49 97.95 98.30 87.5 92.39 94.24 94.85 95.17 96.18 97.54 98.08 98.43 98.70 90.0 94.02 95.56 96.14 96.44 97.20 98.23 98.61 98.85 99.05 92.5 95.46 96.71 97.23 97.59 98.18 98.82 99.06 99.21 99.34 95.0 96.90 97.88 98.35 98.79 99.09 99.31 99.44 99.53 99.60 97.5 98.33 99.03 99.42 99.53 99.63 99.74 99.78 99.84 99.86 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 6 to 12 hours 2.5 0.26 0.52 0.64 0.73 1.38 1.88 3.69 4.76 6.68 

5.0 .71 1.53 2.03 2.49 3.87 4.89 6.87 12.39 15.13 7.5 1.23 2.57 3.39 4.16 6.25 7.80 10.02 19.39 22.57 

10.0 1.80 3.73 4.94 5.93 8.64 10.68 13.24 24.92 28.02 12.5 2.48 4.96 6.51 7.72 10.92 13.43 16.38 28.88 31.48 15.0 3.25 6.21 8.14 9.53 13.19 16.15 19.39 31.62 33.81 17.5 4.12 7.56 9.79 11.40 15.27 18.78 22.29 33.23 35.07 20.0 5.10 8.93 11.53 13.39 17.45 21.49 25.13 34.37 36.53 22.5 6.27 10.33 13.19 15.34 19.73 24.19 27.80 35.90 39.06 25.0 7.57 11.82 15.11 17.44 22.18 27.14 30.53 37.88 42.63 27.5 9.12 13.39 17.06 19.48 24.65 30.07 33.25 40.29 46.53 30.0 11.16 15.40 19.39 21.59 27.39 33.10 36.08 43.40 51.19 32.5 13.37 17.92 22.16 24.35 30.81 36.40 39.34 46.88 55.39 35.0 16.02 21.06 25.50 27.76 34.40 39.95 42.91 50.73 59.08 37.5 18.77 24.74 29.15 31.60 38.70 43.78 46.86 55.10 62.37 40.0 21.79 29.24 33.34 36.39 43.87 48.32 51.56 59.94 66.09 42.5 24.22 33.86 37.68 41.60 49.11 52.98 56.31 64.48 69.22 45.0 26.99 38.65 42.09 46.56 53.91 57.54 60.79 68.95 72.52 47.5 29.42 43.08 46.40 51.31 58.53 61.97 65.13 72.84 75.55 50.0 32.80 47.45 50.66 55.74 62.39 65.94 69.14 76.07 78.24 52.5 36.70 51.35 54.72 59.47 65.42 69.21 72.38 78.60 80.33 55.0 41.99 55.19 58.70 63.05 68.45 72.49 75.77 81.18 82.55 57.5 47.48 58.95 62.59 66.38 71.46 75.68 79.06 83.43 84.58 60.0 53.48 63.00 66.32 69.42 74.38 78.68 82.07 85.70 86.73 62.5 58.75 67.07 70.10 72.60 77.40 81.74 84.75 87.92 88.93 65.0 62.98 71.01 73.61 75.70 80.32 84.47 87.19 90.05 91.01 67.5 65.86 74.59 76.77 78.41 82.92 86.78 89.02 91.64 92.69 70.0 68.13 77.52 79.39 80.79 85.15 88.64 90.44 92.97 94.09 72.5 70.01 79.93 81.67 82.91 87.17 90.23 91.65 94.00 95.18 75.0 71.71 81.80 83.43 84.54 88.78 91.46 92.79 94.85 96.00 77.5 74.12 83.47 85.05 86.00 90.29 92.71 93.94 95.55 96.64 80.0 77.06 84.99 86.54 87.43 91.62 93.82 95.05 96.29 97.22 82.5 80.25 86.79 88.19 88.99 92.86 94.90 96.09 97.03 97.77 85.0 83.46 88.57 89.84 90.59 93.95 95.89 97.02 97.74 98.28 87.5 86.73 90.47 91.55 92.26 95.12 96.80 97.76 98.35 98.73 90.0 89.65 92.44 93.31 93.95 96.22 97.61 98.35 98.86 99.14 92.5 92.47 94.55 95.15 95.68 97.34 98.37 98.88 99.26 99.46 95.0 95.28 96.68 97.02 97.42 98.50 99.05 99.38 99.57 99.73 97.5 98.10 98.91 98.96 99.19 99.73 99.79 99.85 99.90 99.95 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 12 to 24 hours

2.5 1.35 1.72 1.95 2.18 3.42 4.87 6.33 7.51 8.92 5.0 2.76 3.77 4.08 5.14 7.10 9.98 13.61 17.04 19.31 7.5 4.23 5.84 6.75 8.03 10.64 15.07 20.58 25.66 28.60 

10.0 5.58 7.93 9.42 10.99 14.20 19.96 26.66 32.48 35.93 12.5 6.67 9.87 11.95 13.82 17.63 24.40 31.65 37.36 41.03 15.0 7.67 11.76 14.32 16.57 20.94 28.33 35.59 41.27 44.95 17.5 8.28 13.63 16.61 19.33 24.14 31.73 38.58 44.22 47.74 20.0 8.69 15.50 18.83 22.14 27.41 34.68 40.99 46.59 49.93 22.5 9.33 17.33 20.96 24.91 30.62 37.48 43.37 48.92 51.88 25.0 10.22 19.18 23.05 27.71 33.82 40.33 45.87 51.43 54.16 27.5 11.31 21.19 25.30 30.57 37.03 43.32 48.70 54.30 56.82 30.0 12.98 23.36 27.65 33.41 40.28 46.33 51.69 57.27 59.84 32.5 15.05 25.71 30.21 36.23 43.45 49.40 54.78 60.51 63.31 35.0 17.50 28.33 32.92 39.15 46.70 52.50 57.87 63.88 67.24 37.5 20.55 31.46 36.03 42.26 49.97 55.64 60.99 67.30 71.15 40.0 24.17 34.91 39.42 45.30 53.15 58.77 64.10 70.42 74.38 42.5 28.53 39.04 43.41 48.73 56.43 61.73 67.14 73.44 77.26 45.0 33.34 43.47 47.70 52.43 59.83 64.78 70.15 76.20 79.76 47.5 38.29 47.89 51.97 56.01 63.00 67.83 73.17 78.88 81.88 50.0 43.26 52.28 56.17 59.53 66.22 70.82 76.02 81.42 83.89 52.5 47.82 56.36 60.05 63.07 69.27 73.70 78.68 83.91 86.18 55.0 51.54 59.67 63.18 65.99 71.94 76.58 81.24 86.25 88.44 57.5 54.68 62.55 65.77 68.46 74.24 79.08 83.53 88.49 90.46 60.0 57.31 65.17 68.15 70.66 76.34 81.48 85.54 90.48 92.26 62.5 59.27 67.40 70.14 72.56 77.95 83.37 87.34 92.11 93.68 65.0 61.07 69.45 72.02 74.35 79.52 84.96 88.92 93.29 94.70 67.5 62.68 71.25 73.67 75.99 80.86 86.25 90.16 94.20 95.37 70.0 64.25 72.99 75.27 77.58 82.10 87.43 91.18 94.84 95.89 72.5 65.94 74.71 76.81 79.12 83.17 88.32 92.09 95.30 96.29 75.0 68.15 76.46 78.40 80.72 84.34 89.35 92.93 95.76 96.71 77.5 70.56 78.30 80.00 82.20 85.41 90.39 93.66 96.24 97.10 80.0 73.50 80.41 81.89 83.90 86.71 91.55 94.50 96.71 97.50 82.5 76.74 82.59 83.88 85.65 88.15 92.74 95.35 97.20 97.90 85.0 80.17 84.83 85.94 87.59 89.93 93.97 96.15 97.68 98.27 87.5 83.56 87.40 88.27 89.74 91.90 95.21 96.97 98.16 98.62 90.0 87.04 90.09 90.74 92.04 94.02 96.46 97.79 98.63 98.97 92.5 90.42 92.74 93.24 94.31 95.96 97.57 98.49 99.05 99.27 95.0 93.76 95.41 95.76 96.58 97.72 98.57 99.11 99.43 99.56 97.5 97.11 98.15 98.41 98.79 99.27 99.54 99.70 99.79 99.84 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 24 to 72 hours 2.5 0.91 2.04 2.47 3.19 4.63 7.06 9.60 12.54 15.23 

5.0 1.76 4.10 5.27 7.01 10.03 15.85 23.14 27.61 31.05 7.5 2.43 5.86 7.67 10.28 14.80 23.25 35.71 41.48 45.35 

10.0 2.91 7.08 9.43 12.88 18.52 29.29 46.52 53.53 57.48 12.5 3.26 7.83 10.41 14.60 21.00 33.72 53.70 62.35 66.72 15.0 3.41 8.30 11.31 16.10 22.82 36.38 55.38 67.20 72.62 17.5 3.56 8.63 12.13 17.31 24.16 37.15 56.56 68.67 73.23 20.0 3.92 9.28 13.42 18.90 25.49 37.93 57.75 69.65 73.85 22.5 4.61 10.32 15.14 20.89 27.16 38.52 58.03 69.92 74.46 25.0 5.56 11.76 17.46 23.39 29.53 39.56 58.31 70.19 74.59 27.5 6.87 13.83 20.01 25.95 32.22 41.30 58.58 70.46 74.71 30.0 8.52 16.10 22.83 28.80 35.21 43.62 58.86 70.72 74.84 32.5 10.55 18.47 25.62 31.80 38.51 46.36 59.14 71.00 74.96 35.0 12.97 21.47 28.71 34.88 41.94 49.55 59.42 71.26 75.09 37.5 16.44 25.24 32.05 38.07 45.22 52.59 60.20 71.53 75.22 40.0 20.65 29.44 35.61 41.51 48.60 55.66 62.71 71.80 75.34 42.5 25.57 34.81 39.79 45.06 51.86 58.78 65.76 72.60 76.00 45.0 30.79 40.79 44.50 48.79 54.96 61.72 68.71 74.78 78.41 47.5 36.28 46.56 49.25 52.75 58.05 64.61 71.65 77.43 81.23 50.0 40.97 51.58 53.66 56.67 61.44 67.72 74.56 79.93 83.65 52.5 45.24 55.81 57.60 60.48 64.86 70.79 77.37 82.11 85.73 55.0 48.85 59.07 60.94 64.22 68.45 74.07 80.38 84.53 87.82 57.5 51.93 61.67 63.52 67.48 72.27 77.50 83.45 87.07 89.83 60.0 54.36 63.94 65.83 70.38 76.12 81.03 86.45 89.62 91.76 62.5 56.77 66.36 68.33 73.08 79.46 84.21 89.14 91.94 93.58 65.0 58.68 69.11 71.19 75.69 82.56 87.09 91.42 93.96 95.14 67.5 60.53 71.72 73.88 78.02 85.17 89.38 93.02 95.33 96.21 70.0 62.27 74.16 76.59 80.42 87.11 91.03 94.09 96.20 96.91 72.5 63.76 76.11 78.67 82.15 88.44 92.00 94.65 96.63 97.21 75.0 64.96 77.44 80.03 83.46 89.31 92.65 94.93 96.84 97.33 77.5 66.22 78.10 80.88 84.35 89.75 93.06 95.10 96.98 97.40 80.0 66.92 78.26 80.94 84.50 90.05 93.18 95.27 97.16 97.52 82.5 67.48 78.42 81.00 84.64 90.40 93.36 95.50 97.37 97.70 85.0 68.75 78.59 81.20 84.80 90.88 93.59 95.78 97.63 97.98 87.5 70.59 78.75 82.36 84.94 91.82 94.08 96.21 97.94 98.29 90.0 73.48 80.79 84.07 86.27 93.22 94.74 96.74 98.29 98.61 92.5 78.33 84.77 87.41 89.19 94.87 95.72 97.36 98.68 98.98 95.0 84.85 89.89 91.64 93.08 96.62 96.78 97.99 99.11 99.39 97.5 92.14 95.41 96.14 97.16 98.54 98.61 98.68 99.54 99.80 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 0 to 72 hours

2.5 0.69 1.32 1.81 2.25 2.90 3.77 6.16 8.81 9.95 5.0 1.46 3.02 3.83 4.74 6.24 9.44 13.76 19.05 21.98 7.5 2.23 4.71 5.81 7.16 9.54 14.70 20.65 28.23 32.79 

10.0 2.89 6.31 7.70 9.51 12.70 19.09 26.28 35.37 41.40 12.5 3.46 7.69 9.43 11.68 15.56 22.55 30.60 40.29 47.38 15.0 4.02 9.03 11.12 13.82 18.25 25.46 33.83 43.63 51.23 17.5 4.44 10.15 12.68 15.77 20.69 27.36 35.95 45.48 53.18 20.0 4.95 11.28 14.31 17.81 22.97 29.13 37.77 46.63 54.01 22.5 5.68 12.58 16.15 20.00 25.33 31.25 39.89 48.07 54.77 25.0 6.70 14.32 18.38 22.57 28.12 33.89 42.33 49.92 55.93 27.5 7.97 16.22 20.81 25.34 31.18 36.86 45.23 52.30 57.61 30.0 9.67 18.51 23.49 28.41 34.57 40.42 48.54 55.03 59.74 32.5 11.80 20.99 26.33 31.53 38.23 44.14 52.01 58.16 62.45 35.0 14.38 23.84 29.31 34.68 42.01 47.98 55.60 61.38 65.43 37.5 17.68 27.20 32.67 37.97 45.75 51.70 59.19 64.74 68.55 40.0 21.73 31.25 36.42 41.52 49.50 55.36 62.71 68.14 71.74 42.5 26.53 36.03 40.79 45.42 53.21 58.85 66.10 71.51 74.88 45.0 31.67 41.36 45.49 49.57 56.84 62.27 69.39 74.78 77.84 47.5 37.05 46.55 50.24 53.85 60.34 65.51 72.29 77.74 80.52 50.0 42.18 51.36 54.64 57.94 63.71 68.74 75.13 80.46 82.95 52.5 46.81 55.47 58.55 61.61 66.77 71.85 77.81 82.89 85.17 55.0 50.80 58.90 61.82 64.85 69.72 74.94 80.43 85.25 87.34 57.5 54.37 61.79 64.80 67.86 72.62 77.97 82.90 87.35 89.32 60.0 57.21 64.47 67.61 70.66 75.47 81.03 85.47 89.43 91.21 62.5 59.64 67.01 70.26 73.19 78.07 83.66 87.66 91.27 92.90 65.0 61.85 69.55 72.93 75.68 80.61 85.93 89.51 92.80 94.33 67.5 63.90 71.82 75.51 77.98 82.94 87.86 91.04 93.93 95.31 70.0 65.83 73.96 77.81 80.04 84.91 89.36 92.26 94.83 96.05 72.5 67.83 75.94 79.78 81.79 86.55 90.42 93.10 95.46 96.51 75.0 69.79 77.71 81.50 83.40 88.04 91.43 93.88 95.98 96.86 77.5 71.75 79.37 82.99 84.80 89.32 92.38 94.60 96.46 97.15 80.0 73.34 81.10 84.31 86.06 90.40 93.27 95.27 96.93 97.48 82.5 74.95 82.89 85.68 87.29 91.48 94.20 95.96 97.38 97.82 85.0 76.83 84.71 87.23 88.67 92.55 95.10 96.64 97.82 98.17 87.5 79.09 86.77 89.04 90.27 93.68 95.98 97.29 98.23 98.51 90.0 81.81 89.05 91.04 92.03 94.87 96.88 97.93 98.64 98.86 92.5 85.64 91.52 93.20 93.96 96.16 97.78 98.56 99.03 99.21 95.0 90.20 94.09 95.40 95.96 97.49 98.67 99.18 99.42 99.58 97.5 95.14 96.84 97.61 97.98 98.85 99.60 99.80 99.82 99.97 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 0 to 6 hours 2.5 0.32 0.38 0.54 1.16 1.86 2.66 4.06 4.57 5.47 

5.0 .72 1.42 1.78 2.54 4.33 5.64 7.40 8.51 9.52 7.5 1.13 2.33 2.88 3.87 6.79 8.45 10.50 12.13 13.25 

10.0 1.55 3.20 3.91 5.17 9.08 11.05 13.46 15.61 16.90 12.5 1.97 4.04 4.92 6.45 11.17 13.35 15.99 18.60 20.02 15.0 2.42 4.89 5.93 7.74 12.92 15.45 18.20 21.30 22.84 17.5 2.88 5.73 6.91 8.97 14.29 17.05 19.77 23.45 25.16 20.0 3.47 6.60 7.86 10.15 15.10 18.26 21.10 25.43 27.29 22.5 4.03 7.66 9.06 11.40 15.88 19.40 22.12 26.86 28.89 25.0 4.65 8.69 10.18 12.71 16.70 20.58 23.10 28.17 30.38 27.5 5.18 9.74 11.30 14.01 17.65 21.61 24.25 29.33 31.60 30.0 5.56 10.91 12.53 15.29 18.63 22.82 25.51 30.46 33.30 32.5 5.85 12.17 13.85 16.56 20.18 24.48 26.96 31.52 34.91 35.0 6.12 13.32 15.11 17.78 21.64 26.18 28.46 32.81 36.83 37.5 6.38 14.58 16.57 19.03 22.94 28.05 30.40 34.25 38.97 40.0 6.00 16.27 18.01 20.36 24.72 30.26 32.11 35.64 41.46 42.5 6.35 18.44 19.56 21.88 27.02 32.71 34.27 37.43 44.04 45.0 8.09 20.91 21.78 24.01 29.41 35.39 37.01 40.00 47.42 47.5 11.07 24.03 24.56 26.78 32.37 38.51 40.49 43.37 51.05 50.0 15.14 27.51 27.55 29.99 36.05 41.86 44.27 47.90 55.80 52.5 19.63 31.14 31.22 33.73 39.95 45.41 48.77 53.71 61.49 55.0 22.96 34.69 35.51 38.21 44.05 49.32 53.49 59.58 67.02 57.5 24.82 38.51 39.67 42.64 48.40 53.21 58.07 65.07 71.85 60.0 25.01 42.09 43.85 47.10 52.95 57.14 62.51 70.11 76.23 62.5 25.21 45.90 48.31 51.59 57.36 61.00 66.68 74.12 79.38 65.0 27.00 49.68 52.70 56.07 61.67 64.83 70.50 76.95 81.18 67.5 29.44 53.69 57.00 60.33 65.76 68.41 74.04 79.57 82.60 70.0 34.95 57.74 61.42 64.54 69.70 71.97 77.31 81.91 83.95 72.5 42.90 62.43 65.88 68.62 73.39 75.42 80.24 83.99 85.52 75.0 51.31 67.25 70.56 72.75 76.93 78.78 82.99 86.00 87.19 77.5 59.44 72.02 75.00 76.55 80.03 81.80 85.56 88.03 88.95 80.0 66.02 76.47 78.82 79.87 83.00 84.73 87.86 89.81 90.68 82.5 72.12 80.76 82.41 83.08 85.88 87.48 90.10 91.63 92.50 85.0 77.09 84.20 85.49 85.98 88.39 89.83 92.28 93.41 94.11 87.5 81.75 87.30 88.14 88.65 90.78 92.01 94.21 94.98 95.51 90.0 85.74 90.20 90.73 91.28 93.11 94.13 95.89 96.38 96.80 92.5 89.74 93.06 93.46 93.95 95.26 96.05 97.37 97.67 97.93 95.0 93.53 95.82 96.14 96.53 97.28 97.87 98.56 98.73 98.85 97.5 97.32 98.69 98.86 99.12 99.36 99.44 99.51 99.59 99.63 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 6 to 12 hours

2.5 0.40 0.78 0.79 0.91 1.25 2.09 2.78 3.10 4.36 5.0 .89 1.87 2.09 2.39 3.07 4.11 5.14 6.80 7.86 7.5 1.33 2.84 3.27 3.81 4.85 6.05 7.34 10.11 11.08 

