THE AMBER ADMINISTRATOR'S GUIDE

ROBERT. S DAVIS

PITTSBURGH NWSFO

E:mail Robert.Davis@noaa.gov

March 15, 1999

Table of Contents

Chapter 1. Introduction to AMBER 3 - 9

Chapter 2. The AMBER Data Access Software 10 - 11

Chapter 3. The AMBER Stream Basin Database 12 - 26

Chapter 4. The AMBER ABR Database 27 - 28

Chapter 5. Creation of the AMBER Stream Basin Database 29 - 34

Chapter 6. References 35

Appendix A. AMBER MSDOS Program Summary 36 - 39

Appendix B. AMBER Programmer's Guide 40 - 58

B.1 County Database 40

B.2 River Forecast Database 40 - 41

B.3 Primary Stream Database 41 - 43

B.4 Subdivision Database 43 - 44

B.5 Topographic Map Database 44 - 45

B.6 Observing Site Database 45 - 47

B.7 MAP Database 47 - 48

B.8 Major Stream Database 48 - 50

B.9 Urban Area Database 50 - 51

B.10 WSR-88D Bin Database 51 - 53

B.11 STATES. AMB file 53 - 56

B.12 TOPO.AMB file 56 - 57

B.13 COUNTIES.xx files 57

B.14 Primary ABR Database 57 - 59

B.15 Subdivison ABR Database 59

B.16 Urban Area ABR Database 59 - 60

B.17 Flash Flood Guidance Files 60

B.18 AMBER Warning/Alert Files 61 - 62

Appendix C. AMBER DOS to UNIX Software Transfer 63 -- 64

**Chapter 1.0 INTRODUCTION to AMBER**

AMBER is a software application that uses high resolution rainfall
estimates from the Weather Surveillance Radar, 1988 Doppler (WSR-88D) to
determine where flash flooding is likely. In order to evaluate the flash
flood threat, AMBER computes the Average Basin Rainfall (ABR) for user
defined basins; for example, in Pittsburgh AMBER computes ABR for 2,427
streams every 5-6 minutes for the Pittsburgh National Weather Service
Forecast Office (NWSFO) area of responsibility. The likelihood of
flooding is established by comparing the ABR with Flash Flood Guidance
(FFG), i.e., the ABR needed to bring a stream to bankfull. In addition
to determining flash flood potential for streams, AMBER calculates the
ABR for a full range of hydrologic scales, from river forecast areas to
urban areas.

**1.1 HISTORY OF AMBER**

AMBER has evolved from 13 years of operational development at the
Pittsburgh NWFSO. From 1983 to 1992, rainfall estimates from the Radar
Data Processor II (RADAP-II) were used operationally to detect where
flash flooding was likely. Several publications resulted from this
research, including Davis and Rossi (1985), Davis and Drake (1988),
Davis (1993), Davis and Jendrowski (1996), and Davis (1997). The
software was upgraded in 1993 to take advantage of the higher resolution
rainfall estimates from the WSR-88D radar. The one degree by one
kilometer grid of the WSR-88D has nearly four times the resolution of
the RADAP-II polar grid.

Previous research has revealed several important factors, which have
shaped AMBER\'s current structure. First, the time scale of the one-hour
rainfall product of RADAP-II was too large to detect rapidly developing
flash floods. RADAP\'s ten minute rainfall product provided much better
guidance. Second, flash floods typically occur in small watersheds (5 to
30 mi^2^). The forecaster must have access to these small watershed
boundaries to determine flash flood potential. Third, forecasters need
to estimate the volume of rainfall (ABR) within these small watersheds
to effectively determine the flash flood threat. Finally, digital
WSR-88D radar rainfall estimates can provide sufficient time and space
resolution to detect flash flood potential.

2.  **THE AMBER STREAM BASIN DATABASE**

The heart of the AMBER program is a systematic analysis of all stream
watersheds, 5 mi^2^ in area or larger, in the NWSFO area of flash flood
warning responsibility. In highly urbanized areas, streams as small as 1
mi^2^ are included in the stream basin database. The flash flood threat
can be quantified only if Average Basin Rainfall (ABR) can be estimated.
And ABR can be estimated, only if the watershed boundaries for each
stream are known and the distribution of rainfall within that watershed
can be estimated with some accuracy.

The AMBER flash flood watershed analysis starts with the Mean Areal
Precipitation (MAP) areas used by the National Weather Service's River
Forecast Centers (RFCs). Figure 1 shows the outline of the Dashield's
(DSHP1) MAP area near Pittsburgh. The Pittsburgh NWSFO AMBER database
in­cludes 86 MAP areas.

Each MAP area is divided into primary stream (\<200 mi^2^) or major
stream (≥200 mi^2^) watersheds. Chartiers Creek at Carnegie in Figure 1
is a major stream (basin #509, where the area is 257 mi^2^) that covers
two-thirds of the entire Dashield\'s MAP (basin #104) area. Since the
response time of major streams is relatively slow, flood warnings,
rather than flash flood warnings, are typically issued for these larger
streams. The Pittsburgh NWSFO AMBER database includes 35 major streams.

Flash flood streams in the AMBER database are either primary streams or
their subdivisions (i.e., tributaries). Primary streams are less than
200 mi^2^ in area, but the great majority are less than 50 mi^2^. Figure
2, shows the 34 primary streams defined within the Dashield's MAP area.
Pittsburgh's AMBER database contains 1163 primary streams.

![](media/image1.emf){width="2.2375in"
height="3.7444444444444445in"}![](media/image2.emf){width="2.6069444444444443in"
height="3.7444444444444445in"}

Figure 1. Dashield's MAP area with Figure 2. Primary streams in the

the Chartier's creek major stream. Dashield's MAP area

Stream subdivisions are smaller tributaries contained within primary
streams or other stream subdivisions. Figure 3 shows the 40 stream
subdivi­sions contained within the Dashield's MAP area. The Pittsburgh
AMBER database contains 1,264 subdivisions.

![](media/image3.emf){width="2.6368055555555556in"
height="3.9694444444444446in"}![](media/image4.emf){width="2.317361111111111in"
height="3.9694444444444446in"}

Figure 3. Dashield's MAP Figure 4. Dashield's MAP

Subdivisions. Urban Areas.

Urban areas can experience dangerous flash flooding when storm sewers
back up from intense rainfall. Many of these urban areas are not
directly impacted by stream flooding. AMBER calculates average rainfall
in these urban areas to alert the forecasters to possible urban
flooding.

The Pittsburgh AMBER database includes 141 urban areas, see Figure 4 for
examples.

**1.3 ABR COMPUTATIONS**

AMBER uses the WSR-88D Digital Hybrid Scan Reflectivity product (DHR) as
input for estimating rainfall. The DHR provides one degree by one
kilometer reflectivity data from the Hybrid Scan produced by the
Precipitation Preprocessing algo­rithms of the WSR-88D. Rain­fall
accumulations are computed from successive DHR products, following as
closely as possible the current Precip­itation Rate and Precipitation
Accumu­lation algorithms. However, data are output at 1^o^ x 1 km
resolution, instead of the 2 km data associated with the current
Precipitation Rate algorithm. The computed ABR values represent an area
weighted average accumu­lation of all radar rainfall estimates in a
watershed, including zero accumu­lations. The 5-6 minute ABR values are
summed to create rainfall accumulations for 0.5, 1,2,3 and 6 hours, and
then compared with the RFC\'s 1, 3 and 12 hour FFG. A complete
description of the ABR computations can be found in Chapter 4.