10.0 1.71 3.76 4.40 5.18 6.58 8.02 9.64 13.18 14.48 12.5 2.06 4.63 5.49 6.51 8.19 9.88 11.72 15.40 17.38 15.0 2.36 5.35 6.49 7.76 9.80 11.67 13.80 17.61 20.20 17.5 2.63 5.95 7.35 8.85 11.24 13.28 15.57 19.66 22.73 20.0 2.91 6.52 8.20 9.77 12.49 14.87 17.73 22.05 25.63 22.5 3.19 7.04 9.05 10.63 13.61 16.25 19.67 24.25 28.05 25.0 3.51 7.50 9.85 11.38 14.62 17.55 22.08 27.33 31.23 27.5 3.81 7.89 10.51 12.02 15.46 18.74 24.26 29.90 34.17 30.0 4.12 8.21 11.05 12.51 16.15 19.74 26.48 32.13 36.77 32.5 4.40 8.58 11.54 13.07 16.82 20.56 27.88 33.83 38.53 35.0 4.60 8.84 11.75 13.41 17.29 21.24 28.77 34.92 39.75 37.5 4.73 9.13 11.82 13.73 17.78 21.77 28.82 35.11 39.99 40.0 5.05 9.75 11.99 14.02 18.17 22.19 28.87 35.30 40.23 42.5 5.34 10.55 12.37 14.60 18.82 22.83 28.92 35.49 40.50 45.0 5.77 11.55 13.22 15.52 19.83 23.63 28.97 35.68 40.72 47.5 6.47 13.04 14.81 17.30 21.68 25.22 29.80 36.00 40.96 50.0 7.40 14.79 16.89 19.51 23.96 27.58 31.45 38.26 42.00 52.5 8.52 16.82 19.63 22.48 27.03 30.70 34.81 41.69 44.84 55.0 10.04 19.33 22.73 25.81 30.61 34.67 38.99 45.86 49.14 57.5 11.69 22.08 25.81 29.24 34.50 39.27 43.65 50.42 53.97 60.0 13.66 25.10 28.94 32.52 38.51 43.97 48.43 55.17 59.01 62.5 15.69 28.62 32.58 36.37 42.91 48.87 53.36 60.11 64.27 65.0 17.41 32.33 36.15 40.53 47.52 53.85 58.47 65.04 69.28 67.5 19.81 36.52 40.32 45.23 52.39 58.53 63.44 69.97 73.98 70.0 23.43 41.50 45.28 50.61 57.76 63.39 68.35 74.89 78.37 72.5 28.15 47.20 51.04 56.68 63.35 68.41 73.21 79.48 82.24 75.0 34.31 53.40 57.16 62.81 69.09 73.44 77.91 83.42 85.50 77.5 42.55 60.31 63.95 68.82 74.69 78.31 82.12 86.75 88.27 80.0 51.41 67.32 70.72 74.70 80.01 83.03 85.91 89.44 90.58 82.5 60.09 73.90 77.05 80.09 84.61 87.09 89.24 91.68 92.54 85.0 68.37 79.69 82.52 84.68 88.47 90.41 91.94 93.50 94.20 87.5 76.15 84.85 87.18 88.60 91.57 93.04 94.09 95.10 95.61 90.0 82.65 89.08 90.86 91.89 94.03 95.09 95.83 96.48 96.84 92.5 88.13 92.48 93.79 94.47 95.95 96.68 97.25 97.67 97.90 95.0 92.89 95.41 96.23 96.63 97.59 98.04 98.41 98.64 98.78 97.5 97.19 98.15 98.46 98.59 99.09 99.28 99.43 99.51 99.58 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 12 to 24 hours 2.5 0.34 0.79 1.04 1.23 1.39 1.82 2.16 3.19 4.45 

5.0 .87 1.93 2.35 2.70 3.21 4.05 4.97 6.31 7.61 7.5 1.42 3.10 3.65 4.18 5.03 6.27 7.66 9.37 10.85 

10.0 1.84 4.11 4.82 5.58 6.83 8.49 10.26 12.32 14.08 12.5 2.18 5.02 5.94 6.93 8.62 10.66 12.75 15.24 17.28 15.0 2.51 5.85 7.03 8.25 10.36 12.82 15.07 18.15 20.29 17.5 2.83 6.55 8.06 9.48 12.03 14.86 17.26 21.00 23.35 20.0 3.10 7.14 8.97 10.57 13.58 16.72 19.39 23.82 26.55 22.5 3.42 7.76 9.89 11.68 15.06 18.45 21.48 26.49 30.00 25.0 3.77 8.33 10.76 12.77 16.58 20.23 23.62 29.20 33.61 27.5 4.11 8.81 11.57 13.76 18.07 21.90 25.86 31.98 37.33 30.0 4.30 9.21 12.30 14.69 19.50 23.59 28.19 34.83 41.07 32.5 4.56 9.65 12.94 15.59 20.84 25.27 30.53 37.75 44.56 35.0 4.76 10.13 13.54 16.42 22.15 26.99 32.59 40.58 47.77 37.5 4.84 10.54 14.03 17.09 23.14 28.42 34.52 42.99 50.80 40.0 4.93 11.04 14.55 17.64 24.10 29.93 36.37 45.32 53.73 42.5 5.34 11.81 15.22 18.23 24.87 31.01 37.80 47.30 55.68 45.0 6.02 12.76 16.14 19.06 25.97 32.27 39.21 48.85 57.06 47.5 7.35 14.17 17.57 20.47 27.62 33.95 41.19 50.42 57.92 50.0 9.19 16.11 19.50 22.48 30.12 36.49 43.78 52.38 58.54 52.5 11.80 18.94 22.31 25.64 33.53 39.68 47.16 54.96 59.84 55.0 15.05 22.39 26.21 30.06 38.30 44.23 51.78 58.57 62.74 57.5 18.77 26.70 31.10 35.44 43.76 49.54 57.15 63.09 66.68 60.0 22.60 31.33 36.40 41.15 49.54 55.13 62.72 68.28 71.46 62.5 26.52 36.45 42.25 47.37 55.48 60.83 68.10 73.60 76.75 65.0 30.10 41.25 47.62 53.12 61.01 66.30 72.91 78.18 81.42 67.5 33.24 46.10 52.31 58.03 65.70 71.11 76.91 81.91 85.12 70.0 36.39 50.55 56.50 62.37 69.73 75.28 80.13 84.72 87.96 72.5 39.84 55.04 60.55 66.28 73.28 78.87 82.77 86.79 90.09 75.0 44.32 59.47 64.37 69.72 76.37 81.71 84.98 88.46 91.54 77.5 49.80 64.24 68.57 73.16 79.29 84.22 86.91 89.97 92.67 80.0 56.39 69.05 72.86 76.68 82.24 86.53 88.78 91.37 93.72 82.5 63.19 73.80 77.05 80.06 85.10 88.69 90.67 92.96 94.86 85.0 69.74 78.28 80.97 83.38 87.75 90.72 92.58 94.57 96.03 87.5 75.62 82.54 84.67 86.57 90.20 92.72 94.39 95.99 97.11 90.0 80.91 86.42 88.02 89.60 92.46 94.51 96.01 97.21 98.07 92.5 85.61 90.03 91.31 92.58 94.59 96.13 97.36 98.24 98.84 95.0 90.17 93.62 94.60 95.54 96.77 97.65 98.48 99.02 99.40 97.5 94.84 97.20 97.90 98.50 98.95 99.09 99.44 99.66 99.80 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 24 to 72 hours

2.5 1.04 1.74 1.79 1.86 2.46 3.78 4.85 6.97 8.34 5.0 1.91 3.28 3.99 4.58 5.74 7.82 9.70 13.81 17.58 7.5 2.71 4.69 6.07 7.07 8.71 11.76 14.28 19.99 25.81 

10.0 3.48 6.03 7.90 9.14 11.27 15.48 18.67 26.06 33.32 12.5 4.14 7.23 9.36 10.74 13.32 18.68 22.56 31.54 39.47 15.0 4.71 8.30 10.50 11.96 14.94 21.29 25.83 35.96 44.21 17.5 5.19 9.13 11.32 12.84 16.27 23.32 28.41 39.42 48.12 20.0 5.61 9.83 12.00 13.64 17.52 24.82 30.42 42.33 51.41 22.5 5.96 10.37 12.51 14.31 18.62 25.77 31.49 43.25 52.56 25.0 6.34 10.83 13.06 14.97 19.77 26.65 32.23 43.51 52.63 27.5 6.73 11.21 13.63 15.66 20.91 27.45 32.79 43.76 52.70 30.0 7.12 11.66 14.27 16.41 22.05 28.29 33.45 44.00 52.76 32.5 7.52 12.12 14.74 16.98 23.04 29.04 34.26 44.28 52.83 35.0 7.89 12.62 15.40 17.81 24.09 30.04 35.60 44.54 52.90 37.5 8.24 13.08 15.89 18.47 24.90 30.95 36.84 44.80 52.97 40.0 8.62 13.57 16.47 19.20 25.67 31.74 37.95 45.05 53.04 42.5 8.90 14.24 17.20 20.04 26.47 32.47 38.86 45.31 53.10 45.0 9.32 15.46 18.62 21.61 27.70 33.71 39.92 46.00 53.17 47.5 9.96 17.65 20.81 23.76 29.57 35.49 41.36 47.73 54.00 50.0 11.13 20.93 24.21 27.02 32.44 38.22 44.07 50.79 56.04 52.5 12.56 25.06 28.42 31.02 36.59 42.34 48.04 54.99 59.95 55.0 14.40 29.06 32.78 35.41 41.15 47.25 52.96 60.36 65.04 57.5 16.46 32.78 36.79 39.62 45.73 52.35 58.31 65.99 70.54 60.0 18.94 35.75 40.22 43.41 50.08 57.16 63.44 71.12 75.60 62.5 21.04 38.01 42.99 46.72 54.04 61.55 67.74 75.48 79.69 65.0 23.31 39.67 45.24 49.58 56.99 64.99 71.26 78.98 82.70 67.5 25.38 42.09 47.80 52.37 59.85 68.02 74.36 81.67 84.95 70.0 27.36 44.51 50.57 55.15 62.71 70.65 76.91 83.82 86.56 72.5 29.07 47.16 53.56 57.97 65.64 73.30 79.25 85.64 87.90 75.0 31.33 50.05 56.71 60.79 68.58 75.73 81.35 87.15 89.21 77.5 33.88 53.47 60.17 64.09 71.77 78.21 83.44 88.49 90.52 80.0 37.45 56.82 63.68 67.55 75.04 80.54 85.33 89.79 91.70 82.5 42.39 61.02 67.59 71.36 78.39 82.99 87.38 91.10 92.89 85.0 48.76 65.80 71.81 75.52 81.72 85.38 89.52 92.62 94.18 87.5 56.23 71.18 76.37 79.93 85.07 87.87 91.76 94.25 95.47 90.0 64.67 76.93 81.16 84.27 88.43 90.39 93.73 95.78 96.66 92.5 73.59 83.08 86.15 88.68 91.80 93.03 95.60 97.09 97.69 95.0 82.25 89.24 91.19 92.99 95.16 95.69 97.32 98.25 98.60 97.5 90.85 95.55 96.31 97.27 98.52 98.70 98.89 99.25 99.44 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 0 to 72 hours 2.5 0.63 1.21 1.52 1.78 1.89 2.46 3.44 5.02 6.08 

5.0 1.43 2.56 3.10 3.59 4.55 5.82 7.63 10.15 11.95 7.5 2.18 3.85 4.62 5.33 6.99 8.88 11.60 14.94 17.36 

10.0 2.95 5.12 6.13 7.05 9.14 11.65 15.22 19.35 22.43 12.5 3.55 6.23 7.53 8.63 10.96 13.97 18.20 23.07 26.58 15.0 4.00 7.20 8.74 10.00 12.53 15.94 20.70 26.16 29.90 17.5 4.37 8.01 9.74 11.12 13.85 17.55 22.75 28.43 32.37 20.0 4.67 8.72 10.58 12.12 15.15 19.12 24.49 30.41 34.48 22.5 4.86 9.29 11.26 12.96 16.33 20.48 25.93 31.84 35.74 25.0 5.16 9.85 11.83 13.71 17.55 21.92 27.49 33.27 37.02 27.5 5.58 10.39 12.42 14.49 18.78 23.34 29.00 34.62 38.23 30.0 5.89 10.89 12.93 15.27 19.96 24.74 30.47 36.03 39.55 32.5 6.22 11.34 13.42 15.94 21.04 25.98 31.85 37.26 40.72 35.0 6.47 11.76 13.93 16.66 22.14 27.32 33.28 38.67 42.26 37.5 6.63 12.13 14.40 17.28 22.99 28.34 34.47 39.91 43.74 40.0 6.73 12.51 14.91 17.85 23.70 29.23 35.57 41.13 45.22 42.5 6.99 13.05 15.60 18.53 24.40 30.10 36.53 42.17 46.46 45.0 7.48 14.04 16.71 19.72 25.48 31.34 37.72 43.59 48.00 47.5 8.49 15.77 18.63 21.61 27.28 33.09 39.50 45.53 49.95 50.0 9.88 18.19 21.34 24.43 30.04 35.86 42.19 48.37 52.72 52.5 11.75 21.36 24.66 27.94 33.76 39.68 45.90 52.21 56.49 55.0 13.94 24.82 28.53 32.00 38.26 44.31 50.51 57.16 61.29 57.5 16.27 28.47 32.69 36.43 43.02 49.32 55.60 62.45 66.54 60.0 18.77 31.98 36.68 40.78 47.65 54.33 60.59 67.62 71.51 62.5 21.27 35.54 40.53 44.86 52.11 59.15 65.33 72.35 75.95 65.0 23.77 38.86 44.26 48.81 56.18 63.45 69.51 76.32 79.61 67.5 26.47 42.63 48.03 52.78 60.05 67.38 73.33 79.59 82.61 70.0 29.45 46.50 51.79 56.60 63.83 70.94 76.69 82.31 85.00 72.5 32.55 50.68 55.67 60.48 67.54 74.28 79.79 84.67 87.07 75.0 36.54 55.04 59.68 64.46 71.22 77.35 82.47 86.64 88.83 77.5 41.40 59.82 63.96 68.49 74.93 80.36 84.97 88.50 90.44 80.0 46.85 64.54 68.20 72.49 78.51 83.23 87.23 90.14 91.82 82.5 53.06 69.43 72.56 76.45 81.92 86.02 89.38 91.79 93.19 85.0 59.93 74.24 76.88 80.27 85.14 88.65 91.42 93.38 94.54 87.5 66.90 78.92 81.14 83.97 88.10 91.12 93.41 94.96 95.85 90.0 73.81 83.40 85.26 87.59 90.83 93.29 95.15 96.34 96.99 92.5 80.85 87.78 89.38 91.12 93.47 95.27 96.68 97.56 97.99 95.0 87.62 92.00 93.39 94.59 96.12 97.13 98.03 98.58 98.82 97.5 94.33 96.19 97.39 98.05 98.75 98.89 99.25 99.47 99.55 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 0 to 6 hours

2.5 -- 0.15 0.42 1.06 1.30 1.39 2.08 2.35 2.61 5.0 -- .50 .99 1.78 2.75 4.28 5.46 6.25 6.61 7.5 -- .86 1.55 2.50 4.07 6.75 8.59 10.16 10.60 

10.0 -- 1.21 2.12 3.22 5.17 8.92 11.27 14.06 14.60 12.5 -- 1.61 2.59 3.83 6.04 10.54 13.47 17.52 18.30 15.0 -- 2.02 3.06 4.44 6.91 12.16 15.67 20.97 22.01 17.5 -- 2.42 3.53 5.06 7.72 13.51 17.45 23.94 25.19 20.0 -- 2.83 3.88 5.52 8.50 14.62 19.00 25.98 27.54 22.5 -- 3.23 4.24 5.98 9.10 15.53 20.04 28.01 29.88 25.0 -- 3.63 4.49 6.27 9.67 16.65 21.18 29.60 31.58 27.5 -- 3.95 4.78 6.66 10.21 17.66 22.22 30.36 32.51 30.0 -- 4.26 5.06 7.06 10.89 18.60 23.26 31.13 33.43 32.5 -- 4.58 5.35 7.45 11.52 19.52 24.25 31.89 34.36 35.0 -- 4.90 5.54 7.87 12.30 20.41 25.22 32.15 34.80 37.5 -- 5.21 5.72 8.29 13.08 21.30 26.18 32.41 35.23 40.0 -- 5.53 5.98 8.69 13.92 22.01 26.94 32.65 35.64 42.5 -- 5.84 6.24 9.10 14.76 22.78 27.70 32.89 36.04 45.0 -- 6.16 6.50 9.50 15.60 23.55 28.46 33.13 36.45 47.5 -- 6.72 7.10 10.24 16.36 24.89 28.94 33.66 37.14 50.0 -- 7.28 8.00 10.98 17.12 25.51 29.43 34.20 37.83 52.5 -- 7.94 8.16 12.12 18.18 26.22 30.14 34.60 38.61 55.0 -- 8.61 8.68 12.90 19.01 26.63 30.49 34.80 38.97 57.5 -- 9.65 10.34 14.39 19.80 26.70 30.78 35.50 39.74 60.0 -- 10.69 12.01 15.88 21.01 27.00 31.37 36.20 40.52 62.5 -- 11.73 14.15 17.93 22.80 28.15 32.61 37.75 41.98 65.0 -- 13.38 16.35 20.06 24.18 29.41 33.58 39.38 43.60 67.5 -- 15.02 18.55 22.19 26.27 31.70 35.64 41.02 45.21 70.0 -- 17.33 21.17 24.62 29.21 35.06 38.73 43.55 47.67 72.5 -- 19.47 24.22 27.44 32.59 38.95 42.60 47.27 51.24 75.0 -- 21.95 27.24 30.36 36.19 43.21 47.31 52.26 56.08 77.5 -- 23.90 30.74 33.81 41.00 48.68 53.16 57.84 61.73 80.0 -- 26.13 34.50 37.75 46.37 54.47 59.29 63.96 67.73 82.5 -- 28.99 39.04 42.45 52.20 60.56 65.54 70.33 73.82 85.0 -- 34.91 44.78 48.36 58.12 66.65 72.11 76.46 79.90 87.5 -- 43.08 52.34 55.85 64.81 72.96 77.99 82.37 85.52 90.0 -- 54.07 61.20 64.27 71.97 79.31 83.92 87.64 90.17 92.5 -- 66.56 71.36 73.59 79.37 85.38 89.19 91.85 93.70 95.0 -- 79.99 82.48 83.79 86.93 91.02 93.77 95.54 96.80 97.5 -- 92.85 93.93 94.25 95.04 96.74 97.86 98.64 99.13 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 6 to 12 hours 2.5 0.43 0.78 0.95 1.11 1.96 3.28 3.91 5.87 7.73 

5.0 .96 2.10 2.49 2.90 4.58 6.81 9.10 11.95 13.82 7.5 1.61 3.45 4.05 4.70 7.19 10.38 13.94 17.32 19.01 

10.0 2.26 4.89 5.79 6.75 9.96 14.00 18.20 21.63 23.06 12.5 2.95 6.32 7.47 8.86 12.78 17.58 21.93 25.10 26.35 15.0 3.66 7.81 9.27 11.11 15.75 20.91 25.08 28.04 29.23 17.5 4.20 9.13 11.14 13.30 18.38 23.69 27.45 30.20 31.54 20.0 4.63 10.71 13.26 15.72 21.20 26.13 29.56 32.33 34.04 22.5 5.06 11.93 14.92 17.57 23.60 28.10 31.33 34.39 36.69 25.0 5.42 13.21 16.76 19.47 25.80 29.64 32.74 36.15 38.86 27.5 5.65 14.25 18.56 21.19 27.10 30.77 33.93 37.71 40.60 30.0 5.85 15.10 19.88 22.40 28.13 31.51 34.80 39.02 41.97 32.5 6.09 15.49 20.77 23.11 28.51 31.91 35.43 39.94 42.93 35.0 6.35 16.00 21.83 23.90 28.59 32.16 36.10 40.78 43.44 37.5 6.59 16.07 22.22 24.05 28.67 32.27 36.50 41.20 43.69 40.0 6.92 16.13 22.37 24.22 28.76 32.38 36.86 41.35 43.83 42.5 6.94 16.31 22.52 24.39 28.84 32.49 37.10 41.44 43.91 45.0 7.31 16.49 22.68 24.56 28.92 32.60 37.17 41.45 43.99 47.5 7.68 16.68 22.83 24.74 29.00 32.71 37.51 41.58 44.06 50.0 8.05 16.86 22.98 24.91 29.09 32.82 37.84 41.70 44.14 52.5 8.42 17.04 23.13 25.08 29.18 32.93 38.18 41.83 44.22 55.0 8.79 17.22 23.29 25.25 29.26 33.04 38.52 41.95 44.30 57.5 9.16 17.40 23.44 25.42 29.34 33.70 38.86 42.70 45.14 60.0 9.53 17.58 23.59 25.60 29.43 34.51 39.19 43.23 46.88 62.5 9.90 17.77 23.74 25.76 29.51 36.14 40.00 44.57 48.60 65.0 10.27 17.95 23.90 25.94 30.90 38.06 42.01 46.22 50.46 67.5 10.64 19.50 24.05 26.11 33.28 40.27 44.33 48.29 52.83 70.0 11.01 21.37 25.00 27.20 36.55 43.02 46.88 50.94 55.73 72.5 12.50 25.56 28.31 30.48 40.42 46.09 49.60 53.91 58.71 75.0 16.23 30.25 33.02 35.06 44.75 49.94 52.96 57.63 62.47 77.5 21.71 35.37 38.05 40.39 49.92 54.29 56.80 62.00 66.57 80.0 27.03 40.50 42.90 45.73 55.47 59.74 62.13 67.29 71.40 82.5 31.18 45.59 48.07 51.73 61.08 65.93 68.37 73.21 76.62 85.0 34.32 50.14 52.87 57.79 66.87 72.69 75.17 79.20 82.03 87.5 38.22 55.59 58.49 64.52 73.01 79.21 81.60 84.91 86.98 90.0 43.40 61.88 65.08 71.39 79.07 85.28 87.49 89.94 91.46 92.5 52.04 69.74 73.07 78.53 85.16 90.46 92.13 93.82 94.86 95.0 64.33 79.17 82.15 85.56 91.29 94.79 95.79 96.64 97.33 97.5 79.39 89.96 92.17 92.66 97.41 98.40 98.73 98.92 99.13 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 12 to 24 hours

2.5 0.35 0.98 0.97 1.36 2.12 2.60 3.90 4.69 5.64 5.0 .65 1.65 1.79 2.26 3.24 3.99 5.44 8.23 9.52 7.5 .86 2.20 2.58 3.14 4.33 5.35 6.81 10.96 12.70 

10.0 1.12 2.80 3.38 4.00 5.31 6.51 8.01 12.93 15.18 12.5 1.27 3.34 4.01 4.69 6.09 7.49 9.08 13.96 16.70 15.0 1.67 4.01 4.77 5.45 7.11 8.55 10.12 14.29 17.64 17.5 2.02 4.70 5.76 6.56 8.40 9.90 11.56 15.02 18.71 20.0 2.48 5.51 7.05 7.96 9.81 11.55 13.44 16.34 20.07 22.5 2.68 6.22 8.26 9.61 11.49 13.55 15.75 18.34 21.80 25.0 2.71 7.07 9.57 11.34 13.57 15.83 18.35 21.13 24.27 27.5 2.74 7.68 10.44 12.84 15.41 18.17 21.01 24.36 27.07 30.0 2.80 8.26 10.60 14.01 16.94 20.31 23.34 27.36 29.84 32.5 2.91 8.81 10.77 14.87 18.41 22.17 25.38 30.14 32.66 35.0 3.43 9.51 10.93 15.39 19.66 23.81 27.13 32.37 35.19 37.5 4.22 10.13 11.34 16.04 20.80 25.42 28.82 34.28 37.43 40.0 5.44 11.03 12.37 16.92 22.04 27.01 30.42 35.93 39.39 42.5 6.70 12.15 13.72 17.99 23.34 28.66 32.03 37.46 41.07 45.0 8.16 13.43 15.60 19.11 24.65 30.40 33.70 39.04 42.54 47.5 9.58 14.69 17.44 20.28 26.00 32.24 35.47 40.66 43.98 50.0 10.96 16.08 19.06 21.43 27.31 34.19 37.22 42.23 45.25 52.5 12.38 17.53 20.57 22.74 28.81 36.33 39.06 43.74 46.56 55.0 13.71 18.82 21.89 23.79 30.27 37.88 40.46 45.07 47.72 57.5 15.06 20.13 23.14 24.92 31.84 39.13 41.66 46.30 48.94 60.0 16.20 21.46 24.39 26.10 33.36 39.94 42.42 47.21 49.98 62.5 17.40 22.79 25.68 27.62 34.94 40.53 43.14 48.04 51.12 65.0 18.16 23.94 26.92 29.15 36.27 40.85 43.81 48.91 52.22 67.5 18.99 25.26 28.42 31.13 37.95 41.87 45.17 50.03 53.63 70.0 19.26 26.44 29.84 33.09 39.59 43.44 46.95 51.40 55.14 72.5 19.52 27.63 31.56 35.37 41.63 45.76 49.66 53.82 57.67 75.0 19.85 28.57 33.22 37.69 43.48 48.02 52.50 56.72 60.54 77.5 20.18 29.84 35.17 40.52 45.54 50.62 55.67 60.22 64.03 80.0 20.94 31.58 37.58 43.56 48.14 53.74 59.20 64.29 67.97 82.5 22.45 34.03 40.78 47.63 51.87 57.60 63.39 68.91 72.45 85.0 24.97 37.20 44.67 52.31 56.64 62.33 68.05 73.64 76.78 87.5 29.44 42.76 50.56 58.40 63.26 68.71 73.84 78.80 81.43 90.0 36.14 50.28 58.00 65.51 71.26 75.99 80.10 84.12 86.04 92.5 46.13 59.57 66.81 73.64 79.37 83.17 86.22 89.13 90.43 95.0 59.21 70.64 76.79 82.22 87.29 90.06 91.97 93.74 94.49 97.5 74.47 83.29 87.75 91.48 95.15 96.69 97.45 98.15 98.38 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 24 to 72 hours 2.5 0.59 1.02 1.45 1.74 2.23 3.39 5.06 7.94 9.92 

5.0 1.05 1.87 2.82 3.29 4.52 6.33 9.14 12.90 16.46 7.5 1.50 3.10 4.14 4.78 6.61 9.07 12.81 17.08 21.84 

10.0 1.93 4.28 5.44 6.23 8.43 11.40 15.82 20.26 25.63 12.5 2.31 5.41 6.70 7.63 10.03 13.24 18.03 22.36 27.75 15.0 2.84 6.48 7.91 8.95 11.56 15.04 20.00 24.05 28.89 17.5 3.57 7.47 9.02 10.15 12.94 16.72 21.66 25.49 29.65 20.0 4.47 8.54 10.17 11.39 14.41 18.36 23.33 27.18 30.55 22.5 5.52 9.72 11.39 12.68 15.92 19.97 24.87 28.86 31.75 25.0 6.77 11.15 12.75 14.07 17.50 21.68 26.52 30.85 33.50 27.5 8.19 12.84 14.32 15.64 19.01 23.32 28.09 32.84 35.42 30.0 9.50 14.74 16.13 17.36 20.58 24.99 29.66 34.87 37.37 32.5 10.74 16.86 18.09 19.13 22.18 26.63 31.12 36.63 39.19 35.0 11.78 18.65 19.79 20.90 23.78 28.25 32.66 38.25 40.68 37.5 12.69 19.95 21.14 22.48 25.30 29.74 34.18 39.54 41.75 40.0 13.29 20.97 22.27 23.87 26.86 31.26 35.65 40.79 42.74 42.5 13.70 21.58 23.11 25.06 28.31 32.73 37.05 41.83 43.66 45.0 13.80 21.85 23.71 26.12 29.72 34.24 38.49 42.91 44.49 47.5 13.85 22.31 24.43 27.02 31.09 35.77 39.93 44.03 45.53 50.0 13.90 22.92 25.24 27.85 32.44 37.35 41.40 45.22 46.65 52.5 14.24 23.56 26.15 28.69 33.78 38.83 42.94 46.40 47.68 55.0 14.88 24.55 27.27 29.63 35.25 40.33 44.46 47.69 48.77 57.5 15.89 25.35 28.27 30.42 36.47 41.63 45.80 49.07 50.10 60.0 17.21 26.26 29.48 31.29 37.58 42.88 47.12 50.54 51.51 62.5 18.58 27.27 30.78 32.43 38.71 44.01 48.35 51.96 53.05 65.0 19.74 28.17 31.91 33.71 39.88 45.03 49.44 53.39 54.73 67.5 21.06 28.95 33.04 35.11 41.01 46.15 50.62 54.88 56.43 70.0 22.59 30.17 34.40 36.94 42.51 47.63 52.01 56.33 58.04 72.5 24.62 31.67 35.91 39.06 44.24 49.39 53.75 57.99 59.84 75.0 26.98 33.96 38.12 41.61 46.62 51.88 56.20 60.35 62.26 77.5 29.58 37.07 41.12 44.71 49.53 55.20 59.36 63.43 65.34 80.0 32.55 40.97 44.66 48.25 53.16 59.07 63.21 67.23 69.22 82.5 35.97 45.72 49.10 52.41 57.42 63.55 67.85 71.87 73.93 85.0 39.68 51.10 54.19 57.17 62.52 68.54 72.98 77.02 79.12 87.5 44.87 57.06 59.93 62.61 68.08 73.75 78.22 82.18 84.21 90.0 52.10 63.89 66.42 68.76 74.05 79.14 83.42 86.99 88.84 92.5 61.10 71.78 73.97 75.94 80.30 84.66 88.46 91.33 92.77 95.0 71.73 80.45 82.29 83.86 86.54 89.97 93.15 95.06 95.97 97.5 83.82 89.84 91.23 92.39 92.81 95.28 97.53 98.35 98.63 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 0 to 72 hours

2.5 0.44 0.84 1.20 1.64 1.69 2.29 4.07 6.12 7.47 5.0 .95 1.78 2.39 2.93 3.95 4.91 8.14 10.99 12.86 7.5 1.37 2.66 3.53 4.18 5.98 7.33 11.75 15.26 17.48 

10.0 1.74 3.57 4.66 5.45 7.72 9.52 14.79 18.70 21.18 12.5 1.99 4.40 5.74 6.60 9.15 11.45 17.11 21.26 23.86 15.0 2.45 5.30 6.79 7.68 10.50 13.35 18.83 23.19 25.76 17.5 2.90 6.28 7.82 8.82 11.79 15.15 20.28 24.71 27.23 20.0 3.51 7.41 9.00 10.11 13.29 17.02 21.85 26.23 28.76 22.5 4.17 8.44 10.26 11.48 14.89 18.78 23.47 27.85 30.33 25.0 5.02 9.60 11.76 13.14 16.69 20.54 25.42 29.73 32.21 27.5 5.74 10.65 13.32 14.97 18.56 22.23 27.54 31.71 34.32 30.0 6.48 11.61 14.94 16.83 20.37 23.98 29.37 33.63 36.38 32.5 7.18 12.47 16.37 18.61 22.03 25.59 30.96 35.42 38.26 35.0 7.89 13.35 17.67 20.13 23.51 27.14 32.38 37.02 39.90 37.5 8.50 14.16 18.65 21.28 24.77 28.51 33.50 38.30 41.15 40.0 9.13 15.00 19.54 22.29 25.92 29.87 34.58 39.49 42.17 42.5 9.73 15.85 20.27 22.96 26.91 31.10 35.72 40.54 43.06 45.0 10.37 16.73 21.07 23.49 27.93 32.37 36.95 41.60 43.90 47.5 10.95 17.60 21.77 24.09 28.98 33.66 38.22 42.69 44.85 50.0 11.57 18.46 22.38 24.85 30.01 34.95 39.50 43.86 45.91 52.5 12.27 19.40 23.10 25.59 31.09 36.19 40.78 45.09 47.03 55.0 13.13 20.28 23.80 26.63 32.24 37.45 42.08 46.38 48.19 57.5 14.08 21.20 24.55 27.82 33.34 38.61 43.23 47.68 49.52 60.0 14.92 22.12 25.30 28.93 34.50 39.67 44.27 48.89 50.75 62.5 15.93 23.13 26.29 29.97 35.75 40.75 45.27 50.07 52.02 65.0 17.03 24.11 27.24 31.04 36.95 41.83 46.33 51.19 53.31 67.5 18.39 25.53 28.68 32.25 38.34 43.15 47.58 52.41 54.66 70.0 19.85 27.16 30.27 33.67 39.92 44.85 49.17 53.72 56.05 72.5 22.02 29.51 32.73 35.81 41.85 47.11 51.31 55.72 58.12 75.0 24.15 32.22 35.51 38.50 44.25 49.94 54.15 58.44 60.86 77.5 26.35 35.42 38.82 41.75 47.18 53.43 57.59 61.95 64.34 80.0 28.62 38.93 42.42 45.40 50.89 57.53 61.72 66.22 68.61 82.5 31.25 43.06 46.75 49.79 55.56 62.26 66.62 71.30 73.68 85.0 34.13 47.35 51.25 54.59 60.93 67.55 72.02 76.61 78.89 87.5 38.89 53.06 57.06 60.45 67.11 73.39 77.61 81.87 83.94 90.0 45.85 60.14 64.00 67.29 73.89 79.43 83.22 86.78 88.55 92.5 55.22 68.57 72.07 75.11 80.82 85.42 88.49 91.20 92.53 95.0 66.87 78.15 81.02 83.56 87.77 91.21 93.29 95.04 95.82 97.5 80.38 88.83 90.79 92.58 94.75 96.81 97.72 98.44 98.66 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 0 to 6 hours 2.5 0.57 1.88 2.08 2.29 3.21 4.08 5.74 6.87 8.29 

5.0 1.83 4.19 4.30 5.55 7.74 10.03 12.66 15.17 17.08 7.5 2.98 6.43 7.07 8.70 12.09 15.89 19.46 23.40 25.83 

10.0 4.13 8.77 9.83 11.92 16.33 21.73 26.41 31.77 34.61 12.5 5.28 11.17 12.52 15.03 20.37 27.40 33.28 39.81 43.08 15.0 6.52 13.54 15.19 18.19 24.34 32.57 39.79 47.61 51.29 17.5 7.68 15.66 17.49 21.05 28.17 37.05 45.58 54.35 58.28 20.0 8.96 17.94 20.00 24.16 32.05 41.29 50.98 60.16 64.32 22.5 10.39 20.02 22.55 27.03 35.67 44.94 55.52 64.79 69.29 25.0 11.99 22.62 25.64 30.44 39.45 48.52 59.46 68.71 73.25 27.5 13.61 25.24 28.74 33.59 43.18 52.10 62.81 71.65 76.08 30.0 15.35 28.40 32.21 37.38 47.10 55.86 66.04 74.59 78.92 32.5 17.18 31.39 35.48 40.95 50.74 59.43 68.81 77.27 81.23 35.0 19.03 34.47 38.78 45.09 54.85 63.02 71.55 79.88 83.42 37.5 20.87 36.32 41.43 48.32 58.24 66.07 73.82 82.01 85.23 40.0 22.58 38.14 44.03 51.82 61.65 69.10 76.14 83.97 86.88 42.5 24.27 39.23 46.47 54.34 64.18 71.63 77.96 85.24 87.89 45.0 26.05 40.64 49.00 56.87 66.66 73.93 79.79 86.30 88.82 47.5 27.91 42.33 51.43 58.80 68.39 75.94 81.29 87.07 89.43 50.0 29.78 44.92 54.00 60.89 70.36 77.94 82.83 87.82 90.11 52.5 31.98 47.68 56.56 62.62 71.67 79.48 84.12 88.51 90.70 55.0 33.99 51.22 59.24 64.80 73.39 80.93 85.49 89.29 91.33 57.5 36.02 54.66 61.80 66.89 75.00 82.35 86.66 90.05 91.92 60.0 37.76 58.02 64.38 69.06 76.76 83.79 87.93 90.88 92.57 62.5 39.45 61.22 66.91 71.30 78.42 85.06 89.06 91.66 93.16 65.0 41.11 64.42 69.45 73.65 80.30 86.41 90.20 92.46 93.78 67.5 43.57 67.36 71.97 75.85 81.97 87.74 91.25 93.24 94.37 70.0 46.33 70.26 74.53 78.03 83.66 88.93 92.26 94.00 94.98 72.5 50.64 73.14 77.10 80.24 85.32 90.06 93.13 94.70 95.54 75.0 55.94 76.04 79.71 82.50 87.06 91.24 94.01 95.42 96.14 77.5 61.89 78.79 82.31 84.72 88.72 92.38 94.80 96.06 96.68 80.0 67.60 81.53 84.78 86.93 90.39 93.46 95.63 96.70 97.22 82.5 73.38 84.29 87.20 89.11 91.99 94.52 96.38 97.28 97.72 85.0 78.09 86.87 89.44 91.12 93.45 95.51 97.10 97.83 98.19 87.5 82.29 89.33 91.53 92.95 94.73 96.41 97.74 98.32 98.60 90.0 86.01 91.76 93.44 94.65 95.97 97.25 98.31 98.76 98.96 92.5 89.75 94.09 95.32 96.30 97.20 98.08 98.80 99.13 99.28 95.0 93.41 96.26 97.12 97.78 98.34 98.85 99.28 99.46 99.55 97.5 97.17 98.45 98.91 99.20 99.49 99.63 99.76 99.77 99.81 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 6 to 12 hours

2.5 0.66 1.63 2.19 2.95 4.87 6.08 6.87 9.07 10.62 5.0 1.83 3.83 4.84 6.06 9.12 12.28 15.33 19.11 22.19 7.5 2.91 5.96 7.38 9.02 13.30 18.29 23.21 28.32 32.78 

10.0 3.98 8.14 10.01 12.04 17.50 23.87 29.95 36.49 42.02 12.5 5.02 10.14 12.40 14.90 21.31 28.70 35.46 43.29 49.51 15.0 6.05 12.12 14.81 17.64 24.89 32.88 40.29 48.98 55.52 17.5 6.99 13.81 16.90 20.14 27.73 36.16 44.17 53.48 60.03 20.0 7.97 15.52 19.07 22.61 30.33 38.83 47.61 57.53 63.77 22.5 8.91 16.91 20.87 24.71 32.51 41.05 50.88 60.89 66.80 25.0 9.88 18.46 22.80 26.83 34.73 43.07 53.95 63.96 69.56 27.5 10.77 19.85 24.35 28.63 36.60 44.76 56.71 66.92 72.22 30.0 11.61 21.11 25.86 30.30 38.53 46.45 59.14 69.69 74.79 32.5 12.33 22.04 26.86 31.61 40.10 47.94 61.22 71.91 77.04 35.0 12.92 23.06 27.92 32.87 41.68 49.64 63.12 73.95 78.97 37.5 13.23 23.76 28.51 33.69 42.96 51.30 64.73 75.64 80.48 40.0 13.64 24.42 29.15 34.52 44.24 53.14 66.24 76.92 81.47 42.5 13.86 25.10 29.68 35.19 45.36 54.95 67.65 77.90 82.04 45.0 14.24 26.00 30.46 36.03 46.50 56.94 68.99 78.86 82.43 47.5 14.81 26.80 31.16 36.90 47.63 58.83 70.26 79.71 82.79 50.0 15.61 27.85 32.29 38.21 49.03 60.79 71.63 80.55 83.13 52.5 16.61 29.16 33.71 39.77 50.48 62.73 72.93 81.38 83.63 55.0 18.00 30.88 35.47 41.66 52.40 64.70 74.31 82.19 84.23 57.5 19.41 32.78 37.47 43.71 54.55 66.67 75.81 83.02 84.93 60.0 20.96 35.06 39.87 46.22 56.91 68.68 77.27 83.85 85.71 62.5 22.72 37.62 42.40 48.77 59.38 70.72 78.74 84.71 86.61 65.0 24.41 40.28 45.06 51.48 62.06 72.80 80.21 85.54 87.51 67.5 26.33 42.87 47.80 54.43 64.74 74.92 81.66 86.51 88.48 70.0 28.62 45.44 50.75 57.62 67.63 77.07 83.09 87.49 89.46 72.5 31.66 48.23 53.87 60.73 70.49 79.17 84.55 88.59 90.48 75.0 35.21 51.35 57.36 64.12 73.38 81.33 86.07 89.73 91.50 77.5 39.55 55.11 61.28 67.70 76.43 83.58 87.66 90.98 92.53 80.0 44.18 59.68 65.87 71.53 79.45 85.73 89.23 92.20 93.56 82.5 49.39 65.20 70.99 75.65 82.51 87.91 90.86 93.47 94.60 85.0 54.82 71.20 76.36 79.99 85.66 90.06 92.47 94.68 95.59 87.5 61.07 77.32 81.62 84.33 88.77 92.16 94.05 95.84 96.55 90.0 67.68 82.97 86.48 88.40 91.62 94.05 95.52 96.91 97.44 92.5 75.21 88.18 90.75 92.09 94.24 95.87 96.90 97.88 98.24 95.0 83.13 92.83 94.46 95.36 96.58 97.52 98.15 98.74 98.97 97.5 91.32 97.03 97.80 98.33 98.76 99.10 99.32 99.52 99.64 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 12 to 24 hours 2.5 1.48 1.89 2.62 4.09 5.56 7.59 7.94 10.13 11.97 

5.0 2.95 4.94 6.25 7.26 11.83 15.49 17.64 21.50 24.46 7.5 4.42 8.00 9.91 12.13 18.03 23.18 26.81 31.95 35.82 