**1.4 AMBER OUTPUT**

At the completion of each radar volume scan, any stream or urban area
whose ABR exceeds 60% of FFG is output to the SAC computer screen. An
output display table contains the stream basin number, state and county
of the stream location, and the ABR and FFG for each time period. A
yellow alert level is reached when ABR is 80% of FFG, and a red alert is
reached when ABR exceeds 100% of FFG. By viewing the output ABR vs. Time
display, the forecaster can quickly assess total accumulation, rate of
accumulation, rainfall duration, and comparison to FFG over the past 6
hours. Chapter 2 provides a listing of programs that can be used to
display AMBER output. A detailed summary of the data stored in the ABR
database can be found in Chapter 4.

![](media/image5.emf){width="4.095138888888889in"
height="2.6958333333333333in"}

Figure 5. AMBER output for the Etna , PA Flash flood of May 30, 1986 on

Little Pine Creek. Radar Estimates from RADAP-II data.

Figure 5 illustrates RADAP-II AMBER output for the Etna flash flood
event of May 30, 1986. During this event, a 10 foot wall of water
inundated Saxonburg Boulevard near Etna, PA during rush hour, causing 9
fatalities. Notice that the slope of the ABR curve (the rain­fall rate)
is steeper than the FFG slope from the onset of the event. Furthermore
the yellow alert level was exceeded 37 minutes before the actual flood
wave occurred. While the red alert level was 28 minutes before the flood
event. This demonstrates that AMBER can pro­vide significant lead time in
serious short-fused flood events.

5.  **OPERATIONAL APPLICATIONS**

The ABR output from AMBER supports the entire range of hydrologic
functions of the forecast office, from flash flooding to large scale
river flooding.

AMBER output for primary streams, subdivisions, and urban areas provides
reliable guidance for issuing flash flood warnings. Before AMBER,
forecasters relied pri­marily on point rainfall amounts from rain gages,
or maximum radar estimates to make flash flood warning decisions. Using
the ABR calculations from AMBER, forecasters can obtain a better
estimate of the actual volume of rainfall oc­curring within a stream
basin, which is directly related to the volume of water in the flood
hydrograph.

Although designed specifically for detection of flash floods, AMBER can
be used to detect stream flooding that occurs over time spans of more
than 6 hours. AMBER can compare ABR with 6 to 12-hour FFG to determine
the risk of stream flooding. In areas not prone to frequent flash
flooding, AMBER can also be used to determine the flood potential for
low lying areas prone to significant ponding of water.

The MAP computations in AMBER can be used at the forecast office to
provide quick updates to river forecasts. The MAP esti­mates can be
compared with the Quantitative Precipitation Forecasts (QPF) that were
used to produce the river forecasts.

AMBER provides several pieces of information to the flash flood
forecaster currently not readily available to the field forecaster from
any other source. The WSR-88D rainfall products on the PUP of the
WSR-88D are displayed on map backgrounds of political county maps. The
PUP has no map backgrounds of the small flash flood watersheds for
display of the rainfall products. AMBER provides a means of mapping all
WSR-88D rainfall estimates directly into the stream watersheds impacted
by the heavy rainfall. A complete description of the definition of these
watersheds is found in Chapter 3. These flash flood watersheds include
major streams (those stream watersheds greater than 200 mi^2^ in area),
primary streams (watersheds less than or equal to 200 mi^2^ in area),
subdivisions (smaller tributaries of primary streams), and urban areas
that may be impacted by urban flooding rather than stream flooding.

Second, the forecaster must compare rainfall to FFG to determine the
potential for flash flooding. By definition, FFG is the Average Basin
Rainfall (ABR) in a stream watershed in a specific period of time (e.g.,
1-hour or 3-hours) needed to bring a stream to a bankfull condition. The
forecaster has no means of estimating ABR. Flash flood warnings are
often based on point measurements from rain gages, or maximum observed
rainfall from the WSR-88D. The WSR-88D rainfall display shows the areal
distribution of rainfall, but no map backgrounds of small streams are
available for this display. Small point measurements should not be used
for comparison with FFG to determine the flash flooding threat, only the
average rainfall over the watershed is a valid hydrologic comparison.
AMBER provides a method of computing ABR for the forecaster by using
detailed rainfall estimates from the DHR product of the WSR-88D.

Third, the comparison of ABR with FFG will tell the forecaster not only
if flash flooding may occur, but also the degree of flash flooding.
Typically, if ABR is 1 inch over FFG, significant flash flooding will
occur. If ABR is 2 inches over FFG, severe flash flooding will likely
result. And if ABR reaches 3 inches over FFG catastrophic flash flooding
may well result. The comparison of ABR with FFG will provide the
forecaster with a direct measurement of the severity of flash flooding.

Fourth, because of the small time steps of the rainfall estimates
produced from the DHR product (5-6 minutes), the forecaster can observe
the high rainfall rates associated with flash flooding before the
flooding actually begins. By alarming the forecaster when ABR in a
watershed reaches 60%, 80% and 100% of FFG, the forecaster can warn
before actual flooding begins increasing warning lead time. The user may
select these percentage of FFG alert levels through AMBER adaptation
data. These short time durations of rainfall allow the forecaster to
examine rainfall durations of any time step from 5-60 minute rainfall
totals, rather than waiting for the one-hour time steps in the WSR-88D
PUP displayable rainfall products. For example, if the ABR reaches
1-hour FFG in 60 minutes, minor flash flooding should begin. If the ABR
reaches 1-hour FFG in 20 minutes, significant flash flooding may already
be underway.

The time duration of the heavy rainfall is of critical importance to the
flash flood forecaster. The forecaster must be able to detect these
short time duration (15-30 minute) bursts of rain to effectively issued
flash flood warnings. The WSR-88D has the capability to detect these
heavy rainfall bursts, and AMBER gives the field forecaster access to
this information for the first time. The AMBER software is set to
automatically examine rainfall time durations of 20, 40, 60, 120 and 180
minutes. There time durations may be set for any 5 durations of less
than 6 hours in the AMBER adaptation data. Using AMBER, the forecaster
is no longer limited to the fixed time period of the 1-hour and 3-hour
rainfall products available on the WSR-88D.

All of these benefits to the forecaster come at a price. Each forecast
office must perform an analysis of flash flood watersheds in their
forecast area. A lot of work is required to create a watershed analysis
for a NWSFO warning area. However, the watershed analysis can be more
easily accomplished on clear weather days, than to attempt to find that
same watershed in the middle of a busy flash flood event. When the
WSR-88D indicates that 4 inches of rain has fallen in the past hour, the
forecaster must be able to quickly and accurately determine what streams
will be impacted by that rainfall. AMBER automates this process, freeing
the forecaster from having to search out the necessary watershed
information. Chapter 5 provides guidelines for the construction of the
AMBER database for any NWSFO.