10.0 5.87 11.00 13.56 17.02 24.26 30.50 35.02 40.94 45.55 12.5 7.27 13.93 17.16 21.82 30.31 37.08 42.14 48.22 53.32 15.0 8.57 16.49 20.31 26.14 35.63 42.81 48.44 54.21 59.39 17.5 9.63 18.63 23.06 29.87 40.17 47.50 53.72 59.20 64.05 20.0 10.66 20.49 25.48 33.08 43.98 51.47 58.56 63.76 68.11 22.5 11.67 22.06 27.53 35.39 46.96 54.64 62.97 68.17 71.83 25.0 12.49 23.35 29.26 37.06 49.07 57.26 66.87 72.63 75.58 27.5 13.12 24.67 30.95 38.52 50.92 59.40 70.10 76.69 79.25 30.0 13.67 25.79 32.37 39.68 52.12 60.90 72.40 79.87 82.42 32.5 13.94 26.68 33.37 40.43 52.84 61.56 73.57 82.05 84.91 35.0 14.20 27.61 34.41 41.31 53.36 62.15 74.16 83.23 86.69 37.5 14.65 28.48 35.17 42.02 53.61 62.44 74.34 83.51 87.66 40.0 15.34 29.42 35.97 42.66 53.70 62.75 74.49 83.63 88.02 42.5 16.21 30.47 36.93 43.47 53.85 63.36 74.63 83.75 88.23 45.0 17.35 31.69 38.17 44.41 54.30 64.34 74.78 83.88 88.32 47.5 18.54 33.00 39.39 45.30 54.88 65.12 75.40 84.00 88.45 50.0 19.67 34.49 40.88 46.49 55.98 66.17 76.26 84.12 88.72 52.5 21.02 36.20 42.65 48.06 57.57 67.42 77.30 85.05 89.27 55.0 22.63 38.49 44.86 50.00 59.55 68.89 78.52 86.07 89.84 57.5 24.70 41.20 47.41 52.55 61.73 70.76 79.90 87.34 90.67 60.0 26.98 43.73 50.07 55.27 64.16 73.06 81.38 88.58 91.55 62.5 29.74 46.34 52.77 57.95 66.61 75.36 82.68 89.72 92.43 65.0 32.48 48.66 55.12 60.32 68.91 77.49 83.99 90.67 93.14 67.5 35.30 50.52 57.02 62.35 71.04 79.34 85.29 91.54 93.81 70.0 37.77 52.15 58.68 63.91 73.18 80.82 86.42 92.14 94.27 72.5 40.28 54.33 60.51 65.67 75.28 82.16 87.37 92.72 94.69 75.0 42.52 56.76 62.56 67.62 77.32 83.43 88.40 93.28 95.08 77.5 44.90 59.67 65.09 69.97 79.37 84.77 89.43 93.89 95.49 80.0 47.27 63.00 68.03 72.56 81.47 86.17 90.49 94.49 95.92 82.5 50.17 66.82 71.40 75.59 83.64 87.67 91.63 95.15 96.39 85.0 53.29 70.64 74.94 78.68 85.80 89.19 92.81 95.81 96.87 87.5 57.60 74.85 78.83 82.09 88.04 90.85 94.01 96.51 97.38 90.0 63.11 79.41 82.85 85.56 90.37 92.56 95.21 97.20 97.91 92.5 69.98 84.29 87.04 89.21 92.78 94.38 96.41 97.93 98.45 95.0 77.90 89.30 91.17 92.82 95.27 96.24 97.62 98.66 98.99 97.5 86.94 94.61 95.41 96.51 97.84 98.15 98.84 99.41 99.55 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 24 to 72 hours

2.5 1.35 1.70 2.10 2.63 4.21 6.34 9.16 12.26 14.52 5.0 2.23 4.15 5.03 6.27 9.09 13.14 18.05 23.88 27.40 7.5 3.05 6.41 7.75 9.61 13.58 19.21 26.00 34.16 38.81 

10.0 3.88 8.36 10.07 12.49 17.46 24.29 32.73 42.87 48.46 12.5 4.68 9.84 11.91 14.76 20.61 28.20 37.99 49.52 55.79 15.0 5.45 11.02 13.51 16.69 23.19 31.07 41.94 54.06 60.70 17.5 6.18 11.88 14.75 18.17 25.10 32.93 44.53 56.96 63.93 20.0 6.97 12.73 15.95 19.61 26.77 34.36 46.47 58.97 65.94 22.5 7.74 13.54 17.15 20.93 28.28 35.43 47.72 59.79 66.52 25.0 8.58 14.57 18.44 22.35 29.79 36.48 48.97 60.18 66.68 27.5 9.51 15.84 19.86 23.75 31.36 37.85 50.11 60.55 66.83 30.0 10.58 17.28 21.48 25.31 33.03 39.45 51.44 60.95 66.99 32.5 11.63 18.69 23.08 26.78 34.70 41.11 52.79 61.59 67.15 35.0 12.73 20.19 24.68 28.34 36.39 43.08 54.53 62.96 67.30 37.5 13.83 21.55 26.26 29.82 37.99 45.11 56.04 64.57 68.00 40.0 15.00 22.80 27.92 31.39 39.56 47.02 57.59 66.29 69.25 42.5 16.11 24.06 29.59 32.94 41.06 48.98 59.06 68.08 71.19 45.0 17.35 25.49 31.36 34.66 42.63 50.99 60.41 69.80 73.12 47.5 18.69 27.16 33.35 36.54 44.39 52.95 61.68 71.35 74.59 50.0 19.96 29.50 35.51 38.69 46.33 54.92 63.28 72.86 76.09 52.5 21.17 32.47 38.12 41.19 48.30 56.89 65.02 74.34 77.54 55.0 22.58 35.42 40.73 43.73 50.45 58.87 66.99 75.88 79.34 57.5 24.00 38.02 43.03 46.13 52.70 60.97 69.29 77.37 81.19 60.0 25.38 40.31 44.96 48.39 54.82 63.00 71.56 78.77 83.16 62.5 26.71 41.96 46.67 50.46 56.91 65.04 73.66 80.21 85.01 65.0 28.01 42.88 47.60 52.03 58.84 67.01 75.51 81.69 86.65 67.5 29.31 43.91 48.58 53.62 60.73 68.89 77.14 83.08 88.00 70.0 30.67 45.19 49.89 55.27 62.43 70.67 78.52 84.44 89.17 72.5 32.21 46.80 51.66 57.19 64.01 72.47 79.87 85.83 90.13 75.0 34.46 48.80 53.84 59.33 65.61 74.25 81.12 87.23 90.96 77.5 37.29 51.45 56.70 61.86 67.73 76.14 82.50 88.55 91.79 80.0 40.54 54.36 59.93 64.74 70.09 78.08 83.92 89.80 92.54 82.5 44.75 58.00 63.74 68.13 72.99 80.30 85.56 91.08 93.40 85.0 49.83 62.26 67.97 71.79 76.42 82.67 87.31 92.32 94.33 87.5 55.61 67.15 72.62 75.92 80.29 85.32 89.27 93.59 95.32 90.0 62.44 72.58 77.60 80.43 84.29 88.20 91.39 94.96 96.35 92.5 70.64 79.03 82.85 85.19 88.48 91.30 93.69 96.39 97.41 95.0 79.72 86.09 88.16 90.03 92.53 94.44 96.05 97.80 98.40 97.5 89.52 93.52 93.59 95.02 96.63 97.71 98.55 99.26 99.39 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 0 to 72 hours 2.5 1.12 2.11 2.63 3.37 4.76 6.36 7.80 10.30 12.19 

5.0 2.36 4.40 5.54 6.89 9.80 13.57 16.94 21.32 24.50 7.5 3.58 6.65 8.39 10.36 14.73 20.47 25.49 31.42 35.63 

10.0 4.77 8.88 11.23 13.80 19.53 26.82 33.08 40.20 45.13 12.5 5.83 10.95 13.87 16.98 23.97 32.39 39.54 47.41 52.68 15.0 6.78 12.83 16.23 19.82 27.91 37.18 45.03 53.27 58.46 17.5 7.62 14.45 18.21 22.19 30.95 40.97 49.36 57.88 62.88 20.0 8.43 15.98 20.07 24.31 33.47 44.07 52.94 61.82 66.70 22.5 9.14 17.34 21.65 26.13 35.47 46.49 55.70 65.09 69.87 25.0 9.93 18.69 23.22 27.91 37.17 48.51 57.87 67.89 72.74 27.5 10.78 20.05 24.73 29.61 38.69 50.23 59.62 70.14 75.26 30.0 11.64 21.46 26.28 31.27 40.28 51.76 61.06 71.88 77.17 32.5 12.46 22.73 27.61 32.78 41.76 53.08 62.24 73.04 78.30 35.0 13.33 24.02 29.02 34.27 43.35 54.53 63.71 74.08 79.19 37.5 14.14 25.21 30.24 35.53 44.83 55.80 65.17 74.98 79.73 40.0 14.94 26.43 31.54 36.82 46.35 57.10 66.62 75.91 80.24 42.5 15.78 27.49 32.75 38.05 47.83 58.32 68.00 76.88 80.85 45.0 16.74 28.73 34.20 39.39 49.42 59.56 69.36 77.98 81.71 47.5 17.87 30.12 35.73 40.84 51.02 60.69 70.35 78.93 82.53 50.0 19.27 31.96 37.58 42.56 52.81 62.10 71.57 79.95 83.48 52.5 20.90 34.07 39.66 44.48 54.70 63.56 72.84 81.07 84.49 55.0 22.65 36.56 42.08 46.77 56.79 65.35 74.29 82.26 85.58 57.5 24.45 39.02 44.50 49.17 59.01 67.42 75.88 83.53 86.72 60.0 26.29 41.34 46.86 51.61 61.28 69.65 77.65 84.89 88.01 62.5 28.05 43.37 49.13 54.08 63.55 71.89 79.27 86.21 89.25 65.0 29.68 45.08 51.04 56.23 65.74 74.06 80.84 87.36 90.39 67.5 31.48 46.74 52.80 58.10 67.83 76.07 82.28 88.44 91.38 70.0 33.28 48.52 54.52 59.82 69.69 77.82 83.65 89.39 92.21 72.5 35.29 50.63 56.44 61.56 71.56 79.49 84.98 90.30 92.89 75.0 37.72 53.11 58.65 63.47 73.36 81.02 86.29 91.19 93.48 77.5 40.62 56.16 61.45 65.95 75.40 82.64 87.62 92.10 94.08 80.0 43.83 59.55 64.59 68.82 77.52 84.23 88.99 92.99 94.71 82.5 47.86 63.50 68.30 72.25 80.02 86.04 90.41 93.92 95.40 85.0 52.38 67.89 72.37 76.01 82.65 87.90 91.83 94.84 96.10 87.5 57.81 72.73 76.76 80.01 85.56 89.92 93.27 95.76 96.84 90.0 64.30 77.84 81.31 84.09 88.51 91.95 94.72 96.69 97.56 92.5 72.00 83.25 86.07 88.29 91.62 94.03 96.18 97.66 98.27 95.0 80.56 88.71 90.74 92.37 94.65 96.01 97.62 98.61 98.95 97.5 89.98 94.26 95.49 96.50 97.74 98.00 99.07 99.60 99.64 

Supplement 4. Untrimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 

First-quartile storms; storm duration 0 to 6 hours

2.5 1.36 2.38 2.70 3.06 4.30 5.98 8.25 10.50 10.96 5.0 4.51 7.64 8.57 9.73 11.71 13.90 16.76 20.46 21.98 7.5 7.81 12.91 14.91 16.38 19.03 21.71 25.26 30.23 32.71 

10.0 11.50 18.31 21.08 22.94 26.36 29.80 34.02 40.05 43.18 12.5 15.61 23.69 27.05 29.27 33.46 37.68 42.54 49.24 52.90 15.0 20.14 29.15 32.89 35.50 40.35 45.42 50.80 57.55 61.26 17.5 24.67 34.21 38.37 41.37 46.72 52.52 58.20 64.42 67.96 20.0 29.35 39.07 43.51 46.74 52.65 59.00 64.66 70.18 73.32 22.5 33.59 43.56 48.24 51.64 57.80 64.30 69.98 74.62 77.31 25.0 37.78 48.07 52.79 56.29 62.38 68.63 74.24 78.04 80.13 27.5 41.40 51.81 56.60 60.25 66.22 72.04 77.42 80.74 82.45 30.0 44.66 55.26 59.98 63.67 69.59 75.08 80.16 83.19 84.57 32.5 47.69 58.52 63.13 66.86 72.40 77.58 82.39 85.10 86.39 35.0 50.75 61.46 65.96 69.65 74.94 79.90 84.42 86.91 88.11 37.5 53.27 63.70 68.19 71.85 76.99 82.05 86.16 88.49 89.70 40.0 55.88 66.04 70.41 73.91 78.85 83.87 87.64 89.80 91.05 42.5 58.46 68.19 72.45 75.86 80.40 85.16 88.65 90.66 91.92 45.0 61.01 69.97 74.27 77.56 81.86 86.33 89.59 91.49 92.65 47.5 63.16 71.67 75.95 79.09 83.03 87.25 90.21 92.07 93.17 50.0 65.58 73.44 77.73 80.71 84.32 88.10 90.89 92.70 93.69 52.5 67.81 74.99 79.22 82.00 85.44 88.92 91.50 93.20 94.16 55.0 69.75 76.50 80.68 83.20 86.57 89.76 92.15 93.74 94.69 57.5 71.29 78.04 82.11 84.38 87.59 90.52 92.70 94.19 95.15 60.0 72.82 79.56 83.52 85.60 88.72 91.35 93.31 94.66 95.61 62.5 73.84 80.87 84.72 86.65 89.70 92.05 93.78 95.03 95.97 65.0 74.71 82.24 86.08 87.90 90.73 92.80 94.31 95.46 96.34 67.5 75.68 83.59 87.31 89.08 91.66 93.47 94.77 95.85 96.65 70.0 76.66 84.82 88.36 90.09 92.56 94.10 95.24 96.26 96.97 72.5 77.64 86.00 89.30 90.95 93.27 94.64 95.65 96.64 97.25 75.0 78.94 87.25 90.41 91.98 94.02 95.24 96.13 97.03 97.56 77.5 80.32 88.44 91.37 92.85 94.65 95.74 96.55 97.42 97.86 80.0 81.81 89.53 92.33 93.68 95.26 96.25 96.99 97.80 98.14 82.5 83.62 90.74 93.34 94.50 95.83 96.75 97.40 98.16 98.42 85.0 85.66 91.95 94.42 95.34 96.44 97.27 97.85 98.52 98.71 87.5 87.80 93.18 95.34 96.00 96.98 97.73 98.25 98.83 98.97 90.0 90.00 94.48 96.33 96.69 97.51 98.18 98.64 99.10 99.20 92.5 92.43 95.88 97.37 97.47 98.10 98.64 99.01 99.35 99.43 95.0 94.89 97.29 97.82 98.34 98.74 99.09 99.37 99.58 99.63 97.5 97.46 98.76 99.00 99.25 99.39 99.54 99.71 99.81 99.85 
First-quartile storms; storm duration 6 to 12 hours 2.5 1.87 4.12 4.93 6.11 8.31 9.06 10.08 13.11 16.22 

5.0 5.77 9.61 11.22 12.69 15.91 18.27 22.24 26.66 30.77 7.5 9.48 15.01 17.44 19.16 23.25 27.01 33.28 38.75 43.57 

10.0 13.15 20.56 23.71 25.64 30.61 35.44 42.96 49.06 54.34 12.5 16.95 25.90 29.58 31.67 37.34 42.86 50.67 57.09 62.62 15.0 20.74 31.01 35.10 37.34 43.45 49.45 57.01 63.28 68.71 17.5 24.54 35.69 39.92 42.31 48.65 54.77 61.77 67.77 73.00 20.0 28.55 39.98 44.13 46.74 53.33 59.53 65.88 71.68 76.66 22.5 32.55 43.80 47.77 50.70 57.23 63.30 69.16 74.76 79.35 25.0 36.56 47.27 51.26 54.49 60.96 66.81 72.13 77.54 81.56 27.5 40.57 50.44 54.41 57.90 64.46 69.99 74.81 80.04 83.47 30.0 44.10 53.41 57.39 61.05 67.64 72.95 77.32 82.20 84.99 32.5 47.38 56.13 60.43 64.08 70.50 75.48 79.49 83.93 86.11 35.0 50.34 58.41 63.43 66.82 73.03 77.78 81.35 85.49 87.23 37.5 52.58 60.67 66.20 69.30 75.12 79.63 83.06 86.87 88.33 40.0 54.10 62.59 68.54 71.43 76.61 80.89 84.32 88.00 89.27 42.5 55.20 64.27 70.69 73.29 77.85 81.84 85.31 88.95 90.17 45.0 55.67 65.71 72.35 74.77 78.80 82.52 86.05 89.73 90.95 47.5 55.78 67.27 73.66 76.00 79.72 83.14 86.76 90.41 91.59 50.0 55.85 68.50 74.71 77.00 80.47 83.65 87.27 90.92 92.10 52.5 55.93 69.64 75.85 78.07 81.39 84.27 87.87 91.38 92.73 55.0 56.04 70.62 76.72 79.00 82.08 84.85 88.41 91.83 93.28 57.5 56.42 71.75 77.59 79.88 82.79 85.53 89.02 92.29 93.92 60.0 57.07 72.76 78.26 80.66 83.36 86.15 89.62 92.76 94.56 62.5 57.67 73.87 78.80 81.26 83.95 86.82 90.24 93.22 95.18 65.0 58.00 75.03 79.27 81.69 84.43 87.56 90.87 93.72 95.72 67.5 58.25 76.21 79.75 82.09 85.09 88.30 91.53 94.22 96.25 70.0 58.50 77.28 80.34 82.66 85.74 88.97 92.11 94.66 96.67 72.5 58.75 78.32 81.04 83.25 86.61 89.72 92.70 95.10 97.05 75.0 59.00 79.33 81.67 83.97 87.56 90.52 93.32 95.55 97.39 77.5 59.25 80.46 82.43 84.80 88.60 91.31 93.94 96.01 97.67 80.0 59.50 81.63 83.39 85.84 89.67 92.15 94.55 96.47 97.91 82.5 60.88 83.05 84.45 86.95 90.88 93.09 95.22 96.94 98.14 85.0 63.92 84.77 85.89 88.39 92.11 94.05 95.91 97.41 98.38 87.5 68.70 86.79 87.90 90.07 93.36 95.03 96.59 97.89 98.62 90.0 74.65 89.01 90.12 91.94 94.66 96.05 97.28 98.35 98.87 92.5 81.25 91.53 92.52 93.88 96.01 97.10 97.96 98.81 99.12 95.0 88.04 94.18 94.96 95.87 97.37 98.16 98.64 99.27 99.40 97.5 94.58 96.89 97.38 97.86 98.72 99.20 99.31 99.71 99.66 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First-quartile storms; storm duration 12 to 24 hours

2.5 2.16 4.68 6.38 7.72 7.88 8.79 10.99 13.98 15.53 5.0 6.35 10.61 13.23 14.94 16.76 18.97 22.71 27.35 29.97 7.5 10.81 16.51 20.00 22.08 25.35 28.52 33.47 39.47 43.11 

10.0 15.85 22.66 26.81 29.21 33.28 36.94 42.62 49.79 54.20 12.5 21.43 28.71 33.21 35.87 40.38 44.09 49.88 57.97 62.83 15.0 27.39 34.63 39.24 42.02 46.91 50.46 55.93 64.29 69.29 17.5 33.27 40.23 44.51 47.38 52.57 55.96 60.92 68.90 73.68 20.0 38.71 45.29 49.15 52.11 57.78 61.09 65.37 72.68 76.84 22.5 42.95 49.36 52.90 56.27 62.63 66.13 69.73 75.97 79.40 25.0 45.96 52.58 55.98 59.98 67.09 71.09 74.23 79.20 81.83 27.5 47.89 54.85 58.20 62.86 70.72 75.44 78.44 82.36 84.29 30.0 49.05 56.28 59.75 64.96 73.43 78.79 81.98 85.29 86.77 32.5 49.71 57.14 60.56 66.36 75.12 81.18 84.95 87.90 89.21 35.0 50.48 58.03 61.44 67.37 76.22 82.70 87.14 90.04 91.29 37.5 51.35 58.81 62.24 68.06 76.90 83.43 88.52 91.54 92.81 40.0 52.37 59.82 63.31 68.92 77.45 83.90 89.40 92.58 93.85 42.5 53.47 60.94 64.78 69.91 78.03 84.48 90.09 93.32 94.56 45.0 54.64 62.31 66.80 71.22 78.87 85.20 90.56 93.80 94.98 47.5 55.80 63.61 68.38 72.59 79.69 85.97 90.95 94.13 95.24 50.0 57.08 65.10 70.01 74.04 80.46 86.82 91.33 94.40 95.51 52.5 58.24 66.48 71.32 75.43 81.23 87.66 91.70 94.62 95.71 55.0 59.39 67.86 72.39 76.76 82.02 88.43 92.04 94.81 95.85 57.5 60.47 69.03 73.27 77.88 82.70 89.11 92.36 94.99 96.00 60.0 61.37 70.15 74.34 78.78 83.24 89.61 92.67 95.17 96.14 62.5 62.01 70.91 75.14 79.29 83.78 89.99 92.99 95.38 96.27 65.0 62.67 71.52 75.90 79.61 84.37 90.28 93.28 95.57 96.41 67.5 63.00 71.89 76.37 79.84 84.92 90.55 93.59 95.78 96.58 70.0 63.35 72.06 76.43 79.93 85.48 90.77 93.91 96.01 96.75 72.5 63.91 72.34 76.61 80.19 86.19 91.07 94.21 96.24 96.94 75.0 64.87 73.09 77.09 80.73 86.84 91.39 94.47 96.44 97.12 77.5 66.37 74.37 78.08 81.61 87.54 91.81 94.76 96.66 97.31 80.0 68.67 76.30 79.60 82.83 88.29 92.23 95.03 96.84 97.49 82.5 71.43 78.92 81.76 84.50 89.28 92.79 95.36 97.06 97.68 85.0 74.63 81.77 84.10 86.32 90.33 93.44 95.75 97.31 97.89 87.5 78.15 84.81 86.71 88.43 91.60 94.26 96.25 97.62 98.14 90.0 81.80 87.79 89.30 90.61 93.00 95.15 96.83 97.98 98.42 92.5 85.48 90.72 91.90 92.91 94.65 96.23 97.54 98.44 98.78 95.0 89.14 93.53 94.39 95.20 96.35 97.33 98.28 98.92 99.16 97.5 92.85 96.39 96.94 97.55 98.15 98.52 99.10 99.45 99.58 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First-quartile storms; storm duration 24 to 72 hours 2.5 2.94 4.38 5.18 6.33 8.55 10.98 14.98 19.44 21.29 

5.0 6.58 10.93 12.66 14.39 17.72 21.51 26.81 32.97 35.68 7.5 10.19 16.95 19.44 21.83 26.21 31.09 37.30 44.77 48.18 

10.0 13.69 22.12 25.13 28.22 33.53 39.40 46.37 54.68 58.57 12.5 17.09 26.61 29.80 33.44 39.46 46.14 53.61 62.42 66.42 15.0 20.31 30.40 33.86 37.94 44.46 51.40 59.31 67.90 71.77 17.5 23.41 33.37 37.12 41.35 48.27 55.29 63.78 72.03 75.67 20.0 26.40 35.99 39.76 44.05 51.18 58.26 67.31 75.28 78.81 22.5 29.26 38.61 42.35 46.42 53.41 60.21 69.39 77.55 81.02 25.0 32.16 41.18 44.71 48.70 55.41 61.57 70.44 78.88 82.52 27.5 35.11 43.89 46.74 50.67 56.95 62.48 70.80 79.20 83.47 30.0 37.98 46.72 48.80 52.74 58.27 63.17 71.00 79.31 83.78 32.5 41.37 49.92 51.87 55.38 59.90 64.10 72.00 79.48 83.86 35.0 44.99 53.45 55.26 58.39 62.23 65.74 72.50 79.50 84.23 37.5 48.52 57.00 58.84 61.40 64.67 68.03 73.00 80.75 85.28 40.0 51.90 60.42 62.38 64.37 67.26 70.84 75.00 82.85 87.03 42.5 54.94 63.22 65.40 66.87 69.70 73.84 77.26 85.41 89.14 45.0 56.77 65.19 67.24 68.60 71.79 76.66 80.58 87.90 91.25 47.5 57.50 65.30 67.50 69.65 73.07 78.87 83.27 89.92 92.87 50.0 57.70 65.50 67.80 70.13 73.85 80.25 85.11 91.13 93.85 52.5 57.90 65.70 68.10 70.23 74.25 81.03 86.02 91.67 94.21 55.0 58.15 65.90 68.40 70.35 74.68 81.47 86.64 92.00 94.38 57.5 58.30 66.10 68.60 70.54 75.10 81.72 86.87 92.06 94.40 60.0 58.50 66.40 68.80 70.80 75.68 81.99 87.06 92.18 94.53 62.5 58.70 66.70 69.00 71.45 76.48 82.53 87.43 92.38 94.75 65.0 58.90 67.00 69.25 72.33 77.51 83.26 88.08 92.70 95.10 67.5 59.00 67.37 69.53 73.32 78.58 84.15 88.73 93.02 95.39 70.0 59.22 68.56 70.77 74.36 79.75 85.11 89.49 93.45 95.75 72.5 60.34 69.88 72.18 75.42 80.89 86.07 90.31 93.84 96.06 75.0 61.79 71.07 73.52 76.34 81.95 86.96 91.10 94.28 96.37 77.5 63.68 72.52 75.00 77.31 82.92 87.75 91.81 94.71 96.63 80.0 65.74 74.01 76.41 78.27 83.86 88.48 92.45 95.14 96.93 82.5 68.04 75.47 77.71 79.32 84.80 89.34 93.14 95.60 97.22 85.0 70.80 77.20 79.29 80.73 85.79 90.18 93.87 96.11 97.53 87.5 73.83 79.47 81.30 82.61 87.00 91.03 94.67 96.65 97.86 90.0 77.35 82.19 83.80 85.03 88.72 92.23 95.54 97.25 98.23 92.5 81.65 85.64 87.08 88.21 91.11 93.95 96.58 97.93 98.64 95.0 86.62 89.79 91.07 92.09 94.11 96.03 97.81 98.66 99.10 97.5 92.06 94.41 95.46 96.34 97.65 98.58 99.11 99.45 99.60 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First-quartile storms; storm duration 0 to 72 hours

2.5 1.93 4.66 5.90 7.04 8.56 8.70 11.05 14.56 16.67 5.0 6.12 10.29 12.27 13.95 16.55 18.81 22.71 27.75 30.96 7.5 10.29 15.85 18.54 20.74 24.33 28.27 33.39 39.61 43.68 

10.0 14.60 21.60 24.85 27.53 31.87 36.71 42.70 49.76 54.37 12.5 18.93 27.22 30.87 33.86 38.81 43.93 50.29 57.88 62.71 15.0 23.41 32.68 36.52 39.71 45.11 50.35 56.58 64.19 68.88 17.5 27.83 37.75 41.54 44.80 50.42 55.74 61.73 68.89 73.19 20.0 32.04 42.38 46.00 49.23 55.07 60.57 66.29 72.87 76.62 22.5 35.78 46.19 49.63 52.82 59.02 64.85 70.25 76.14 79.36 25.0 39.17 49.39 52.60 55.85 62.30 68.65 73.90 79.05 81.77 27.5 41.95 51.90 55.00 58.26 64.90 71.70 77.12 81.70 84.00 30.0 44.31 53.92 57.00 60.22 67.07 74.09 79.71 84.03 86.05 32.5 46.54 55.75 58.81 61.90 68.77 75.85 81.70 85.99 87.89 35.0 48.69 57.82 60.83 63.76 70.31 77.23 83.36 87.66 89.50 37.5 50.63 59.87 62.91 65.70 71.98 78.42 84.67 88.98 90.81 40.0 52.50 62.03 65.02 67.71 73.80 79.62 85.79 90.04 91.89 42.5 54.19 64.09 66.97 69.76 75.59 80.86 86.82 90.96 92.75 45.0 55.64 65.91 68.75 71.75 77.37 82.20 87.84 91.73 93.42 47.5 56.81 67.23 70.06 73.32 78.92 83.43 88.70 92.36 93.96 50.0 57.89 68.34 71.13 74.64 80.15 84.59 89.50 92.93 94.40 52.5 58.78 69.07 71.97 75.73 81.11 85.59 90.18 93.40 94.76 55.0 59.59 69.69 72.74 76.56 81.83 86.42 90.76 93.75 95.08 57.5 60.30 70.23 73.45 77.28 82.50 87.12 91.29 94.07 95.37 60.0 60.92 70.78 74.19 77.95 83.09 87.75 91.77 94.38 95.64 62.5 61.43 71.36 74.90 78.54 83.69 88.28 92.16 94.67 95.90 65.0 61.97 72.08 75.71 79.18 84.35 88.85 92.61 94.98 96.15 67.5 62.39 72.78 76.53 79.82 85.11 89.46 93.02 95.30 96.39 70.0 62.92 73.54 77.32 80.44 85.85 90.10 93.41 95.63 96.65 72.5 63.62 74.42 78.19 81.18 86.67 90.81 93.80 95.98 96.90 75.0 64.64 75.28 79.08 81.94 87.47 91.53 94.21 96.31 97.14 77.5 66.09 76.32 80.07 82.81 88.25 92.22 94.61 96.64 97.38 80.0 68.05 77.52 81.18 83.82 88.97 92.87 95.03 96.95 97.62 82.5 70.36 78.91 82.47 85.02 89.81 93.54 95.49 97.27 97.84 85.0 73.14 80.59 83.99 86.39 90.65 94.25 95.99 97.60 98.09 87.5 76.44 82.82 86.00 88.21 91.72 95.01 96.55 97.94 98.36 90.0 80.08 85.43 88.28 90.21 93.00 95.84 97.16 98.30 98.64 92.5 84.23 88.62 90.93 92.55 94.60 96.82 97.84 98.70 98.96 95.0 88.89 92.30 93.91 95.13 96.38 97.90 98.56 99.13 99.28 97.5 93.81 96.28 97.12 97.91 98.43 99.02 99.31 99.58 99.61 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 0 to 6 hours 2.5 0.10 0.20 0.30 0.50 0.70 0.90 1.10 1.44 2.18 

5.0 .72 1.14 1.42 2.00 2.29 2.73 3.52 4.74 5.53 7.5 1.30 2.05 2.63 3.53 4.37 5.06 6.23 8.02 8.85 

10.0 2.03 3.26 3.97 5.17 6.51 7.49 9.12 11.30 12.20 12.5 2.77 4.48 5.23 6.83 8.64 9.94 12.07 14.48 15.45 15.0 3.55 5.86 6.62 8.69 10.98 12.69 15.27 18.00 19.11 17.5 4.18 7.12 8.10 10.80 13.66 15.81 18.82 21.84 23.12 20.0 4.77 8.54 9.96 13.42 16.70 19.37 22.84 26.13 27.74 22.5 5.65 10.28 12.25 16.34 20.00 23.19 27.14 30.94 33.08 25.0 6.64 12.50 15.21 19.83 23.73 27.49 31.90 36.25 39.25 27.5 8.04 15.39 18.85 23.55 27.69 31.88 36.84 41.62 45.40 30.0 9.67 18.91 23.05 27.71 32.10 36.72 42.10 47.17 51.58 32.5 11.77 22.93 27.62 32.01 36.57 41.49 47.23 52.62 57.36 35.0 14.45 27.19 32.30 36.53 41.33 46.42 52.50 57.70 62.39 37.5 17.80 31.67 37.01 40.97 46.10 51.32 57.64 62.64 66.70 40.0 21.30 35.81 41.24 45.20 50.59 55.98 62.44 67.46 70.75 42.5 25.27 40.08 45.39 49.07 54.68 60.09 66.73 71.90 74.50 45.0 29.31 44.21 49.37 52.89 58.76 64.20 70.84 76.00 77.99 47.5 32.96 48.00 53.00 56.29 62.27 67.84 74.34 79.56 81.15 50.0 36.44 51.57 56.21 59.32 65.35 70.95 77.30 82.52 83.88 52.5 40.23 55.37 59.63 62.36 68.28 73.81 79.90 84.78 86.03 55.0 44.28 58.99 62.84 65.36 70.99 76.52 82.29 86.44 87.57 57.5 48.21 62.35 65.78 68.08 73.42 78.83 84.25 87.70 88.75 60.0 52.18 65.61 68.73 70.80 75.90 80.96 85.93 88.86 89.78 62.5 56.78 68.84 71.80 73.63 78.45 83.08 87.58 89.92 90.76 65.0 61.57 71.92 74.75 76.46 81.17 85.27 89.14 91.03 91.79 67.5 66.08 74.81 77.60 79.20 83.98 87.37 90.49 92.23 92.91 70.0 70.72 77.80 80.47 81.97 86.60 89.37 91.83 93.35 93.96 72.5 75.31 80.77 83.21 84.58 88.80 91.23 93.12 94.42 94.96 75.0 79.32 83.65 85.80 87.04 90.79 92.87 94.25 95.37 95.85 77.5 82.59 86.30 88.06 89.20 92.39 94.27 95.26 96.21 96.62 80.0 85.56 88.79 90.18 91.12 93.55 95.33 96.13 96.91 97.28 82.5 88.21 90.94 91.96 92.73 94.57 96.22 96.91 97.52 97.83 85.0 90.54 92.81 93.58 94.21 95.63 96.99 97.57 98.02 98.28 87.5 92.38 94.33 94.92 95.43 96.54 97.63 98.13 98.47 98.67 90.0 94.07 95.68 96.21 96.58 97.41 98.22 98.62 98.87 99.02 92.5 95.63 96.87 97.33 97.65 98.29 98.77 99.06 99.21 99.31 95.0 97.26 98.08 98.49 98.77 99.23 99.30 99.44 99.52 99.59 97.5 98.85 99.25 99.34 99.44 99.54 99.63 99.72 99.82 99.86 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 6 to 12 hours

2.5 0.05 0.19 0.52 0.69 1.18 1.48 1.64 2.98 4.45 5.0 .76 1.69 2.18 2.78 3.71 4.51 5.30 8.25 9.93 7.5 1.55 3.14 3.82 4.79 6.28 7.44 8.84 13.56 15.35 

10.0 2.32 4.68 5.56 6.79 8.98 10.46 12.45 18.83 20.66 12.5 3.10 6.20 7.38 8.75 11.69 13.55 15.97 23.65 25.56 15.0 3.98 7.84 9.22 10.65 14.38 16.60 19.44 27.82 29.64 17.5 4.95 9.50 11.09 12.66 16.98 19.57 22.78 31.00 32.89 20.0 6.00 11.23 13.03 14.87 19.50 22.57 26.09 33.61 36.07 22.5 7.20 12.76 14.85 17.01 21.98 25.45 29.21 35.98 39.43 25.0 8.46 14.34 16.75 19.28 24.57 28.35 32.28 38.96 43.31 27.5 9.87 15.65 18.52 21.47 27.24 31.21 35.23 42.19 47.58 30.0 11.82 17.32 20.45 23.61 29.82 34.02 38.08 45.92 52.20 32.5 14.11 19.58 23.02 26.25 32.93 37.21 41.35 49.95 56.29 35.0 16.91 22.59 26.27 29.50 36.30 40.70 44.85 54.05 59.94 37.5 20.13 26.13 29.87 33.30 40.30 44.52 48.71 57.76 63.09 40.0 23.61 30.45 34.17 38.18 44.89 48.93 53.12 61.65 66.36 42.5 26.38 34.82 38.72 43.38 49.71 53.50 57.67 65.33 69.39 45.0 29.35 38.97 43.02 48.08 54.16 57.84 61.75 68.92 72.61 47.5 31.96 42.78 47.05 52.37 58.43 61.98 65.64 72.22 75.48 50.0 35.02 46.51 50.90 56.07 61.87 65.55 68.94 75.24 78.13 52.5 38.63 50.10 54.60 58.89 64.83 68.56 71.78 77.94 80.42 55.0 43.55 53.89 58.25 61.72 67.71 71.63 74.77 80.73 82.74 57.5 48.65 57.98 61.88 64.70 70.53 74.69 77.79 83.23 84.85 60.0 54.15 62.35 65.58 67.81 73.35 77.64 80.76 85.69 87.12 62.5 59.22 66.76 69.42 71.27 76.32 80.90 83.94 88.14 89.34 65.0 63.39 70.90 72.93 74.69 78.97 83.86 86.76 90.35 91.38 67.5 66.30 74.38 76.10 77.68 81.53 86.39 89.00 92.11 93.07 70.0 68.60 77.05 78.73 80.21 83.86 88.47 90.83 93.62 94.51 72.5 70.65 79.18 80.89 82.33 85.94 90.26 92.30 94.82 95.65 75.0 72.42 80.79 82.56 83.98 87.71 91.59 93.37 95.72 96.54 77.5 74.50 82.29 84.16 85.53 89.42 92.84 94.37 96.41 97.26 80.0 76.94 83.96 85.71 87.04 90.91 93.92 95.32 97.02 97.84 82.5 79.67 85.93 87.48 88.71 92.26 94.98 96.24 97.60 98.35 85.0 82.51 87.94 89.28 90.44 93.47 95.92 97.08 98.13 98.75 87.5 85.54 90.09 91.17 92.22 94.74 96.77 97.79 98.59 99.12 90.0 88.58 92.27 93.11 94.01 95.98 97.57 98.38 99.01 99.40 92.5 91.73 94.48 95.14 95.83 97.19 98.36 98.92 99.36 99.64 95.0 94.87 96.71 97.18 97.67 98.46 99.16 99.41 99.64 99.82 97.5 97.86 98.96 99.29 99.51 99.78 99.84 99.90 99.95 99.99 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 12 to 24 hours 2.5 0.88 1.14 1.28 1.36 1.44 1.53 3.15 5.01 6.28 

5.0 1.71 2.72 3.11 3.51 3.80 4.99 7.51 10.70 12.60 7.5 2.50 4.26 4.93 5.64 6.29 8.42 11.78 16.39 18.83 

10.0 3.32 5.85 6.82 7.84 9.37 11.88 16.04 21.96 24.89 12.5 4.05 7.36 8.62 10.02 12.40 15.31 20.22 27.30 30.46 15.0 4.70 8.85 10.47 12.22 15.37 18.68 24.16 31.95 35.03 17.5 5.25 10.33 12.29 14.42 18.23 22.00 27.86 35.76 38.68 20.0 5.82 11.87 14.17 16.68 21.09 25.35 31.56 38.98 41.66 22.5 6.34 13.40 16.05 18.91 23.85 28.63 34.92 41.82 44.19 25.0 7.01 15.05 18.08 21.21 26.52 31.82 38.02 44.49 46.65 27.5 7.90 16.80 20.09 23.53 29.26 35.04 41.20 47.51 49.96 30.0 9.16 18.70 22.22 25.91 32.10 38.43 44.58 50.85 53.66 32.5 10.92 20.81 24.45 28.34 34.96 41.81 47.84 54.52 57.80 35.0 13.37 23.19 26.86 30.96 38.12 45.36 51.29 58.47 62.43 37.5 16.56 25.93 29.67 33.89 41.58 49.13 55.04 62.51 67.02 40.0 20.51 29.39 33.11 37.39 45.25 52.99 58.88 66.47 70.83 42.5 25.13 33.72 37.45 41.65 49.53 56.87 62.49 70.38 74.33 45.0 30.05 38.55 42.26 46.45 54.23 60.97 66.19 73.98 77.34 47.5 34.85 43.59 47.15 51.26 58.84 64.86 69.87 77.22 79.81 50.0 39.56 48.82 52.11 56.13 63.46 68.71 73.36 80.21 82.20 52.5 43.71 53.41 56.70 60.51 67.66 72.28 76.46 82.91 84.71 55.0 47.28 57.29 60.66 64.23 71.05 75.46 79.46 85.30 87.13 57.5 50.34 60.47 64.13 67.29 73.82 78.13 82.02 87.37 89.31 60.0 53.19 63.27 67.47 70.17 76.30 80.62 84.30 89.26 91.29 62.5 55.23 65.60 70.12 72.44 78.07 82.38 86.02 90.64 92.76 65.0 57.33 67.93 72.57 74.64 79.72 83.90 87.52 91.71 93.84 67.5 59.18 69.98 74.61 76.48 81.13 85.04 88.63 92.43 94.48 70.0 61.12 72.19 76.55 78.29 82.50 86.06 89.59 93.07 95.07 72.5 63.07 74.40 78.20 79.92 83.71 86.88 90.27 93.52 95.47 75.0 65.81 76.63 80.09 81.76 85.33 88.13 91.17 94.17 95.94 77.5 68.82 78.86 81.92 83.51 87.03 89.47 92.12 94.84 96.39 80.0 72.23 81.21 83.91 85.46 88.94 91.15 93.29 95.64 96.94 82.5 75.74 83.50 85.96 87.44 90.83 92.85 94.49 96.43 97.42 85.0 78.99 85.82 88.13 89.48 92.74 94.53 95.74 97.24 97.95 87.5 81.99 88.14 90.33 91.51 94.46 95.95 96.86 97.95 98.43 90.0 84.68 90.45 92.53 93.53 96.00 97.18 97.82 98.55 98.88 92.5 87.48 92.76 94.70 95.50 97.30 98.13 98.57 99.04 99.25 95.0 90.46 95.09 96.87 97.46 98.44 98.93 99.19 99.45 99.58 97.5 93.86 97.43 99.05 99.26 99.48 99.63 99.72 99.80 99.85 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 24 to 72 hours

2.5 0.58 1.00 1.63 2.06 3.56 5.17 8.55 10.80 13.21 5.0 1.00 2.25 3.46 4.36 7.15 12.94 21.47 25.29 28.20 7.5 1.39 3.32 4.91 6.21 10.02 19.01 31.96 38.31 41.91 