This introduction gives a brief overview of the AMBER programs. A more
detailed look at each aspect of AMBER is available in the following
chapters.

Chapter 2 describes the software that is currently available to access
the rainfall data stored in the AMBER ABR database. Any NWSFO is free to
write their own access software. A complete description of the ABR data
stored in the database is given in Chapter 4 for those who would like to
write their own data access programs. The programs listed here are the
current list of programs in use at the Pittsburgh NWSFO to operationally
examine the ABR database. This alphanumeric user interface will be
updated in the future to include a graphics user interface for AMBER.

Chapter 3 describes the AMBER stream basin database. This chapter shows
a method of logically defining all streams in the NWSFO warning area,
insuring that no streams, smaller than a user defined watershed area,
will be excluded from the stream basin database. After the stream
watersheds are defined, the WSR-88D one-degree by one-kilometer grid
rainfall estimates (from DHR product), are mapped directly into the
defined watersheds.

Chapter 4 describes the computation of ABR and the AMBER ABR database
where the results of those computations are stored.

Chapter 5 outlines the procedure for building the AMBER stream basin
database from scratch. This chapter is provided as a guideline for the
system administrator given the task of creating an AMBER database for
their forecast office.

Chapter 6 gives some references to publications that contain some case
studies of flash flood events where radar rainfall estimates were used
to estimate the flash flood threat.

Appendix A is a summary of the DOS programs available for construction,
maintenance and use of the AMBER databases.

Appendix B is a Fortran programmer's reference of all the AMBER stream
basin database, and the AMBER ABR database.

Appendix C outlines the procedures for transferring all of the DOS amber
databases to a UNIX platform, so the databases can be used by the
real-time AMBER software that runs in the UNIX environment.

**Chapter 2.0 ACCESSING THE AMBER DATABASE**

This chapter provides the current list of the programs used
operationally at the Pittsburgh NWSFO to access the rainfall data stored
in the AMBER Average Basin Rainfall (ABR) database. The section heading
is the name of the program that must be entered by the forecaster to
execute the program. A description of the program's output is given in
each section. All of these programs were written in HP Fortran. A
complete description of the procedure used to compute ABR and details on
what is stored in the ABR database can be found in Chapter 4.

**2.1 ABR**

Prints a listing of 50 primary streams and 50 subdivisions with the
highest amount of ABR that has accumulated between the user selected
starting and ending times. Streams are ordered by amount of ABR. A
negative time can be entered for the starting time if the desired
starting time is on the previous GMT calendar day.

**2.2 URBAN**

Prints a listing of 50 major streams and 50 urban areas or Z/R rain
gages with the highest amount of ABR that has accumulated between the
user selected starting and ending times. Streams and gages are ordered
by amount of ABR. A negative time can be entered for the starting time
if the desired starting time is on the previous GMT calendar day.

**2.3 RATE1**

Displays a listing of all primary streams and all subdivisions with a
rainfall rate of 1 inch/hour or more during the most recent volume scan.
The one hour rainfall rate is determined by multiplying the ABR, for
each stream or rain gage, by 3600 and dividing that result by the number
of seconds in the current volume scan. The forecaster types RATE1 at the
keyboard, and output for the most recent volume scan is displayed at the
screen.

**2.4 RATE**

This program is an automated version of the RATE1 program that runs in
the background, and automatically prints a listing of all primary
streams and all subdivisions with a rainfall rate of 1 inch/hour or more
during the most recent volume scan. The one hour rainfall rate is
determined by multiplying the ABR, for each stream or rain gage, by 3600
and dividing that result by the number of seconds in the current volume
scan. Once this program is started, the rainfall rate data will
automatically print each volume scan until the program is stopped.

**2.5 NOW**

Prints a listing of the 50 primary streams and 50 subdivisions with
highest amount of ABR in the user selected time interval stored in the
setdate program. The user selected time interval can be set for any time
period from 0 to 180 minutes. The streams are output in order of ABR
amount. Program defaults to the current date stored in setdatea and most
recent volume scan for that date. The product output for each stream
also included the 1-hour FFG and the actual time duration of the
observed rainfall in minutes.

**2.6 NOW1**

Prints a listing of the 50 primary streams and 50 subdivisions with
highest amount of ABR in the past hour in order of ABR amount. Program
defaults to the current date and most recent volume scan. The product
output for each stream also included the 1-hour FFG and the actual time
duration of the observed rainfall in minutes.

**2.7 NOW2**

Prints a listing of the 50 primary streams and 50 subdivisions with
highest amount of ABR in the past 2 hours in order of ABR amount.
Program defaults to the current date and most recent volume scan. The
product output for each stream also included the 2-hour FFG and the
actual time duration of the observed rainfall in minutes.

**2.8 NOW3**

Prints a listing of the 50 primary streams and 50 subdivisions with
highest amount of ABR in the past 3 hours in order of ABR amount.
Program defaults to the current date and most recent volume scan. The
product output for each stream also included the 3-hour FFG and the
actual time duration of the observed rainfall in minutes.

**2.9 SETDATE**

Allows the forecaster to set the date used by the ABR, URBAN, NOW, NOW1,
NOW2, and NOW3 programs for the end time of the displayed rainfall. The
most current date should be entered for real time data. However the
forecaster can set the date to any calendar date for the past 3 months,
to display radar rainfall estimates for past events. The program also
allows the forecaster to set the time interval for the NOW program.

**Chapter 3.0 The AMBER STREAM BASIN DATABASE**

The AMBER stream basin database consists of data files containing
information for all streams, urban areas and observing sites for which
ABR calculations are made and stored in the AMBER ABR database. This
information includes lists of political county names, topographic maps
used to extract data, river observing sites, mean areal precipitation
areas, major streams, primary streams, stream subdivisions, urban areas,
rain gage sites used for Z/R comparisons, and data files defining the
location of the WSR-88D DHR rainfall grid into each stream watershed.

The AMBER stream database is created and maintained on a PC in the MSDOS
environment. A description of all programs used to create and maintain
the stream basin database may be found in Appendix A. The software was
initially written in the PC environment because a UNIX workstation was
not available in the forecast office. All the MSDOS programs are written
in Microsoft Fortran version 5.1. Each of these programs can easily be
recompiled to run on the UNIX SAC platform if desired. However, the PC
environment provides for easy backup up of the database, as the entire
database will fit on one 1.4 MB floppy disk. Additions and corrections
to the database can be easily made on any PC and then transferred to the
SAC using some form of FTP. Appendix C details the procedure for
transferring the stream basin database from the PC to a UNIX
workstation.

Most of the data in the stream basin database has been extracted by hand
from USGS 7.5 minute topographic maps. This includes, all stream
watershed information and all WSR-88D DHR rainfall grid assignments.
Three programs allow the user to examine the contents of all the stream
basin databases, STATUS, AMBER and BINS. This chapter describes these
three programs and the contents of the AMBER stream basin database.

**3.1 STATUS**

The STATUS program displays a summary of the STATES.AMB file, the
control file for the AMBER stream basin database. This file contains
information such as the WSR-88D latitude, longitude, and elevation above
sea level. STATES.AMB also contains a count of how many streams,
counties, "topomaps," etc. are in the current stream basin database.
STATUS displays a summary of all the stream basin database categories,
along with a current count and allowable range of values for each
category.