10.0 1.77 4.20 6.00 7.52 11.92 23.19 39.23 48.90 53.16 12.5 2.10 4.81 6.61 8.18 12.72 24.49 41.80 55.21 60.36 15.0 2.44 5.37 6.97 8.61 13.36 24.70 42.80 57.80 64.26 17.5 2.77 5.87 7.21 8.82 13.98 24.90 43.20 58.20 65.16 20.0 3.21 6.57 7.80 9.48 15.37 25.20 43.50 58.30 65.40 22.5 3.71 7.29 8.47 10.27 16.93 25.70 43.70 58.40 65.60 25.0 4.36 8.21 9.43 11.44 19.24 27.20 44.00 58.50 65.80 27.5 5.17 9.25 10.66 12.81 21.36 29.32 44.40 58.60 66.00 30.0 6.31 10.57 12.16 14.56 23.69 32.28 44.70 58.70 66.20 32.5 7.82 12.24 13.85 16.29 25.34 35.01 45.40 58.80 66.40 35.0 9.92 14.74 16.46 18.96 27.88 38.03 46.50 59.00 66.60 37.5 12.86 18.31 20.16 22.71 30.94 41.06 48.26 59.20 66.80 40.0 16.79 22.99 25.04 27.70 35.03 44.37 51.47 60.30 67.00 42.5 21.57 28.78 31.06 33.68 39.72 47.93 54.74 62.35 68.20 45.0 27.00 35.19 37.80 40.47 45.42 51.93 58.41 65.53 70.01 47.5 33.09 41.67 44.44 47.06 51.11 56.22 62.21 69.08 73.00 50.0 39.16 47.69 50.67 53.15 56.70 60.84 66.52 72.96 76.23 52.5 44.85 53.16 56.18 58.47 62.07 65.63 70.89 76.76 79.41 55.0 50.14 57.75 60.82 63.07 67.19 70.62 75.50 80.64 82.80 57.5 54.87 61.90 65.01 67.27 72.13 75.55 79.99 84.46 86.22 60.0 58.42 65.70 69.04 71.42 76.84 80.21 84.32 88.10 89.56 62.5 60.61 68.94 72.38 74.82 80.76 84.16 87.96 91.31 92.49 65.0 61.79 71.39 75.02 77.87 83.90 87.36 90.85 93.80 94.79 67.5 62.00 72.93 77.03 80.20 86.20 89.68 92.89 95.53 96.32 70.0 62.50 73.23 77.92 81.44 87.25 91.00 94.06 96.58 97.20 72.5 63.00 73.70 78.00 81.49 87.30 91.48 94.51 96.98 97.53 75.0 63.50 74.00 78.25 81.70 87.50 91.61 94.61 97.02 97.61 77.5 64.00 74.50 78.50 81.90 87.70 91.80 94.80 97.03 97.65 80.0 64.50 75.00 78.75 82.10 87.90 92.00 95.00 97.05 97.69 82.5 65.80 75.50 79.00 82.30 88.10 92.20 95.20 97.08 97.79 85.0 67.77 76.00 79.40 82.50 88.30 92.40 95.40 97.26 97.97 87.5 70.42 76.89 80.00 83.20 88.50 92.60 95.60 97.54 98.21 90.0 73.67 80.13 82.50 85.09 89.20 92.93 95.94 97.89 98.49 92.5 78.19 84.25 86.26 88.39 91.19 94.34 96.73 98.32 98.81 95.0 84.02 88.96 90.59 92.21 93.96 96.16 97.56 98.75 99.13 97.5 90.76 94.20 95.32 96.27 96.89 98.17 98.43 99.19 99.45 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Second-quartile storms; storm duration 0 to 72 hours 2.5 0.12 0.68 0.87 1.05 1.99 2.81 5.01 5.58 7.40 

5.0 .89 2.10 2.56 3.01 4.41 5.89 8.79 13.14 16.42 7.5 1.63 3.45 4.19 4.91 6.78 8.89 12.58 20.02 24.47 

10.0 2.25 4.70 5.75 6.77 9.08 11.82 16.06 25.73 30.65 12.5 2.81 5.79 7.17 8.47 11.27 14.60 19.17 30.06 34.82 15.0 3.37 6.82 8.60 10.24 13.50 17.32 22.12 33.15 37.65 17.5 3.80 7.69 9.89 11.84 15.67 19.93 24.78 35.19 39.43 20.0 4.27 8.63 11.28 13.60 18.06 22.61 27.37 37.07 40.94 22.5 4.86 9.56 12.66 15.40 20.64 25.34 30.25 39.17 42.90 25.0 5.65 10.71 14.24 17.49 23.51 28.36 33.54 41.96 45.60 27.5 6.63 12.02 15.81 19.48 26.40 31.47 36.93 45.22 48.83 30.0 8.01 13.70 17.75 21.86 29.47 34.77 40.57 48.86 52.30 32.5 9.86 15.67 19.81 24.25 32.39 38.14 44.24 52.49 55.91 35.0 12.27 18.34 22.42 26.98 35.39 41.69 48.04 56.45 59.76 37.5 15.34 21.81 25.84 30.26 38.73 45.34 51.83 60.27 63.54 40.0 19.26 26.21 30.21 34.42 42.53 49.29 55.72 64.11 67.21 42.5 23.91 31.46 35.27 39.12 46.60 53.27 59.54 67.83 70.79 45.0 28.91 37.28 40.99 44.39 51.10 57.39 63.44 71.47 74.19 47.5 34.16 43.06 46.63 49.71 55.72 61.42 67.21 74.50 77.07 50.0 39.48 48.58 51.91 54.75 60.16 65.46 70.99 77.36 79.72 52.5 44.37 53.49 56.54 59.21 64.23 69.27 74.58 80.05 82.31 55.0 48.94 57.70 60.59 63.18 68.11 73.09 78.01 82.74 84.90 57.5 53.18 61.53 64.25 66.84 71.79 76.77 81.16 85.26 87.36 60.0 56.77 65.16 67.78 70.32 75.31 80.35 84.19 87.83 89.83 62.5 59.46 68.22 70.81 73.34 78.32 83.34 86.69 90.07 92.04 65.0 61.64 70.99 73.63 76.14 81.08 85.85 88.80 91.93 93.77 67.5 63.07 73.39 76.11 78.55 83.35 87.80 90.53 93.33 94.99 70.0 63.99 75.23 78.08 80.45 85.08 89.24 91.86 94.42 95.91 72.5 64.97 76.58 79.63 81.90 86.31 90.23 92.74 95.16 96.44 75.0 66.23 77.91 81.13 83.34 87.53 91.15 93.56 95.79 96.83 77.5 67.72 79.17 82.48 84.63 88.60 92.03 94.29 96.32 97.17 80.0 69.70 80.44 83.76 85.91 89.70 92.90 94.96 96.82 97.51 82.5 72.19 81.92 85.14 87.28 90.89 93.81 95.68 97.28 97.83 85.0 74.73 83.66 86.61 88.74 92.20 94.75 96.45 97.74 98.18 87.5 77.60 85.69 88.28 90.31 93.52 95.69 97.17 98.16 98.50 90.0 80.89 87.89 90.08 91.99 94.89 96.66 97.87 98.59 98.84 92.5 84.74 90.57 92.29 93.89 96.27 97.64 98.53 99.01 99.20 95.0 89.04 93.60 94.80 95.95 97.69 98.63 99.14 99.42 99.59 97.5 93.87 96.80 97.48 98.15 99.11 99.65 99.71 99.85 99.92 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 0 to 6 hours

2.5 0.36 0.55 0.61 0.90 1.36 1.83 2.67 4.23 4.50 5.0 .65 1.34 1.65 1.82 3.51 4.78 6.28 8.21 9.10 7.5 .97 2.08 2.61 3.25 5.64 7.58 9.65 11.87 13.20 

10.0 1.26 2.89 3.62 4.61 7.83 10.17 12.87 15.32 17.17 12.5 1.56 3.80 4.74 6.06 10.08 12.58 15.68 18.37 20.52 15.0 1.90 4.73 5.88 7.51 11.99 14.73 18.11 21.08 23.48 17.5 2.00 5.68 7.02 8.89 13.64 16.49 19.97 23.43 25.64 20.0 2.50 6.65 8.18 10.16 14.78 17.78 21.45 25.52 27.65 22.5 3.00 7.78 9.49 11.63 15.92 19.02 22.63 27.17 29.11 25.0 3.50 8.87 10.82 13.07 16.96 20.16 23.83 28.62 30.55 27.5 4.00 9.92 12.12 14.47 17.92 21.21 24.89 29.85 31.75 30.0 4.50 11.15 13.51 15.90 18.80 22.38 26.00 30.90 33.43 32.5 5.00 12.58 14.97 17.49 20.29 24.10 27.40 31.93 35.44 35.0 6.50 13.90 16.33 18.77 21.67 25.85 28.78 33.03 37.60 37.5 8.00 15.37 17.72 20.08 23.04 27.71 30.50 34.60 40.06 40.0 9.50 17.22 19.18 21.49 24.94 30.11 32.35 36.11 42.86 42.5 11.00 19.29 21.00 22.96 27.45 32.99 34.47 38.31 45.82 45.0 12.50 21.58 23.09 24.76 29.97 35.87 37.19 41.38 49.10 47.5 14.00 24.36 25.65 27.31 32.91 39.14 40.66 45.36 52.84 50.0 15.50 27.48 28.21 30.09 36.41 42.69 44.50 50.02 57.08 52.5 18.47 30.74 31.37 33.33 40.23 46.20 49.04 55.53 62.14 55.0 20.69 34.07 34.85 37.33 44.08 49.71 53.84 60.77 66.87 57.5 21.50 37.50 38.57 41.47 48.19 53.43 58.49 65.76 71.43 60.0 22.00 40.77 42.40 45.70 52.47 57.12 62.97 70.20 75.55 62.5 23.50 44.13 46.76 50.17 56.69 60.77 67.13 73.85 78.87 65.0 26.00 47.54 50.97 54.65 60.83 64.45 70.94 76.99 80.99 67.5 28.40 51.10 55.09 58.95 64.88 67.97 74.44 79.65 82.90 70.0 31.50 54.80 59.23 63.20 68.81 71.49 77.64 81.93 84.34 72.5 38.29 59.50 63.93 67.59 72.72 75.06 80.62 84.15 85.94 75.0 47.71 64.39 68.74 71.94 76.41 78.56 83.35 86.18 87.62 77.5 56.81 69.58 73.48 76.12 79.72 81.83 85.89 88.06 89.42 80.0 64.42 74.65 77.90 79.98 82.92 84.99 88.18 90.05 91.11 82.5 71.38 79.66 82.17 83.69 85.97 87.93 90.39 91.94 92.86 85.0 76.98 83.59 85.54 86.79 88.57 90.47 92.39 93.64 94.38 87.5 82.01 87.19 88.56 89.66 91.04 92.80 94.22 95.20 95.77 90.0 86.26 90.32 91.37 92.28 93.37 94.86 95.82 96.54 96.98 92.5 90.47 93.30 94.07 94.72 95.50 96.61 97.28 97.76 98.04 95.0 94.53 96.09 96.62 96.96 97.48 98.10 98.49 98.79 98.94 97.5 98.54 98.97 99.10 99.20 99.35 99.46 99.51 99.63 99.71 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 6 to 12 hours 2.5 0.43 0.69 0.75 0.83 1.42 2.32 2.76 3.23 4.17 

5.0 .78 1.74 1.96 2.30 3.20 4.35 5.14 6.99 8.01 7.5 1.13 2.69 3.22 3.79 4.93 6.32 7.41 10.42 11.65 

10.0 1.48 3.57 4.46 5.23 6.72 8.35 9.82 13.56 15.33 12.5 1.82 4.42 5.70 6.64 8.45 10.29 12.04 16.24 18.76 15.0 2.17 5.15 6.85 7.93 10.02 12.17 14.46 18.95 22.14 17.5 2.52 5.74 7.89 9.09 11.39 13.85 16.83 21.42 25.21 20.0 2.87 6.31 8.83 10.05 12.62 15.52 19.58 24.04 28.33 22.5 3.21 6.91 9.71 10.94 13.55 16.91 22.31 26.40 30.86 25.0 3.59 7.52 10.47 11.70 14.36 18.26 25.45 28.79 33.16 27.5 3.95 8.11 11.12 12.32 15.12 19.32 27.58 30.80 34.98 30.0 4.32 8.65 11.58 12.74 15.72 20.16 29.19 32.46 36.58 32.5 4.68 9.14 12.01 13.18 16.30 20.84 29.94 33.67 37.48 35.0 5.00 9.56 12.19 13.41 16.98 21.44 30.05 34.48 38.11 37.5 5.25 9.99 12.30 13.65 17.80 21.87 30.20 34.69 38.71 40.0 5.62 10.62 12.52 13.96 18.81 22.50 30.50 34.72 39.33 42.5 5.92 11.37 13.05 14.69 20.10 23.54 30.80 34.83 39.90 45.0 6.32 12.23 13.93 15.83 21.62 24.70 31.00 35.38 41.05 47.5 6.88 13.50 15.35 17.64 23.47 26.55 31.60 36.80 42.88 50.0 7.73 14.97 17.18 19.81 25.60 28.98 34.00 39.25 45.19 52.5 8.76 16.74 19.50 22.64 28.09 31.93 36.89 42.64 48.00 55.0 10.27 19.06 22.25 25.67 31.10 35.49 40.51 46.76 51.58 57.5 11.99 21.80 25.36 28.73 34.47 39.64 44.47 51.19 55.66 60.0 14.23 24.82 28.61 31.98 38.29 44.05 48.87 55.78 60.01 62.5 16.41 28.33 32.24 35.84 42.57 48.82 53.62 60.62 64.61 65.0 18.33 32.24 36.23 39.92 47.24 53.90 58.72 65.47 69.40 67.5 21.02 36.62 40.66 44.60 52.24 58.86 63.83 70.30 73.93 70.0 25.01 41.74 45.61 50.04 57.78 64.01 69.02 75.19 78.26 72.5 29.81 47.50 51.22 56.02 63.48 69.29 74.22 79.88 82.33 75.0 36.13 53.87 57.39 62.14 69.36 74.50 78.97 83.94 85.85 77.5 44.42 60.85 64.04 68.48 75.06 79.37 83.15 87.41 88.88 80.0 52.99 67.87 70.72 74.60 80.39 83.94 86.82 90.22 91.39 82.5 61.18 74.47 76.95 80.14 85.00 87.88 89.93 92.48 93.37 85.0 69.06 80.37 82.53 84.89 88.90 91.06 92.36 94.20 94.93 87.5 76.42 85.48 87.24 88.89 91.97 93.55 94.37 95.65 96.21 90.0 82.61 89.55 90.92 92.07 94.37 95.50 96.02 96.86 97.26 92.5 88.00 92.83 93.82 94.63 96.25 97.02 97.39 97.90 98.16 95.0 92.75 95.65 96.28 96.78 97.81 98.27 98.50 98.76 98.92 97.5 97.09 98.28 98.52 98.73 99.22 99.36 99.47 99.55 99.63 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 12 to 24 hours

2.5 0.25 0.58 0.83 1.11 1.60 1.53 2.77 3.12 3.34 5.0 .78 1.47 1.89 2.32 2.93 3.55 4.81 5.86 6.93 7.5 1.21 2.33 2.93 3.52 4.28 5.41 6.83 8.50 10.20 

10.0 1.51 3.07 3.98 4.70 5.66 7.08 8.91 11.03 13.28 12.5 1.68 3.75 4.97 5.81 7.06 8.68 10.94 13.42 16.02 15.0 1.70 4.30 5.73 6.68 8.42 10.20 12.74 15.73 18.09 17.5 1.60 4.74 6.29 7.41 9.69 11.59 14.40 17.78 19.81 20.0 1.51 5.00 6.64 7.92 10.87 13.09 15.89 19.44 21.20 22.5 1.46 5.25 6.85 8.23 11.89 14.59 17.18 20.88 22.28 25.0 1.43 5.31 6.84 8.32 12.52 15.65 18.18 22.12 23.24 27.5 1.49 5.41 6.90 8.44 12.85 16.46 19.12 23.08 24.22 30.0 1.65 5.42 6.81 8.27 12.75 16.91 19.69 23.92 25.05 32.5 1.79 5.51 6.82 8.19 12.33 16.78 20.00 24.69 25.88 35.0 2.00 5.55 6.78 8.13 11.94 16.59 20.10 25.44 26.77 37.5 2.27 5.76 6.94 8.29 11.76 16.72 20.27 26.03 27.62 40.0 2.53 5.95 7.10 8.49 11.86 16.79 20.29 26.66 28.55 42.5 3.01 6.52 7.78 9.41 12.71 17.31 20.84 27.48 29.73 45.0 3.89 7.40 8.69 10.64 14.11 18.80 22.25 29.00 31.43 47.5 5.12 8.88 10.25 12.60 16.16 21.00 24.61 31.20 33.88 50.0 6.70 10.91 12.38 15.23 19.16 24.08 28.15 34.80 37.70 52.5 9.09 13.96 15.64 18.99 23.24 28.57 33.21 39.45 42.51 55.0 11.99 17.73 19.57 23.26 28.11 34.04 39.22 45.14 48.39 57.5 15.09 22.04 24.45 28.38 34.01 40.12 45.73 51.44 55.01 60.0 18.64 26.63 29.59 33.67 40.36 46.59 52.38 58.01 61.82 62.5 22.51 31.64 35.08 39.14 46.60 53.01 58.84 64.08 67.96 65.0 26.34 36.52 40.19 44.23 52.30 58.92 64.74 69.77 73.60 67.5 30.13 41.49 45.26 49.21 57.34 64.10 69.91 74.65 78.27 70.0 34.52 46.41 49.87 53.86 61.73 68.66 74.36 78.65 81.84 72.5 39.22 51.39 55.00 58.72 65.84 72.71 78.29 81.92 84.58 75.0 44.56 56.23 60.07 63.56 69.95 76.38 81.57 84.64 86.80 77.5 50.26 61.09 65.29 68.49 74.18 79.74 84.28 86.78 88.54 80.0 56.56 65.84 70.23 73.18 78.37 82.99 86.71 88.75 90.15 82.5 62.67 70.67 75.12 77.65 82.26 85.89 88.96 90.70 91.87 85.0 68.55 75.34 79.26 81.57 85.66 88.46 90.92 92.52 93.55 87.5 73.97 79.94 83.14 85.19 88.63 90.76 92.77 94.24 95.14 90.0 79.18 84.37 86.75 88.44 91.18 92.85 94.57 95.86 96.56 92.5 84.00 88.58 90.33 91.63 93.59 94.79 96.18 97.24 97.77 95.0 88.73 92.69 93.90 94.84 95.96 96.73 97.65 98.38 98.72 97.5 93.48 96.85 97.54 98.05 98.37 98.67 99.06 99.40 99.53 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 24 to 72 hours 2.5 0.54 1.16 1.47 1.73 2.00 2.55 3.48 4.57 5.16 

5.0 1.43 2.70 3.08 3.53 4.63 5.22 6.86 8.55 9.24 7.5 2.18 4.05 4.54 5.25 7.12 7.72 10.07 12.34 13.15 

10.0 2.80 5.27 5.92 6.87 9.29 9.87 13.01 15.88 16.99 12.5 3.35 6.37 7.19 8.32 11.04 11.65 15.53 18.91 20.44 15.0 3.77 7.33 8.35 9.70 12.45 13.30 17.74 21.46 23.48 17.5 4.09 8.11 9.31 10.85 13.66 14.75 19.72 23.62 25.98 20.0 4.46 8.85 10.21 11.82 14.79 16.15 21.45 25.44 28.00 22.5 4.87 9.50 10.96 12.63 15.85 17.66 23.05 27.01 29.39 25.0 5.24 10.01 11.58 13.32 16.97 19.30 24.62 28.54 30.62 27.5 5.64 10.43 12.12 13.87 18.22 20.99 26.08 30.02 31.77 30.0 6.05 10.85 12.61 14.35 19.39 22.66 27.52 31.43 33.06 32.5 6.44 11.21 13.06 14.75 20.33 24.18 28.80 32.79 34.53 35.0 6.68 11.47 13.39 15.01 21.02 25.44 29.90 33.95 36.04 37.5 6.92 11.76 13.67 15.24 21.25 26.17 30.77 35.06 37.34 40.0 7.09 12.08 13.96 15.49 21.40 26.27 31.23 35.85 38.27 42.5 7.33 12.56 14.46 15.99 21.60 26.48 31.51 36.48 38.90 45.0 7.83 13.78 15.60 17.29 22.20 27.22 32.37 37.51 39.75 47.5 8.83 16.11 18.05 19.90 23.85 28.91 34.20 39.64 41.83 50.0 10.21 19.43 21.67 23.66 27.05 32.02 37.16 42.78 45.29 52.5 11.95 23.09 25.61 28.21 31.38 36.70 41.65 47.33 50.15 55.0 13.91 26.55 29.62 32.87 36.16 41.68 46.96 52.81 55.98 57.5 15.82 29.36 33.40 37.02 40.93 46.78 52.36 58.47 62.11 60.0 17.65 31.22 36.29 40.29 45.33 51.26 57.17 63.45 67.44 62.5 19.28 32.59 38.53 43.19 49.39 55.42 61.68 68.02 71.93 65.0 20.93 34.27 40.84 45.74 52.92 59.04 65.59 71.97 75.71 67.5 22.55 37.11 43.78 48.85 56.44 63.14 69.43 75.75 79.27 70.0 24.12 39.98 46.64 52.00 59.83 66.73 72.98 79.22 82.46 72.5 25.88 43.17 49.73 55.19 63.25 70.44 76.48 82.49 85.29 75.0 27.80 46.34 52.75 57.89 66.61 73.64 79.40 85.13 87.72 77.5 30.19 49.79 56.12 60.81 70.10 76.65 82.04 87.47 89.84 80.0 33.27 52.83 59.32 63.49 73.45 79.00 84.18 89.24 91.39 82.5 38.07 57.19 63.39 67.16 76.94 81.68 86.29 90.78 92.65 85.0 44.29 62.24 67.94 71.47 80.34 84.23 88.37 92.31 93.99 87.5 52.29 68.24 73.24 76.55 83.81 86.93 90.55 93.93 95.32 90.0 61.48 74.67 78.89 81.79 87.38 89.67 92.66 95.39 96.50 92.5 71.68 81.68 84.95 87.31 91.02 92.62 94.82 96.78 97.57 95.0 81.65 88.52 90.83 92.59 94.68 95.58 96.95 98.10 98.57 97.5 91.69 95.59 96.83 97.80 98.34 98.66 99.05 99.34 99.47 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Third-quartile storms; storm duration 0 to 72 hours

2.5 0.45 0.89 1.04 1.35 1.95 2.51 2.73 3.68 4.35 5.0 .96 2.11 2.42 2.92 3.87 4.73 6.02 7.58 8.49 7.5 1.42 3.22 3.70 4.48 5.72 6.86 9.05 11.28 12.41 