The STATUS program provides three main options, (1) display a database
summary, (2) print the master topographic map grid, (3) print the county
list for a state. Options (2) and (3) are used by the system
administrator for initially setting up the AMBER stream basin database
and are of little use to AMBER user. The summary of the database given
by option (1) shows the user the valid stream numbers that can be used
for each AMBER category and the highest valid stream number currently in
use. This is the summary for the Pittsburgh NWSFO, with the last column
added to provide the section of this documentation that provides the
description of the database:

\*\*\*\* Current AMBER Stream Basin Database \*\*\*\*

CATEGORY CURRENT ALLOWABLE RANGE (SECTION)

COUNTIES === 106 1 - 9999 3.2.1

RIVER SITES === 44 1 - 9999 3.2.2

M.A.P. AREAS === 188 100 - 499 3.2.3

MAJOR STREAMS === 534 500 - 999 3.2.4

PRIMARY STREAMS === 2291 1000 - 3999 3.2.5

SUBDIVISIONS === 6296 5000 - 9999 3.2.6

URBAN AREAS === 4665 4000 - 4999 3.2.7

OBSERVING SITES === 761 1 - 9999 3.2.8

TOPO QUADS === 828 1 - 9999 3.2.9

For example, primary streams may be assigned any number in the range
from 1000 to 3999. However, the primary streams must be numbered
consecutively starting with primary stream number 1000. The current data
base has 1,292 primary streams numbered from 1000 to 2291. If a new
primary stream is added to the current database, it will be assigned the
number 2292. The primary stream database is described in section 3.2.5.

**3.2 AMBER**

The AMBER program displays or prints the contents of the each of the
nine categories of the AMBER stream basin database displayed by the
STATUS program. The purpose and content of each category is provided in
the following sections. A summary of how the stream basin watersheds are
defined is included in each of the stream basin sections including MAP
areas, major streams, primary streams, subdivisions, and urban areas.

**3.2.1 COUNTY DATABASE**

Purpose: To provide the AMBER program with a listing of all counties
within the 230km range of the WSR-88D.

Content: Each county is assigned a unique integer number, starting from
1 to the total number of counties in the database. For each county the
following information is stored:

1\. County name.

2\. County FIPS code.

3\. Two letter state identifier.

4\. Office of primary warning responsibility.

5\. Office of backup warning responsibility.

6\. First zone code for the county. Note: If \> 2 zones are assigned to
a county, the

7\. Second zone code for the county. 1^st^ and last zones numbers are
used.

**3.2.2 RIVER SITES DATABASE**

Purpose: The River Sites database provides a listing of all river
forecast points, locks and dams within the area of NWSFO warning
responsibility.

Content: The following information is stored in the River Site database:

1\. Name of river forecast point.

2\. Flood Stage

3\. Five E-19 alert stages. (For dams significant pool elevations are
used)

4\. River mile location of the gage.

5\. Number of the River Site in the Reporting Site database. All River
Site entries will have a corresponding entry in the Reporting site
database.

6\. Downstream River Site number.

7\. Type of river site (1 = daily forecast point, 2 = non-daily forecast
point, 3 = non forecast stage point, 4 = dam or reservoir.)

8\. MAP containing river site.

9\. Upstream river site number.

10\. River number and river name.

**3.2.3 MEAN AREAL PRECIPITATION AREA DATABASE**

Definition: The Mean Areal Precipitation (MAP) area is a hydrologic area
used by the River Forecast Center (RFC) , to compute forecast river
stages provided to the NWSFO as guidance. AMBER calculates ABR for any
MAP area with a gaged outflow point. The RFC may divide some MAP areas
into parts for timing of runoff distributions. The headwaters portion of
the divided MAP areas may or may not be gaged. If they are not gaged,
AMBER combines the divided MAP areas into a single MAP.

![](media/image6.emf){width="3.995833333333333in"
height="2.6958333333333333in"}

Figure 6. Mean Areal Precipitation (MAP) areas Pittsburgh to New
Cumberland.

Figure 6 shows five MAP areas used by the Wilmington RFC from
Pittsburgh, PA, (PTTP1) to New Cumberland, WV, (NCUW2). New Cumberland
is divided into two sections, upper and lower, but AMBER treats this
divided MAP as a single MAP #102. AMBER performs basin average
calculations in each of these 4 MAP areas (#102 - #105) every 5-6
minutes. A typical area for a MAP in the Pittsburgh NWSFO warning area
is 400 to 700 mi^2^ .

Purpose: The AMBER MAP database provides a list of all gaged MAP areas
used by the RFC to produce river stage forecasts. AMBER divides the MAP
areas into Majors streams, Primary streams and Subdivisions. The ABR for
the MAP areas may be used to verify the Quantitative Precipitation
Forecast (QPF) in real time. If observed ABR is higher than the QPF, the
river forecast based on the QPF will underestimate the forecast stages.
If the ABR is significantly above the QPF, the forecaster may request
another river run from the RFC, based on the observed ABR.
Qualitatively, the forecaster at the NWSFO will know if the current
river forecast is too low or too high, by comparing observed ABR with
QPF.

Content: The MAP database includes the following elements.

1\. Name of the MAP (5 letter Handbook 5 ID)

2\. Name of the QPF area containing the MAP.

3\. AFOS identifier of the RRM product containing the MAP.

4\. Latitude and Longitude of the outflows points to seconds.

5\. AMBER MAP number of the next downstream MAP area.

6\. Counties containing the MAP area (up to 8 counties)

7\. River sites contains within the MAP (up to 4 sites)

8\. Inflow MAPs (up to 4 MAPs)

9\. AMBER number of topo map holding the MAP outflow point.

10\. Number of WSR-88D 1^o^ x 1km bins in the MAP.

11\. The AMBER MAP number.

12\. Area of the MAP in tenths of a square mile.

13\. Length of the river segment in tenths of a mile.

14\. Slope of the river segment in feet of drop per mile.

15\. MAP minimum and maximum radar azimuth and range.

16\. The 8 character name of the MAP subdivisions, for MAP 102 in Figure
5, NCUW2UPR and NCUW2LWR would be stored.

**3.2.4 MAJOR STREAMS DATABASE**

Definition: A Major Stream is defined as any watershed contained within
a single MAP area, that is greater than or equal to 200 mi^2^ in area.
The lower limit for a major stream is completely arbitrary and may be
modified to any area more realistic to the hydrologic characteristics of
the basins in the NWSFO area of warning responsibility. The major stream
category consists of streams with response times too slow to be
considered flash flood watersheds. A flash flood by definition is
supposed to occur within 6 hours of the start of the rainfall event. In
areas with very steep topography, the major stream area may be 300-400
mi^2^. In the midwest of the United States with little topography, this
area may only be 100 mi^2^.

Purpose: The purpose of the Major Stream database is to provide a
listing of streams to AMBER that are subject to stream flooding, but
usually not flash flooding. ABR computed for these streams can be
entered into a hydrologic stream simulation program such as ADVIS or
FLARE program to produce forecasts for any gaged streams.

Content: The Major Stream database includes the following elements;

1\. Stream name.