10.0 1.81 4.24 4.89 6.03 7.57 8.96 11.78 14.68 16.17 12.5 2.21 5.23 6.04 7.48 9.29 10.92 14.10 17.53 19.38 15.0 2.59 6.08 7.09 8.77 10.86 12.76 16.08 19.97 22.23 17.5 2.91 6.77 8.00 9.90 12.23 14.41 17.79 22.09 24.60 20.0 3.22 7.36 8.81 10.82 13.44 15.95 19.42 23.92 26.65 22.5 3.56 7.91 9.55 11.56 14.48 17.34 20.92 25.50 28.16 25.0 3.80 8.26 10.11 12.12 15.36 18.66 22.47 27.12 29.72 27.5 4.08 8.60 10.60 12.63 16.20 19.91 23.99 28.66 31.07 30.0 4.32 8.87 11.01 12.99 16.87 21.05 25.42 30.05 32.38 32.5 4.61 9.19 11.40 13.30 17.42 22.08 26.66 31.27 33.61 35.0 4.82 9.43 11.67 13.52 17.85 22.89 27.77 32.33 34.84 37.5 5.12 9.77 11.95 13.77 18.25 23.45 28.57 33.15 35.82 40.0 5.39 10.08 12.23 14.07 18.53 23.77 29.16 33.80 36.67 42.5 5.84 10.76 12.79 14.64 19.08 24.24 29.81 34.44 37.43 45.0 6.48 11.69 13.81 15.78 20.20 25.14 30.91 35.58 38.65 47.5 7.51 13.41 15.66 17.88 22.26 27.11 32.80 37.64 40.73 50.0 8.84 15.60 18.24 20.87 25.31 30.15 35.79 40.81 43.90 52.5 10.53 18.38 21.56 24.66 29.40 34.37 39.86 45.08 48.21 55.0 12.45 21.32 25.17 28.80 33.99 39.28 44.68 50.19 53.50 57.5 14.51 24.65 28.99 33.03 38.71 44.53 49.78 55.65 59.08 60.0 16.71 27.86 32.65 37.04 43.31 49.48 54.82 60.88 64.42 62.5 19.05 31.39 36.44 40.92 47.76 54.35 59.79 65.76 69.36 65.0 21.52 35.03 40.19 44.63 51.95 58.90 64.48 70.24 73.76 67.5 24.30 39.09 44.34 48.71 56.30 63.36 68.96 74.46 77.72 70.0 27.37 43.30 48.61 52.94 60.73 67.56 73.24 78.29 81.19 72.5 30.78 47.90 53.17 57.40 65.13 71.75 77.26 81.74 84.27 75.0 34.87 52.56 57.68 61.91 69.36 75.58 80.70 84.72 86.86 77.5 39.77 57.47 62.36 66.49 73.54 79.15 83.79 87.32 89.14 80.0 45.21 62.39 66.89 70.87 77.36 82.29 86.47 89.43 90.99 82.5 51.52 67.46 71.50 75.22 80.97 85.28 88.87 91.31 92.67 85.0 58.42 72.46 75.96 79.31 84.32 87.93 91.04 93.08 94.19 87.5 65.64 77.59 80.38 83.26 87.48 90.36 93.09 94.73 95.61 90.0 72.88 82.58 84.68 87.09 90.36 92.62 94.88 96.17 96.81 92.5 80.35 87.50 88.96 90.82 93.17 94.86 96.48 97.44 97.86 95.0 87.52 92.28 93.17 94.46 95.93 97.15 97.91 98.51 98.75 97.5 94.68 96.96 97.40 98.10 98.68 98.94 99.21 99.44 99.53 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 0 to 6 hours 2.5 -- 0.12 0.27 0.40 0.67 1.00 1.56 2.30 3.21 

5.0 -- .20 .50 .60 1.18 2.25 3.81 5.50 6.70 7.5 -- .30 .80 .90 1.70 3.40 5.90 8.70 10.10 

10.0 -- .38 1.11 1.20 2.19 4.50 7.90 11.88 13.56 12.5 -- .50 1.30 1.40 2.68 5.32 9.57 14.40 16.40 15.0 -- .60 1.47 1.67 3.20 6.33 11.48 16.90 19.30 17.5 -- .80 1.65 1.81 3.69 6.97 12.90 19.17 21.88 20.0 -- .90 1.66 1.84 4.16 7.74 14.16 20.20 23.40 22.5 -- 1.04 1.67 1.86 4.33 8.07 14.93 21.17 24.60 25.0 -- 1.17 1.68 1.89 4.48 8.58 15.59 21.24 25.02 27.5 -- 1.40 1.83 1.99 4.64 8.78 15.79 21.75 25.53 30.0 -- 1.70 2.10 2.30 4.77 9.48 15.81 21.80 25.70 32.5 -- 1.99 2.36 2.58 4.92 9.79 15.95 21.83 25.80 35.0 -- 2.30 2.75 3.10 5.40 10.80 16.10 22.30 25.90 37.5 -- 2.58 3.14 3.63 5.93 11.80 16.25 22.73 26.00 40.0 -- 3.00 3.73 4.30 6.84 12.72 16.81 23.29 26.20 42.5 -- 3.30 4.40 5.20 7.80 13.80 17.50 24.10 26.40 45.0 -- 3.71 5.09 6.01 8.67 14.86 18.10 24.99 26.80 47.5 -- 4.00 5.80 7.00 10.00 16.05 19.30 26.00 27.20 50.0 -- 4.30 6.58 7.98 11.25 17.60 20.51 27.11 27.82 52.5 -- 4.63 7.49 9.13 12.59 19.22 22.26 28.32 29.22 55.0 -- 5.86 8.43 10.37 14.46 21.05 24.51 29.77 30.92 57.5 -- 7.00 10.05 12.39 16.87 22.93 27.01 31.73 33.13 60.0 -- 8.08 11.85 14.54 19.41 25.36 30.49 34.54 36.09 62.5 -- 10.19 14.20 17.34 22.50 28.18 34.45 37.55 39.16 65.0 -- 12.75 17.43 20.94 26.13 31.47 38.85 41.88 43.71 67.5 -- 16.50 21.22 25.07 30.42 35.53 43.67 47.38 49.37 70.0 -- 19.94 25.00 29.18 34.66 40.44 49.45 53.99 56.27 72.5 -- 23.75 29.09 33.60 39.65 45.40 54.93 61.03 63.79 75.0 -- 27.56 33.17 37.92 45.01 50.53 60.50 69.32 72.36 77.5 -- 31.34 36.99 42.12 50.69 56.22 66.33 76.70 79.66 80.0 -- 35.41 41.12 46.31 56.24 62.12 72.16 82.57 85.38 82.5 -- 40.13 45.62 50.75 62.18 67.98 77.48 87.11 89.60 85.0 -- 45.92 51.18 56.23 68.36 73.90 82.50 90.72 92.60 87.5 -- 53.27 57.96 62.72 74.39 79.61 87.06 92.71 94.00 90.0 -- 61.92 65.90 70.11 80.71 85.00 90.88 94.32 95.23 92.5 -- 71.85 74.80 78.29 86.71 89.90 93.94 95.97 96.48 95.0 -- 82.68 84.47 86.87 92.28 94.26 96.51 97.83 98.06 97.5 -- 93.88 94.36 95.39 97.57 98.57 98.84 99.60 99.80 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 6 to 12 hours

2.5 0.32 0.97 1.23 1.73 3.32 4.22 4.88 7.54 8.27 5.0 1.36 2.49 2.86 3.73 6.07 8.37 10.72 13.59 14.33 7.5 2.41 3.99 4.49 5.74 8.81 12.51 16.04 18.71 19.46 

10.0 3.55 5.66 6.26 7.96 11.60 16.42 20.27 22.76 23.57 12.5 4.69 7.30 8.08 10.23 14.27 19.99 23.56 25.90 26.87 15.0 5.90 8.96 10.04 12.59 16.96 23.02 26.35 28.57 29.65 17.5 6.81 10.72 12.06 14.93 19.22 25.38 28.36 30.47 31.80 20.0 8.03 12.74 14.33 17.35 21.58 27.19 30.11 32.56 34.11 22.5 8.83 14.30 16.15 19.23 23.76 28.71 31.79 34.65 36.44 25.0 9.70 16.00 18.01 21.03 25.94 29.97 33.23 36.50 38.43 27.5 10.21 17.44 19.72 22.64 27.38 30.95 34.34 37.96 40.08 30.0 10.76 18.58 21.11 23.84 28.57 31.67 35.25 39.33 41.51 32.5 10.81 19.22 22.05 24.56 28.70 32.15 35.69 40.26 42.58 35.0 10.86 19.84 23.01 25.22 28.80 32.63 36.19 40.95 43.19 37.5 11.10 19.97 23.37 25.40 28.96 32.87 36.46 41.20 43.39 40.0 11.40 20.10 23.50 25.60 29.14 32.98 36.65 41.29 43.42 42.5 11.70 20.20 23.60 25.90 29.30 33.00 36.68 41.33 43.50 45.0 12.00 20.30 23.80 26.20 29.50 33.06 36.81 41.37 43.65 47.5 12.20 20.40 23.90 26.40 29.70 33.09 36.87 41.41 43.75 50.0 12.50 20.45 24.10 26.70 29.80 33.11 36.93 41.45 43.90 52.5 12.80 20.50 24.20 26.90 30.00 33.14 37.00 41.49 44.00 55.0 13.10 20.60 24.40 27.20 30.20 33.16 37.06 41.53 44.11 57.5 13.30 20.70 24.50 27.50 30.40 33.19 37.12 42.36 45.07 60.0 13.60 20.80 24.60 27.70 30.60 33.77 37.70 43.68 46.51 62.5 13.90 20.90 24.80 28.00 30.80 34.74 38.24 44.97 47.61 65.0 14.20 21.00 24.90 28.20 31.00 36.03 40.12 46.65 49.04 67.5 14.40 21.10 25.00 28.50 31.10 37.75 42.13 48.29 50.41 70.0 14.70 21.50 25.60 28.80 32.00 40.12 44.51 50.43 52.28 72.5 15.00 23.00 27.00 30.20 34.63 43.06 47.08 52.77 54.33 75.0 17.00 26.57 30.71 33.81 39.28 46.85 50.66 55.79 57.19 77.5 20.71 32.59 36.59 38.86 44.73 51.34 54.71 59.46 60.80 80.0 25.99 38.27 41.98 43.63 50.79 56.94 60.15 64.57 65.91 82.5 30.00 43.65 47.28 48.72 57.41 63.50 66.62 70.45 71.81 85.0 32.93 48.24 51.93 53.94 63.96 70.59 73.83 76.85 78.15 87.5 36.02 53.43 57.29 59.85 70.18 77.51 80.50 82.99 84.22 90.0 40.40 59.35 63.67 66.65 76.36 83.91 86.66 88.58 89.61 92.5 47.96 67.31 71.55 74.45 82.60 89.44 91.59 92.97 93.74 95.0 58.93 77.23 80.75 82.69 88.56 94.13 95.48 96.26 96.70 97.5 72.71 88.61 91.05 91.25 94.51 98.14 98.57 98.87 99.05 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 12 to 24 hours 2.5 0.43 0.78 1.09 1.36 1.68 2.41 3.53 4.80 5.81 

5.0 .82 1.66 2.00 2.45 3.06 3.93 5.23 7.97 9.44 7.5 1.12 2.39 2.86 3.55 4.44 5.40 6.85 10.55 12.52 

10.0 1.40 3.09 3.62 4.58 5.67 6.63 8.31 12.74 14.95 12.5 1.51 3.66 4.31 5.43 6.69 7.73 9.60 14.38 16.60 15.0 1.74 4.24 5.16 6.29 7.70 8.88 10.89 15.85 17.80 17.5 1.90 4.83 6.16 7.40 9.04 10.24 12.31 17.16 19.01 20.0 2.24 5.49 7.19 8.62 10.48 11.87 13.96 18.84 20.54 22.5 2.42 6.10 8.36 9.96 12.16 13.95 15.94 20.58 22.39 25.0 2.79 6.89 9.82 11.70 14.24 16.38 18.36 22.79 24.93 27.5 3.06 7.67 11.15 13.38 16.40 18.96 20.92 25.08 27.81 30.0 3.59 8.40 12.33 14.86 18.28 21.52 23.60 27.55 30.62 32.5 4.06 9.15 13.56 16.24 20.01 23.89 26.18 30.07 33.35 35.0 4.81 10.09 14.69 17.49 21.53 26.11 28.73 32.62 35.86 37.5 5.57 10.93 15.60 18.49 22.82 27.95 31.07 35.02 37.92 40.0 6.57 11.91 16.55 19.60 23.98 29.68 33.33 37.24 39.76 42.5 7.39 13.11 17.56 20.76 25.23 31.09 35.31 39.23 41.34 45.0 8.41 14.47 18.65 22.04 26.59 32.56 37.21 41.06 42.74 47.5 9.58 15.80 19.77 23.28 28.03 33.86 38.84 42.70 44.10 50.0 10.88 17.18 20.87 24.72 29.40 35.70 40.38 44.03 45.35 52.5 12.18 18.50 21.90 26.32 30.82 37.48 41.70 45.24 46.53 55.0 13.40 19.61 22.83 27.65 32.11 39.08 42.80 46.22 47.65 57.5 14.26 20.34 23.51 28.52 33.27 40.26 43.53 46.96 48.69 60.0 14.69 20.77 23.94 29.03 34.22 41.09 44.01 47.51 49.46 62.5 15.10 21.15 24.30 29.19 34.97 41.25 44.20 47.90 50.20 65.0 15.27 21.41 24.66 29.50 35.54 41.40 44.28 48.21 50.66 67.5 16.11 22.18 25.48 29.80 36.54 41.56 44.68 48.83 51.45 70.0 17.01 23.43 26.76 30.17 37.83 42.46 45.86 50.07 52.68 72.5 17.74 24.89 28.45 32.13 39.66 43.96 47.77 52.06 54.78 75.0 18.14 26.30 30.21 34.15 41.76 45.74 50.14 54.77 57.59 77.5 19.00 28.09 32.41 36.88 44.25 47.99 53.11 58.19 61.38 80.0 19.70 30.03 34.83 39.90 47.26 51.22 56.79 62.33 65.69 82.5 21.04 32.68 37.88 43.94 51.32 55.38 61.06 66.98 70.56 85.0 23.90 36.24 42.05 48.54 56.47 60.72 66.09 72.07 75.65 87.5 28.97 42.12 48.52 55.43 63.41 67.67 72.35 77.77 80.93 90.0 36.35 50.03 56.64 63.75 71.70 75.58 79.26 83.59 85.99 92.5 46.69 59.80 66.18 72.87 80.06 83.13 85.80 88.95 90.66 95.0 59.84 71.14 76.88 82.17 88.08 90.18 91.83 93.78 94.79 97.5 74.82 83.94 88.39 92.06 95.90 96.81 97.45 98.20 98.48 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 24 to 72 hours

2.5 0.78 1.15 1.52 1.82 2.22 3.17 5.10 6.62 8.73 5.0 1.27 2.05 2.81 3.28 4.70 6.17 8.83 10.97 13.84 7.5 1.72 3.21 4.11 4.66 6.93 8.81 12.14 14.84 18.08 

10.0 2.08 4.31 5.26 6.02 8.77 10.95 14.82 17.97 21.04 12.5 2.31 5.17 6.17 7.19 10.20 12.72 16.86 20.30 22.84 15.0 2.78 5.90 6.99 8.17 11.34 14.33 18.73 22.37 24.46 17.5 3.49 6.61 7.84 9.04 12.09 15.67 20.18 24.31 25.88 20.0 4.39 7.49 8.74 9.95 12.92 17.08 21.72 26.29 27.60 22.5 5.51 8.58 9.92 11.02 13.94 18.60 23.21 28.28 29.81 25.0 6.82 10.14 11.56 12.48 15.23 20.17 24.74 30.45 32.36 27.5 8.08 12.07 13.51 14.32 16.87 21.72 26.18 32.22 34.18 30.0 9.16 14.16 15.65 16.46 18.88 23.33 27.78 33.70 35.78 32.5 10.14 16.39 17.90 18.80 20.97 24.93 29.26 34.98 37.14 35.0 11.01 18.24 19.69 20.72 22.92 26.53 30.85 36.14 38.22 37.5 11.84 19.56 21.03 22.25 24.69 28.02 32.40 37.04 38.94 40.0 12.55 20.63 22.13 23.51 26.34 29.50 33.90 38.15 40.04 42.5 13.25 21.43 22.93 24.46 27.65 30.98 35.40 39.38 41.19 45.0 14.02 21.99 23.51 25.19 28.86 32.46 36.90 40.71 42.43 47.5 14.94 22.73 24.28 26.14 30.16 33.97 38.34 42.08 43.69 50.0 15.74 23.61 25.16 27.17 31.47 35.52 39.80 43.56 45.08 52.5 16.71 24.63 26.16 28.36 32.75 37.06 41.34 45.12 46.54 55.0 17.64 25.93 27.41 29.71 34.23 38.58 42.91 46.67 48.00 57.5 18.44 27.13 28.53 30.96 35.60 39.99 44.38 48.01 49.27 60.0 19.23 28.29 29.75 32.23 36.80 41.35 45.79 49.35 50.62 62.5 20.27 29.64 31.11 33.54 37.96 42.63 47.16 50.57 51.92 65.0 21.12 30.82 32.31 34.77 39.26 43.74 48.45 51.64 53.10 67.5 22.04 31.88 33.47 36.01 40.48 44.88 49.57 52.81 54.30 70.0 23.00 33.10 34.90 37.48 41.92 46.42 50.77 54.24 55.67 72.5 24.36 34.39 36.45 39.18 43.65 48.23 52.42 55.98 57.30 75.0 25.99 36.07 38.39 41.28 45.82 50.48 54.62 58.32 59.60 77.5 28.16 38.07 40.88 43.95 48.40 53.51 57.45 61.38 62.59 80.0 30.76 40.54 43.86 47.02 51.43 57.00 61.01 65.01 66.22 82.5 34.32 43.66 47.48 50.56 54.98 61.01 65.31 69.23 70.54 85.0 38.25 47.76 51.90 54.77 59.27 65.52 69.96 73.68 75.14 87.5 43.39 52.67 57.26 59.99 64.39 70.54 74.84 78.30 79.75 90.0 50.42 59.36 63.71 66.05 70.21 75.83 79.90 83.01 84.39 92.5 59.53 67.57 71.44 73.39 77.12 81.36 85.06 87.76 89.02 95.0 70.28 77.14 80.26 81.90 84.91 86.75 90.09 92.43 93.45 97.5 82.61 87.72 89.83 91.12 93.27 94.18 95.08 97.15 97.86 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Fourth-quartile storms; storm duration 0 to 72 hours 2.5 0.43 0.97 1.30 1.75 2.57 3.28 4.00 5.78 7.25 

5.0 .92 1.92 2.52 3.04 4.27 5.16 7.60 10.25 12.19 7.5 1.37 2.85 3.68 4.34 5.95 7.53 10.73 14.20 16.41 

10.0 1.75 3.75 4.85 5.58 7.47 9.59 13.42 17.36 19.72 12.5 2.04 4.50 5.88 6.65 8.84 11.30 15.57 19.77 22.14 15.0 2.51 5.31 6.84 7.68 10.10 12.93 17.57 21.72 24.04 17.5 2.95 6.21 7.83 8.73 11.30 14.30 19.15 23.33 25.56 20.0 3.55 7.32 8.99 9.86 12.60 15.98 20.89 24.98 27.25 22.5 4.18 8.42 10.18 11.14 14.15 17.64 22.53 26.73 29.09 25.0 5.00 9.79 11.63 12.79 16.01 19.46 24.24 28.59 31.08 27.5 5.71 11.08 13.23 14.61 18.00 21.27 25.84 30.42 32.98 30.0 6.48 12.25 14.76 16.57 19.96 23.10 27.55 32.17 34.82 32.5 7.16 13.24 16.09 18.35 21.74 24.71 29.15 33.82 36.43 35.0 7.86 14.20 17.30 19.89 23.32 26.30 30.84 35.42 37.95 37.5 8.45 14.99 18.27 21.05 24.57 27.67 32.39 36.78 39.18 40.0 8.99 15.78 19.02 22.02 25.70 28.95 33.96 38.11 40.36 42.5 9.58 16.62 19.84 22.75 26.68 30.19 35.38 39.32 41.42 45.0 10.25 17.49 20.75 23.52 27.66 31.51 36.81 40.55 42.52 47.5 11.03 18.41 21.72 24.35 28.67 32.86 38.15 41.77 43.59 50.0 11.73 19.36 22.66 25.24 29.69 34.27 39.52 43.08 44.80 52.5 12.44 20.38 23.69 26.24 30.75 35.65 40.67 44.36 46.02 55.0 12.95 21.24 24.54 27.22 31.89 36.92 41.86 45.63 47.22 57.5 13.45 21.99 25.25 28.03 32.92 38.02 42.78 46.69 48.30 60.0 13.76 22.71 25.86 28.91 34.01 39.04 43.62 47.70 49.33 62.5 14.04 23.33 26.45 29.80 35.14 39.90 44.33 48.54 50.22 65.0 14.42 23.80 26.86 30.40 36.00 40.72 45.14 49.34 51.10 67.5 15.66 24.87 27.87 31.42 37.06 41.71 46.06 50.19 52.08 70.0 17.04 26.39 29.29 32.89 38.43 43.15 47.54 51.42 53.40 72.5 19.05 28.47 31.44 34.90 40.13 45.03 49.50 53.19 55.33 75.0 21.42 30.92 34.15 37.43 42.22 47.52 52.32 55.86 58.09 77.5 24.00 33.81 37.53 40.68 45.14 50.60 55.80 59.39 61.71 80.0 26.18 36.80 41.07 44.17 48.59 54.45 60.07 63.88 66.19 82.5 28.99 40.09 45.09 48.23 52.90 59.01 64.98 69.05 71.34 85.0 32.14 43.83 49.41 52.67 58.05 64.24 70.54 74.63 76.77 87.5 36.96 49.25 55.03 58.31 64.28 70.27 76.27 80.17 82.11 90.0 44.05 56.45 61.96 65.12 71.16 76.81 82.08 85.45 87.05 92.5 53.75 65.31 70.25 73.11 78.52 83.44 87.61 90.24 91.45 95.0 65.55 75.71 79.67 82.03 85.96 90.01 92.76 94.50 95.25 97.5 79.24 87.29 90.03 91.69 93.47 96.48 97.54 98.30 98.56 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 0 to 6 hours