2\. Latitude/Longitude of stream mouth.

3\. Counties containing the watershed (up to 4)

4\. Number of primary streams contained in the major stream.

5\. If the stream is gaged, the Observing site number of gage.

6\. The downstream river site number below the stream mouth.

7\. AMBER Major Stream Number.

8\. AMBER MAP number containing this major stream.

9\. Number of WSR-88D bins in the watershed.

10\. List of AMBER topographic map number containing the watershed.

11\. Area of the watershed in tenths of a square mile.

12\. Length of Stream Thalweg.

13\. Slope of the stream in feet of fall per 1000 feet.

14\. Minimum and maximum radar azimuth and range of the watershed.

15\. List of the AMBER primary streams in the watershed.

**3.2.5 PRIMARY STREAM DATABASE**

Definition: A primary stream is any watershed contained within a MAP
area that is less than 200 mi^2^ in area. There is no lower limit on the
size of a primary stream . The area of the 1^o^ by 1km radar bins will
define the lower limit of stream size in which Average Basin Rainfall
(ABR) may be calculated. You must have at least one radar bin within the
watershed to perform an ABR calculation. Table 1 shows the area of the
WSR-88D 1km bins as a function of range from the radar. The following
series of figures shows how primary streams may be defined. A primary
stream can be any stream flowing into a major river between river
forecast points (Figure 7), or the streams above a river headwaters
forecast point (Figure 8). Primary streams do not have to be permanent
flowing streams. Dry arroyos and washes may be defined as primary
streams. Streams that flow into lakes or oceans are also defined as
primary

![](media/image7.emf){width="2.1875in"
height="2.0819444444444444in"}![](media/image8.emf){width="2.5569444444444445in"
height="2.1416666666666666in"}

Figure 7. Primary stream definition Figure 8. Primary stream definition

between river forecast points. above river headwaters.

streams (Figure 9). Any primary stream found to be greater than 200 mi2
is entered into the database as a major stream. The subdivisions of a
major stream are also entered into the stream watershed database as
primary streams (Figure 10).

Table 1. Area of WSR-88D 1^o^ x 1km Range Bins at 1km intervals (area in
mi^2^).

Range Area Range Area Range Area Range Area Range Area

1\-- .01 51\-- .35 101\-- .68 151\-- 1.02 201\-- 1.36 Note: radar bin at
range

2\-- .02 52\-- .35 102\-- .69 152\-- 1.03 202\-- 1.36 1km, with an area
of

3\-- .02 53\-- .36 103\-- .70 153\-- 1.03 203\-- 1.37 0.01mi^2^, is the
bin from

4\-- .03 54\-- .37 104\-- .70 154\-- 1.04 204\-- 1.38 1km to 2km.

5\-- .04 55\-- .37 105\-- .71 155\-- 1.05 205\-- 1.38

6\-- .04 56\-- .38 106\-- .72 156\-- 1.05 206\-- 1.39

7\-- .05 57\-- .39 107\-- .72 157\-- 1.06 207\-- 1.40

8\-- .06 58\-- .39 108\-- .73 158\-- 1.07 208\-- 1.41

9\-- .06 59\-- .40 109\-- .74 159\-- 1.07 209\-- 1.41

10\-- .07 60\-- .41 110\-- .74 160\-- 1.08 210\-- 1.42

11\-- .08 61\-- .41 111\-- .75 161\-- 1.09 211\-- 1.43

12\-- .08 62\-- .42 112\-- .76 162\-- 1.10 212\-- 1.43

13\-- .09 63\-- .43 113\-- .76 163\-- 1.10 213\-- 1.44

14\-- .10 64\-- .43 114\-- .77 164\-- 1.11 214\-- 1.45

15\-- .10 65\-- .44 115\-- .78 165\-- 1.12 215\-- 1.45

16\-- .11 66\-- .45 116\-- .79 166\-- 1.12 216\-- 1.46

17\-- .12 67\-- .45 117\-- .79 167\-- 1.13 217\-- 1.47

18\-- .12 68\-- .46 118\-- .80 168\-- 1.14 218\-- 1.47

19\-- .13 69\-- .47 119\-- .81 169\-- 1.14 219\-- 1.48

20\-- .14 70\-- .48 120\-- .81 170\-- 1.15 220\-- 1.49

21\-- .14 71\-- .48 121\-- .82 171\-- 1.16 221\-- 1.49

22\-- .15 72\-- .49 122\-- .83 172\-- 1.16 222\-- 1.50

23\-- .16 73\-- .50 123\-- .83 173\-- 1.17 223\-- 1.51

24\-- .17 74\-- .50 124\-- .84 174\-- 1.18 224\-- 1.51

25\-- .17 75\-- .51 125\-- .85 175\-- 1.18 225\-- 1.52

26\-- .18 76\-- .52 126\-- .85 176\-- 1.19 226\-- 1.53

27\-- .19 77\-- .52 127\-- .86 177\-- 1.20 227\-- 1.53

28\-- .19 78\-- .53 128\-- .87 178\-- 1.20 228\-- 1.54

29\-- .20 79\-- .54 129\-- .87 179\-- 1.21 229\-- 1.55

30\-- .21 80\-- .54 130\-- .88 180\-- 1.22 230\-- 1.55

31\-- .21 81\-- .55 131\-- .89 181\-- 1.22 231\-- 1.56

32\-- .22 82\-- .56 132\-- .89 182\-- 1.23 232\-- 1.57

33\-- .23 83\-- .56 133\-- .90 183\-- 1.24 233\-- 1.57

34\-- .23 84\-- .57 134\-- .91 184\-- 1.24 234\-- 1.58

35\-- .24 85\-- .58 135\-- .91 185\-- 1.25 235\-- 1.59

36\-- .25 86\-- .58 136\-- .92 186\-- 1.26 236\-- 1.59

37\-- .25 87\-- .59 137\-- .93 187\-- 1.26 237\-- 1.60

38\-- .26 88\-- .60 138\-- .93 188\-- 1.27 238\-- 1.61

39\-- .27 89\-- .60 139\-- .94 189\-- 1.28 239\-- 1.61

40\-- .27 90\-- .61 140\-- .95 190\-- 1.28 240\-- 1.62

41\-- .28 91\-- .62 141\-- .95 191\-- 1.29 241\-- 1.63

42\-- .29 92\-- .62 142\-- .96 192\-- 1.30 242\-- 1.63

43\-- .29 93\-- .63 143\-- .97 193\-- 1.30 243\-- 1.64

44\-- .30 94\-- .64 144\-- .97 194\-- 1.31 244\-- 1.65

45\-- .31 95\-- .64 145\-- .98 195\-- 1.32 245\-- 1.65

46\-- .31 96\-- .65 146\-- .99 196\-- 1.32 246\-- 1.66

47\-- .32 97\-- .66 147\-- .99 197\-- 1.33 247\-- 1.67

48\-- .33 98\-- .66 148\-- 1.00 198\-- 1.34 248\-- 1.67

49\-- .33 99\-- .67 149\-- 1.01 199\-- 1.34 249\-- 1.68

50\-- .34 100\-- .68 150\-- 1.01 200\-- 1.35 250\-- 1.69

Purpose: The Primary stream database provides AMBER with a listing of
flash flood prone streams for which AMBER calculates ABR for comparison
with FFG. The ABR output from

![](media/image9.emf){width="2.126388888888889in"
height="1.6979166666666667in"}![](media/image10.emf){width="2.1173611111111112in"
height="1.7069444444444444in"}

Figure 9. Primary stream definition Figure 10. Primary stream definition

as tributaries to a lake or reservoir as subdivisions of a major stream.

AMBER allows the forecaster to determine if the stream is approaching
bankfull (ABR = FFG), significant flash flooding is occurring (ABR \>
FFG+1"), or severe flash flooding is occurring (ABR \> FFG+2").

Contents: The Primary Stream database includes the following elements;

1\. Stream name.

2\. Latitude/Longitude of stream mouth.

3\. Counties containing the stream (up to 4)

4\. Number of subdivisions in this primary stream.

5\. If the stream is gaged, reporting site number of the gage.

6\. Downstream river site number below the mouth of the stream.

7\. AMBER primary stream number.

8\. AMBER MAP number containing this primary stream.

9\. Number of WSR-88D bins in the watershed.

10\. List of AMBER topographic map number containing the watershed.

11\. Area of the watershed in tenths of a square mile.

12\. Length of Stream Thalweg in tenths of miles.

13\. Slope of the stream in feet of fall per 1000 feet.

14\. Minimum and maximum radar azimuth and range of the watershed.

15\. List of the AMBER subdivisions in the watershed.

**3.2.6 SUBDIVISION DATABASE**

Definition: A subdivision of a primary stream is any watershed that is
contained within a primary stream watershed. These may include
tributaries of a primary stream as shown in Figure 11. Subdivisions may
be created by dividing primary streams into upper and lower reaches
(Figure 12). The upper and lower reaches may be divided for any number
of reasons, such as a road crossing , bridge or a population center.

![](media/image11.emf){width="2.595138888888889in"
height="2.46875in"}![](media/image12.emf){width="2.4472222222222224in"
height="2.30625in"}

Figure 11. Subdivision definition as Figure 12. Subdivision definition
as

tributaries of primary stream. upstream-downstream segments.

Subdivisions may be created for road crossings or at the location of a
town as shown in Figure 13. Subdivisions of subdivisions are allowed
with up to three levels of nesting. Figure 14 shows an example of
subdivisions of a subdivision, where the subdivided stream (the parent
stream 5020) is an AMBER subdivision.

![](media/image13.emf){width="2.297222222222222in"
height="2.171527777777778in"}

![](media/image14.emf){width="2.3958333333333335in"
height="2.3194444444444446in"}

Figure 13. Subdivision definition for Figure 14. Subdivision definition
as a city or road crossing. tributaries of another subdivision.

Purpose: The Subdivision database provides AMBER with a listing of flash
flood prone streams. ABR is computed for each subdivision for comparison
with FFG to determine flash flood threat. The ABR output from AMBER
allows the forecaster to determine if the stream is approaching bankfull
(ABR = FFG), if significant (ABR \> FFG+1) or severe (ABR \> FFG+2)
flash flooding is occurring.

Contents: The Subdivision database includes the following elements;

1\. Stream name.

2\. Latitude/Longitude of stream mouth.

3\. Counties containing the stream (up to 4)

4\. Number of subdivisions in this subdivision stream.

5\. If the stream is gaged, reporting site number of the gage.

6\. Parent Stream, i.e., the watershed that is subdivided.

7\. AMBER subdivision stream number.

8\. AMBER MAP number containing this primary stream.

9\. Number of WSR-88D bins in the watershed.

10\. List of AMBER topographic map number containing the watershed.

11\. Area of the watershed in tenths of a square mile.

12\. Length of stream thalweg in tenths of miles.

13\. Slope of the stream in feet of fall per 1000 feet.

14\. Minimum and maximum radar azimuth and range of the watershed.

15\. List of the AMBER subdivisions in this subdivision.

**3.2.7 URBAN AREA - Z/R GAGE DATABASE**

DEFINITION: Many major urban areas reside along major rivers and are not
directly impacted by stream flooding. Heavy rainfall in an urban areas
can produce life threatening conditions as storm drains capacity is
quickly exceeded. To provide guidance to the forecaster for these heavy
bursts of rainfall, AMBER calculates ABR in these urban areas, typically
with areas of 1 to 3 mi^2^.

Figure 15 shows an example of how urban areas might be defined in an
area where primary streams have previously been defined. AMBER will
produce a realistic assessment of flash flood potential when radar
estimates are accurate. The fixed Z/R relation used on the WSR-88D is
not always valid. To determine the performance of the WSR-88D Z/R in
real time, AMBER calculates the radar estimated rainfall at the location
of each rain gage in the NWSFO area of warning responsibility.
![](media/image15.emf){width="2.2875in" height="2.321527777777778in"}

Figure 15. Urban Area Definition.

The radar rain gage estimates may then be compared to real time IFLOWS
data to determine if the Z/R relationship is providing realistic
rainfall estimates.

Each of these rain gage locations are stored in the Urban Area database
as a Z/R gage site with a single WSR-88D 1^o^ x 1km range bin as its
area.

PURPOSE: The urban areas ABR calculation provides the flash flood
forecaster information on heavy rain occurrence in heavily urbanized
areas. The ABR calculated for these small areas might almost be
considered a rain gage reading within the urban area, but is in fact an
average rainfall over the entire urban area.

The Z/R gage calculation provides the flash flood forecaster with a
means of comparing real time rain gage information with real time radar
estimates at the location of the rain gage. The forecaster can then
adjust observed ABR estimate in real time using the rain gage
information.

CONTENT: The urban database includes the following data elements;

1\. Urban area name.

2\. Latitude/Longitude of the center of the urban area.

3\. County containing the urban area (up to 4 counties).

4\. Observing site number for an observer within the urban area.

5\. Type of urban area (1 = urban area; 2 = Z/R gage).

6.  Type of Z/R site (1=IFLOWS, 2=GOES, 3=DARDC, 4=NWS COOP, 5=

SKYWARN, 6=ALERT, 7=LARC, 8=CORPS COOP, 9=ASOS, 0=Urban Area)

7\. AMBER Urban area number (4000 - 4999)

8\. AMBER MAP area containing this urban area.

9\. Number of WSR-88D bins in the urban area. (=1 for all Z/R sites)

10\. List of topographic maps holding the urban area.

11\. Area of the urban area in tenths of a square mile.

12\. Maximum elevation above sea level of urban area.

13\. Minimum elevation above sea level of urban area.

14\. Minimum and maximum radar azimuth and range of urban area.

**3.2.8 OBSERVING SITE DATABASE**

PURPOSE: To provide the AMBER system a listing of all rain gage sites,
river gage sites, stream gages sites, dam or reservoir sites and
temperature sites in the NWSFO area of warning responsibility.

CONTENT: The observing site database includes the following elements;

1\. Name of the site.

2\. Handbook 5 identifier of the site.

3\. Latitude/Longitude of the site to the nearest second.