2.5 0.55 1.12 1.40 1.71 3.35 4.00 5.95 7.61 8.94 5.0 1.41 3.37 3.96 5.06 7.82 9.96 12.91 16.01 17.93 7.5 2.40 5.67 6.84 8.33 12.14 15.88 19.74 24.33 26.82 

10.0 3.47 8.05 9.67 11.61 16.33 21.78 26.72 32.72 35.76 12.5 4.56 10.42 12.42 14.81 20.35 27.55 33.59 40.71 44.33 15.0 5.90 12.96 15.25 18.12 24.28 33.03 40.06 48.43 52.53 17.5 7.18 15.40 17.95 21.30 28.17 37.81 45.82 54.99 59.40 20.0 8.54 18.02 20.97 24.76 32.16 42.38 51.28 60.60 65.23 22.5 9.96 20.56 24.01 28.03 35.97 46.39 55.96 65.12 69.91 25.0 11.60 23.28 27.25 31.65 39.94 50.21 60.08 68.89 73.58 27.5 13.23 25.87 30.35 35.07 43.87 53.82 63.78 71.72 76.15 30.0 14.89 28.49 33.56 38.95 47.96 57.61 67.22 74.60 78.78 32.5 16.53 30.93 36.54 42.41 51.78 61.09 70.15 77.18 81.01 35.0 18.21 33.44 39.59 46.32 55.81 64.53 72.96 79.69 83.19 37.5 19.87 35.65 42.30 49.56 59.26 67.48 75.27 81.84 85.02 40.0 21.43 37.89 45.00 52.88 62.51 70.36 77.44 83.77 86.72 42.5 23.08 39.57 47.50 55.35 65.08 72.77 79.24 85.04 87.78 45.0 24.82 41.40 50.01 57.77 67.61 75.04 80.90 86.15 88.75 47.5 26.59 43.19 52.20 59.61 69.54 76.97 82.18 87.00 89.39 50.0 28.34 45.26 54.41 61.59 71.38 78.84 83.49 87.80 90.09 52.5 30.40 47.46 56.59 63.22 72.80 80.34 84.60 88.57 90.70 55.0 32.20 50.37 58.84 65.13 74.34 81.71 85.77 89.43 91.37 57.5 33.77 53.21 60.97 67.10 75.68 83.02 86.81 90.22 91.97 60.0 35.49 56.29 63.33 69.18 77.10 84.33 87.98 91.07 92.62 62.5 37.31 59.36 65.80 71.31 78.64 85.52 89.04 91.85 93.20 65.0 39.27 62.63 68.36 73.57 80.39 86.77 90.11 92.65 93.81 67.5 42.12 65.87 71.04 75.77 81.98 88.02 91.11 93.38 94.38 70.0 45.71 69.20 73.86 77.96 83.60 89.14 92.14 94.12 94.96 72.5 50.41 72.51 76.72 80.23 85.31 90.26 93.03 94.79 95.51 75.0 56.05 75.79 79.63 82.52 87.08 91.41 93.93 95.49 96.09 77.5 62.31 78.85 82.52 84.79 88.77 92.51 94.75 96.09 96.63 80.0 68.31 81.85 85.28 87.03 90.47 93.56 95.57 96.73 97.16 82.5 74.19 84.81 87.78 89.24 92.12 94.59 96.30 97.29 97.66 85.0 79.20 87.51 90.08 91.24 93.57 95.55 97.02 97.83 98.14 87.5 83.63 90.08 92.15 93.04 94.84 96.44 97.65 98.30 98.54 90.0 87.40 92.48 93.97 94.71 96.04 97.26 98.24 98.73 98.91 92.5 91.13 94.69 95.72 96.35 97.24 98.06 98.75 99.10 99.25 95.0 94.82 96.72 97.41 97.83 98.33 98.81 99.26 99.44 99.54 97.5 98.45 98.74 99.07 99.29 99.42 99.55 99.66 99.76 99.81 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 6 to 12 hours 2.5 0.73 1.65 2.17 2.90 4.57 6.09 6.84 8.99 10.42 

5.0 2.02 3.96 4.88 6.05 8.89 11.94 15.10 18.87 21.84 7.5 3.29 6.23 7.54 9.10 13.13 17.65 22.78 27.95 32.26 

10.0 4.56 8.47 10.23 12.20 17.41 23.14 29.42 36.02 41.36 12.5 5.83 10.53 12.69 15.17 21.31 27.96 34.78 42.65 48.64 15.0 7.05 12.55 15.24 18.05 25.00 32.25 39.64 48.40 54.71 17.5 8.20 14.28 17.69 20.71 28.10 35.83 43.58 53.02 59.30 20.0 9.34 16.01 20.24 23.32 31.05 38.87 47.16 57.29 63.25 22.5 10.39 17.55 22.78 25.67 33.77 41.52 50.71 60.88 66.49 25.0 11.43 19.26 25.54 28.07 36.64 44.11 54.46 64.36 69.57 27.5 12.39 20.79 27.63 30.02 39.10 46.47 57.77 67.56 72.28 30.0 13.31 22.33 29.38 31.86 41.41 48.66 60.63 70.40 74.81 32.5 14.09 23.54 30.65 33.43 43.39 50.73 63.18 72.66 76.95 35.0 14.74 24.77 31.56 34.90 45.16 52.75 65.36 74.67 78.77 37.5 15.16 25.72 31.98 35.97 46.52 54.67 67.03 76.22 80.23 40.0 15.69 26.69 32.71 37.23 48.09 56.58 68.59 77.37 81.30 42.5 16.04 27.47 33.31 38.31 49.62 58.42 70.17 78.34 82.12 45.0 16.45 28.50 34.15 39.58 51.11 60.34 71.56 79.27 82.80 47.5 16.98 29.41 35.10 40.80 52.49 62.23 72.90 80.15 83.43 50.0 17.82 30.57 36.54 42.38 54.10 64.11 74.23 81.04 84.01 52.5 18.76 31.82 38.02 43.93 55.40 66.01 75.40 81.93 84.73 55.0 20.02 33.47 39.83 45.76 57.11 67.90 76.57 82.85 85.47 57.5 21.39 35.20 41.68 47.61 59.02 69.76 77.78 83.82 86.26 60.0 22.99 37.35 43.80 49.80 61.20 71.62 78.93 84.80 87.10 62.5 24.63 39.68 45.92 51.92 63.45 73.53 80.12 85.79 88.01 65.0 26.20 42.29 48.31 54.38 66.10 75.41 81.35 86.82 88.88 67.5 27.79 44.82 50.69 57.03 68.63 77.33 82.65 87.86 89.78 70.0 29.80 47.54 53.33 59.93 71.24 79.26 83.99 88.88 90.66 72.5 32.43 50.33 56.12 62.78 73.77 81.15 85.39 89.93 91.56 75.0 35.71 53.49 59.24 65.95 76.34 83.06 86.82 90.99 92.46 77.5 39.87 57.21 62.84 69.32 78.96 84.99 88.37 92.07 93.38 80.0 44.60 61.80 67.19 72.89 81.56 86.91 89.87 93.15 94.31 82.5 49.97 67.02 72.00 76.71 84.16 88.87 91.45 94.28 95.28 85.0 55.74 72.85 77.10 80.77 86.90 90.79 93.02 95.35 96.20 87.5 62.09 78.67 82.16 84.88 89.60 92.65 94.54 96.37 97.06 90.0 68.79 84.00 86.80 88.75 92.11 94.45 95.94 97.32 97.83 92.5 75.98 88.81 90.93 92.30 94.51 96.21 97.23 98.17 98.52 95.0 83.06 93.19 94.60 95.48 96.74 97.90 98.38 98.92 99.12 97.5 90.17 97.08 97.91 98.40 98.82 99.12 99.41 99.60 99.69 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 12 to 24 hours

2.5 1.50 1.92 2.25 2.88 6.25 7.87 8.25 10.69 12.49 5.0 2.93 5.04 6.32 7.77 12.55 15.89 18.06 22.30 25.25 7.5 4.37 8.15 10.41 12.67 18.77 23.72 27.33 33.00 36.91 

10.0 5.82 11.22 14.47 17.66 25.00 31.15 35.57 42.09 46.84 12.5 7.24 14.21 18.50 22.66 31.01 37.85 42.69 49.34 54.70 15.0 8.57 16.80 21.98 27.19 36.28 43.72 49.00 55.28 60.83 17.5 9.68 18.86 24.84 30.94 40.58 48.43 54.23 60.09 65.38 20.0 10.67 20.60 27.14 33.97 44.09 52.25 58.86 64.35 69.16 22.5 11.61 21.93 28.77 36.04 46.70 55.14 63.01 68.49 72.53 25.0 12.32 22.91 29.76 37.04 48.37 57.29 66.57 72.67 75.92 27.5 12.81 23.91 30.71 37.70 49.65 58.80 69.38 76.46 79.21 30.0 13.22 24.96 31.57 38.23 50.52 59.72 71.30 79.44 82.06 32.5 13.52 25.88 32.34 38.58 51.07 59.97 72.34 81.43 84.32 35.0 13.84 26.90 33.26 39.16 51.55 60.28 72.89 82.42 85.93 37.5 14.30 27.82 34.20 39.87 51.91 60.41 73.08 82.64 86.77 40.0 14.99 28.74 35.22 40.73 52.19 60.71 73.10 82.70 87.06 42.5 15.84 29.62 36.32 41.67 52.60 61.26 73.16 82.80 87.18 45.0 16.83 30.46 37.40 42.58 53.07 62.08 73.53 82.90 87.30 47.5 17.81 31.25 38.39 43.47 53.59 62.60 74.05 83.00 87.53 50.0 18.99 32.52 39.52 44.49 54.46 63.50 74.77 83.40 87.93 52.5 20.49 34.16 40.90 45.76 55.67 64.49 75.71 83.77 88.49 55.0 22.22 36.20 42.69 47.39 57.27 65.87 76.82 84.67 89.11 57.5 24.28 38.74 44.83 49.64 59.26 67.65 77.97 85.53 89.75 60.0 26.61 41.35 47.14 52.07 61.46 69.98 79.04 86.29 90.36 62.5 29.21 43.76 49.53 54.66 63.75 72.21 80.22 87.09 90.96 65.0 31.64 45.93 51.72 57.04 66.07 74.57 81.49 87.88 91.54 67.5 34.21 48.12 53.68 59.25 68.27 76.65 82.74 88.66 92.14 70.0 36.87 50.26 55.70 61.22 70.36 78.53 84.02 89.35 92.73 72.5 39.58 52.89 58.10 63.41 72.53 80.18 85.36 90.17 93.31 75.0 41.85 55.65 60.76 65.76 74.70 81.85 86.61 90.95 93.88 77.5 44.08 58.69 63.80 68.46 76.91 83.43 87.81 91.75 94.49 80.0 46.33 61.82 67.13 71.35 79.22 85.04 89.09 92.64 95.08 82.5 48.66 65.31 70.72 74.57 81.67 86.76 90.41 93.68 95.70 85.0 51.20 68.96 74.41 77.89 84.19 88.58 91.74 94.63 96.33 87.5 55.46 73.39 78.41 81.47 86.84 90.46 93.10 95.59 96.99 90.0 61.33 78.37 82.57 85.14 89.54 92.37 94.47 96.53 97.63 92.5 68.64 83.68 86.91 88.94 92.26 94.27 95.84 97.45 98.30 95.0 77.31 89.13 91.22 92.68 94.99 96.15 97.21 98.34 98.96 97.5 87.25 94.79 95.58 96.46 97.76 98.05 98.59 99.23 99.62 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 24 to 72 hours 2.5 1.15 1.71 2.06 2.52 4.18 6.17 8.83 11.68 14.55 

5.0 2.23 4.06 4.87 5.91 8.82 12.81 17.63 22.99 27.19 7.5 3.27 6.23 7.44 8.98 13.10 18.71 25.43 33.09 38.32 

10.0 4.21 8.09 9.62 11.61 16.78 23.67 31.96 41.72 47.76 12.5 4.95 9.52 11.35 13.75 19.81 27.57 36.99 48.27 54.74 15.0 5.61 10.66 12.83 15.56 22.25 30.34 40.57 52.64 59.09 17.5 6.16 11.47 13.98 17.00 24.12 32.11 42.78 55.45 61.64 20.0 6.68 12.29 15.12 18.42 25.75 33.52 44.41 57.24 63.06 22.5 7.25 13.05 16.24 19.79 27.28 34.60 45.36 57.91 63.20 25.0 8.02 14.01 17.44 21.22 28.84 35.60 46.12 58.42 63.25 27.5 8.86 15.18 18.74 22.64 30.45 36.97 47.15 59.07 63.27 30.0 9.73 16.59 20.19 24.22 32.12 38.73 48.59 59.77 63.49 32.5 10.78 18.03 21.65 25.72 33.81 40.51 50.29 60.68 63.98 35.0 11.82 19.61 23.23 27.36 35.47 42.43 52.47 62.31 65.15 37.5 12.74 21.00 24.81 28.97 37.06 44.33 54.71 64.06 66.58 40.0 13.61 22.25 26.30 30.65 38.76 45.94 56.59 65.86 68.33 42.5 14.65 23.49 27.83 32.30 40.57 47.36 57.99 67.42 69.97 45.0 15.75 25.02 29.68 34.29 42.41 49.10 59.20 68.89 71.63 47.5 17.32 26.97 31.88 36.44 44.48 51.17 60.54 70.17 73.25 50.0 19.48 29.64 34.38 38.83 46.75 53.47 62.19 71.65 74.99 52.5 21.94 32.98 37.54 41.54 49.00 56.10 64.23 73.37 76.76 55.0 24.11 36.28 40.64 44.31 51.24 58.88 66.77 75.65 78.98 57.5 25.91 39.02 43.27 46.86 53.71 61.49 69.52 78.00 81.23 60.0 27.32 41.15 45.34 49.20 56.08 63.81 72.02 80.37 83.40 62.5 28.14 42.75 47.20 51.34 58.34 66.10 74.30 82.51 85.40 65.0 28.70 43.70 48.39 53.03 60.37 68.12 76.32 84.33 87.15 67.5 29.75 44.83 49.70 54.68 62.31 70.07 78.11 85.81 88.55 70.0 31.07 46.31 51.28 56.32 63.98 71.82 79.56 87.12 89.87 72.5 32.46 48.21 53.26 58.11 65.61 73.55 80.84 88.12 90.92 75.0 34.33 50.37 55.44 60.04 67.28 75.03 81.97 88.99 91.76 77.5 36.73 53.06 58.10 62.37 69.31 76.66 83.12 89.85 92.55 80.0 39.39 56.09 61.07 65.01 71.49 78.24 84.18 90.64 93.25 82.5 43.04 59.72 64.56 68.18 74.13 80.17 85.53 91.48 93.89 85.0 47.80 63.80 68.43 71.72 77.08 82.36 87.11 92.51 94.63 87.5 53.76 68.53 72.80 75.75 80.47 84.95 88.95 93.65 95.48 90.0 60.88 73.73 77.56 80.17 84.17 87.77 91.03 94.89 96.38 92.5 69.50 79.62 82.63 84.91 88.16 90.86 93.32 96.25 97.33 95.0 79.12 86.16 87.85 89.76 92.17 93.97 95.65 97.65 98.32 97.5 89.40 93.03 93.19 94.75 96.30 97.15 98.08 99.10 99.32 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
First- through fourth-quartile storms combined; storm duration 0 to 72 hours

2.5 1.08 2.04 2.58 3.34 4.69 6.37 7.81 10.30 12.16 5.0 2.35 4.32 5.47 6.84 9.74 13.58 16.97 21.38 24.48 7.5 3.59 6.56 8.32 10.27 14.68 20.49 25.56 31.57 35.63 

10.0 4.82 8.78 11.16 13.68 19.47 26.83 33.19 40.38 45.16 12.5 5.92 10.85 13.80 16.85 23.94 32.42 39.68 47.57 52.72 15.0 6.92 12.77 16.23 19.72 27.91 37.21 45.23 53.41 58.54 17.5 7.80 14.43 18.29 22.14 31.01 41.00 49.56 57.96 62.97 20.0 8.60 15.99 20.23 24.32 33.59 44.11 53.16 61.80 66.74 22.5 9.31 17.38 21.89 26.21 35.63 46.55 55.92 65.02 69.84 25.0 10.06 18.75 23.51 28.07 37.35 48.54 58.09 67.80 72.62 27.5 10.87 20.11 25.00 29.79 38.88 50.23 59.80 70.07 75.06 30.0 11.70 21.51 26.51 31.41 40.52 51.68 61.22 71.87 76.92 32.5 12.51 22.77 27.81 32.85 42.01 52.90 62.34 73.12 78.10 35.0 13.35 24.09 29.22 34.30 43.56 54.27 63.76 74.21 79.02 37.5 14.16 25.27 30.47 35.54 44.99 55.49 65.16 75.15 79.64 40.0 14.96 26.51 31.85 36.89 46.42 56.80 66.62 76.11 80.22 42.5 15.78 27.58 33.21 38.24 47.68 58.03 67.98 77.06 80.86 45.0 16.71 28.90 34.80 39.80 49.13 59.31 69.33 78.12 81.72 47.5 17.89 30.35 36.44 41.44 50.66 60.49 70.35 79.07 82.56 50.0 19.41 32.28 38.33 43.33 52.45 61.97 71.60 80.06 83.51 52.5 21.16 34.45 40.32 45.28 54.39 63.51 72.89 81.15 84.53 55.0 22.94 36.99 42.49 47.39 56.57 65.39 74.37 82.30 85.61 57.5 24.82 39.38 44.67 49.56 58.80 67.56 76.05 83.52 86.75 60.0 26.62 41.64 46.83 51.75 61.09 69.85 77.89 84.82 88.01 62.5 28.29 43.62 49.00 53.94 63.38 72.11 79.55 86.10 89.22 65.0 29.86 45.38 50.95 56.07 65.59 74.32 81.14 87.25 90.31 67.5 31.76 47.16 52.88 58.23 67.77 76.38 82.65 88.36 91.31 70.0 33.75 49.16 54.81 60.32 69.87 78.21 84.02 89.37 92.17 72.5 36.00 51.52 56.94 62.47 71.97 80.00 85.35 90.35 92.90 75.0 38.51 54.15 59.24 64.72 73.98 81.61 86.69 91.30 93.55 77.5 41.45 57.17 62.09 67.30 76.10 83.25 88.02 92.25 94.20 80.0 44.54 60.42 65.22 70.08 78.24 84.84 89.34 93.15 94.86 82.5 48.24 64.13 68.85 73.31 80.60 86.54 90.72 94.08 95.54 85.0 52.41 68.26 72.78 76.77 83.07 88.30 92.09 94.98 96.22 87.5 57.68 72.90 77.10 80.53 85.81 90.21 93.49 95.87 96.93 90.0 64.02 77.90 81.55 84.43 88.65 92.18 94.92 96.75 97.61 92.5 71.71 83.28 86.22 88.48 91.66 94.22 96.37 97.65 98.29 95.0 80.43 88.80 90.85 92.47 94.62 96.21 97.81 98.54 98.96 97.5 90.01 94.42 95.53 96.53 97.64 98.21 99.26 99.44 99.65 

Supplement 5. Trimmed and smoothed percentiles for empirical hyetograph analysis, 1959–86.—Continued[The interval is the center of the percent-of-storm-duration interval; --, no data]

Interval Percentile 10th 20th 25th 30th 40th 50th 60th 70th 75th 
Prepared by the Publications Staff, 

North Dakota District Office

for the Texas District Office:

U.S. Geological Survey

8027 Exchange Drive

Austin, TX 78754–4733

Information regarding water resources in Texas is available at URL

http: //tx.usgs.gov/