4.  Data platform type: (1=IFLOWS, 2=GOES, 3=DARDC, 4=NWS COOP,5=

SKYWARN, 6=ALERT, 7=LARC, 8=CORPS COOP, 9=ASOS, 10-98=not in

use, 99=deleted observer)

5\. Radar azimuth of site in tenths of degrees.

6\. Radar range of site in tenths of kilometers.

7\. AMBER topographic map number containing observing site.

8\. Rack and map number of topographic map containing observing site.

9\. Primary stream number containing the observing site.

10\. Subdivision stream number containing the observing site.

11\. MAP number containing the observing site.

12\. Type of sensor at observing site: "yes or no" for rain gage, stream
or river gage, temperature, dewpoint, wind, snow depth, below freezing
rain gage.

13\. Type of GOES sensor, used only for GOES gages. Yes or no for
PP-rainfall accumulation, HG-stream or river gage, TA-air temperature,
HP-pool elevation, HT-tailwater gage, PA-rainfall accumulator.

**3.2.9 TOPOGRAPHIC MAP DATABASE**

PURPOSE: The Topographic Map database provides AMBER with a listing of
all United States Geological Survey 7.5 minute topographic maps in the
230km radius of the radar. These maps are the base source of information
for all of the other AMBER databases. Watershed boundaries of Mean Areal
Precipitation areas, Major Streams, Primary Streams, Subdivisions and
Urban Areas are all hand drawn onto the topographic maps. The location
of the intersection of each 1^o^ radar azimuth with the border of
topographic map and its distance from the radar in tenths of a kilometer
is also noted on the border of each topographic map. These radar azimuth
plots can then be used to generate a database of 1^o^ x 1km radar bins
of the WSR-88D Digital Hybrid Scan Reflectivity (DHR) product in each
stream watershed.

CONTENT: The following elements are contained in the topographic map
database;

1\. Latitude of the southwest corner of the topo map.

2\. Longitude of the southwest corner of the topo map.

3\. Name of the topographic map.

4\. Topographic map master grid reference number. (Figure 1)

5\. Rack and map number of the topographic map.

6\. Counties containing the topographic map (up to 4 counties).

7\. AMBER number of the topographic map.

**3.3 BINS**

The BINS program allows the user to display the contents of the files
containing the WSR-88D 1^o^ x 1km DHR radar grid assignments for each
category of stream watershed. The data can be examined one radar radial
at a time. All stream assignments for each one kilometer grid box along
the single radar radial are displayed.

**3.3.1 WSR-88D 1^o^ x 1km BIN DATABASE**

DEFINITION: The stream watersheds are related to the radar rainfall data
by determining which WSR-88D 1^o^ x 1km range bins reside within each
watershed. One set of radar bin definitions is stored for each AMBER
watershed category; MAP areas, major streams, primary streams, each
layer of subdivisions and urban areas-Z/R gages. The database is stored
in the AMBER subdirectory in files named:

AMBER Category Filename

1\. MAP areas MAPS.AMB

2\. Major streams MAJOR.AMB

3\. Primary streams PRIMARY.AMB

4\. Subdivisions SUBS1.AMB, SUBS2.AMB, AND SUBS3.AMB

5\. Urban-Z/R gages URBAN.AMB

The files with a file extension of AMB, are the AMBER WSR-88D 1^o^ x 1km
database files used by the operational software to produce the average
basin rainfall computations stored in the ABR database. For example, the
operational AMBER software uses PRIMARY.AMB file to compute ABR for the
primary streams.

For each AMBER stream category (PRIMARY, MAPS, MAJOR, URBAN, SUB1, SUB2,
and SUB3) there are three different radar bin files, with different file
extensions. For example, the primary streams category will have three
data files:

PRIMARY.AMB - The operational AMBER file.

PRIMARY.BNS - The data entry AMBER file.

PRIMARY.ASK - The ASCII test file.

The PRIMARY.BNS file is used by the system administrator to store the
initial data into the file, or to make corrections, deletions or
additions to the file. The BNS file is then used to create both the AMB
file and the ASK file. The contents of the BNS file is displayed by the
BINS program.

The PRIMARY.ASK file is a ASCII text version of the operational file.
This file can be examined using any text editor. The ASCII radar bins
files are used to transfer this data from the MS DOS environment to the
UNIX environment.

PURPOSE: The radar bins database provides AMBER with the WSR-88D
information format needed to match each 1km radar bin along each 1^o^
radar azimuth, into each watershed in the AMBER database. The bin
assignment into the watersheds allows the calculation of Average Basin
Rainfall (ABR) in each watershed. Since the area of each range bin is
known, AMBER can estimate the area of each watershed by summing the area
of all bins falling within the watershed.

CONTENT: All radar bins database files have the same structure. Each
file is a string of integer numbers defining the 1km radar bins into
each watershed. The general format for all the bin database files is as
follows:

-1, azimuth, range(km), basin number, range(km), basin number, ... ...
range(km), basin number, -1, azimuth etc.

The -1 is an indicator for the start of a new radar azimuth. The number
following the -1 is the value of the radar azimuth in degrees (0 to
359). The first radar range after the azimuth will always be 1km,
followed by the basin number that contains the 1km bin. Pairs of radar
range and basin number, matching the bins into the watershed, are listed
until the end of the radial is reached (at 230km). Each bins file begins
with the 0^o^ radar azimuth and ends with the 359^o^ azimuth. Each radar
radial begins with the 1km range bin, which is the radar bin from 1 to
2km from the radar with the center of the bin at 1.5km. No calculations
are performed using the range bin from 0 to 1km. The 200^o^ radar
azimuth is the azimuth from 200^o^ to 201^o^, with the azimuth of the
radar radial centered at 200.5^o^.

A string of data for a radar radial of a primary stream might look like
this;

-1 200 1 1250 6 1370 12 0 17 1790 22 0 -1 201 ...

In the example above for the 200^o^ radar azimuth, the numbers that
follow the -1 indicator and the 200^o^ radar azimuth, are pairs of radar
range(km) and stream number. Primary stream 1250 is assigned to the
range bins from 1km to 5km, primary stream 1370 is assigned the bins
from 6 to 11km, the bins from 12 to 16km are not assigned to any stream
(stream number = 0), stream number 1790 is assigned the bins from
17-21km, and no streams are assigned to the rest of the radar radial
from 22 to 230km. The -1 indicates the start of the 201^o^ radar radial.
All radar radials within the file are listed in numerical order from
0^o^ to 359^o^. All radar radials are present in the file, even if no
streams are assigned to the radar radial. If no streams were assigned to
the radar radials from 311^o^ to 314^o^, that portions of the bins file
would appear as the sequence:

... -1 311 -1 312 -1 313 -1 314 -1 315 1 1250 33 1760...

and then the normal range (km), basin pairs would resume at the 315^o^
radial with stream 1250 assigned the bins from 1 to 32km.

The user can print out the ASCII text files of the range bins if a
listing for all radials is desired, or the BINS program can be used to
display a single radial of data from the BNS files for each range bin
category. All of these bin assignments are accomplished by plotting
individual radar radials on 7.5 minute topographic maps, and comparing
those plotted radar radials with the watershed constructed on the
topographic maps.

**3.4 SUMMARY**

The AMBER stream basin database is critical to the performance of AMBER.
The output received from AMBER will only be as good as the information
stored in the database. Errors in radar bin assignments will produce
invalid rainfall estimate. Quality control of the database is
essential!! Detailed information on flash flood stream watersheds is not
generally available to the NWSFO forecaster in an easily digestible
form. The creation of a stream watershed database puts this information
at the forecaster's fingertips and allows rapid and easy access to the
stream information during the warning process.

**Chapter 4.0 THE AMBER AVERAGE BASIN RAINFALL (ABR) DATABASE**

The AMBER real time software, running on a UNIX platform is started by
entering the command rt_amber (enter) in the AMBER directory on the SAC
computer. The real time software was written and is maintained by Paul
Jendrowski, currently the Science and Operations Officer at the NWSFO in
Honolulu, HI. The AMBER real time software computes Average Basin
Rainfall for every radar volume scan by using the WSR-88D radar bins
files in the AMBER stream basin database. ABR is computed for each
category of radar bins files, including all MAP areas, major streams,
primary streams, stream subdivisions and urban areas. All of the
computed ABR data is stored in the Average Basin Rainfall (ABR) database
in the AMBER directory of the SAC computer.

![](media/image16.emf){width="6.129166666666666in"
height="4.115277777777778in"}

Figure 16. Calculation of ABR and ABR Rate for any stream watershed.

The procedure used by the AMBER operational software to compute ABR is
shown in Figure 16. A small imaginary watershed is depicted by a dashed
line. The 1km range bins of the 90^o^ WSR-88D radar radial is plotted on
this watershed. Only those 1km range bins whose center (solid circle)
falls within the watershed are used to compute ABR for the watershed.
Note that the width radar beam is 0.87km at a range of 50km and 0.93km
at 53km. The 50km range bin (centered at 50.5km and 90.5^o^ azimuth) is
0.34mi^2^ in area. The area of each range bin is known and is a function
of radar range. The 51 and 52km bins are both 0.35mi^2^ in area. AMBER
estimates the area of each watershed in the stream basin database by
summing the total area of all radar bins falling within the watershed.
AMBER would estimate the area of this watershed to be 1.04 mi^2^, while
the actual area of the watershed may be closer to 1.4 mi^2^. This method
for estimating watershed area increases in accuracy with increasing
watershed area. The technique is most accurate close to the radar where
the range bin size is small, and less accurate at long ranges from the
radar as the bin size gets relatively large.

The AMBER operational software requires two consecutive DHR products to
produce one rainfall accumulation. The reflectivity in the DHR product
is converted to a rainfall rate at each 1km radar bin. When the next DHR
product is received from the WSR-88D for the next volume scan of the
radar, the rainfall rate is again determined from the reflectivity
product of the new volume scan. When the radar is operating in Volume
Coverage Pattern 21 (VCP21), the normal mode of operation, these volume
scans will be approximately 6 minutes apart. If the radar is operating
in VCP11, the volume scans will be approximately 5 minutes apart. For
each 1km radar bin, the rainfall rate for the current volume scan is
averaged with the rainfall rate from the previous volume scan to
determine the average rainfall rate for the time interval between the
two volume scans. This average rainfall rate is then multiplied by the
time duration between volume scans to determine the amount of rainfall
at each 1km radar bin, that has fallen during the time duration between
the volume scans (usually 5-6 minutes).

The amount of rainfall at each 1km radar bin is then areally averaged
using the above outlined procedure (see Figure 16), to determine the ABR
for each watershed in the AMBER stream watershed database. These short
duration 5-6 minutes values of ABR are then stored in the AMBER ABR
database for all AMBER watershed categories. The operational software
then sums the stored ABR accumulations for the past six hour period,
producing six different time periods of rainfall summations from 15
minutes to 6 hours in duration. These six time periods may be set by the
user to any 5 discrete time periods of 6 hours or less through AMBER
adaptation data. The Pittsburgh NWSFO is currently using time periods of
20, 40, 60, 90, 120, and 180 minutes.

The current Flash Flood Guidance(FFG) for every county in the AMBER
county database is entered into the AMBER real time software once a day,
at approximately 1500 GMT. The FFG is provided by the River Forecast
Center to the NWSFO and contains FFG for the time periods of 1, 3, 6, 12
and 24 hours. AMBER extrapolates values of FFG between these provided
values for comparison with all ABR time durations. For example, if
1-hour FFG is 1.2 inches and 3-hour FFG is 2.0 inches, AMBER would used
a 2-hour FFG of 1.6 inches for comparison with the 120 minute ABR
accumulations. All ABR durations of 1 hour or less are compared to
1-hour FFG. The ABR database also includes the beginning and ending time
of each volume scan in seconds since midnight at 0000 GMT. A detailed
description of the files in the ABR database can be found in Appendix B,
sections B.14 to B.18.

The rainfall data access programs described in Chapter 2 display the
data stored in the ABR database. The rainfall data in the ABR database
is maintained in the hard disk of the SAC computer for a three month
period. After three months, the data is archived to 9mm tape. The ABR
data is available since 1 June 1996 for Pittsburgh. WSD-88D archive-II
tapes can be used to run ABR data in playback mode.

**Chapter 5. CREATION OF THE AMBER DATABASE.**

This is an outline for the AMBER system administrator who is charged
with the construction of the AMBER stream basin database for a NWSFO.
Follow the steps in the outline in order, as the databases created later
in the process will depend on the databases created early in the
process. The stream basin database is created and maintained on an IBM
compatible PC.

Installation: Create a subdirectory named AMBER.

Copy the admin.exe file into the AMBER subdirectory.

Enter the command admin(enter) and this self exploding file will create
all necessary files.

5.1 Modify the STATES.AMB file. A copy of this file will be in the AMBER
subdirectory. Use the NWSFO program to check record number 60 and be
sure the nine AMBER database categories are set to the following values:

Counties = 0 Gage sites = 0

River gages = 0 MAP area = 99

Primary stream = 999 Major stream = 499

Subdivisions = 4999 Urban areas = 3999

Topo quads = 0 NWSFO identifier = xxx

where xxx = the 3 letter identifier for your office.

5.2 Create the COUNTIES.xx files. The xx = the two letter state
identifier. These files contain an alphabetical listing of all counties
for a state, plus the FIPS code for each county, the office of warning
responsibility, and the office of backup warning responsibility. The
information, including an alphabetical listing of the counties may be
found in WSOM C-47. Use the NWSFO program to create these files for any
state within the 230km radius of the WSR-88D. Some of these files may
already exist in the AMBER subdirectory. Print out a copy of the county
listing for the states you need using the NWSFO program. Check these
listings for errors in spelling, FIPS code and offices of warning
responsibility. You will need these county listings to create your AMBER
county database file. Any errors in the COUNTIES.xx file will be
transferred to your AMBER county database file. You can use the ZONE
program to enter zone codes for your counties. AMBER does not use these
zone codes at present, but if you would like to use them for a
programming application, they can be entered into the COUNTIES.xx files.
If you have more than two zones in a county, put the first and last zone
number in the two zone slots provided.

5.3 Create the AMBER county database. Print a hard copy of all the
COUNTIES.xx files for the states within the 230km radius of the WSR-88D.
If you use input from more than 1 WSR-88D, you will need a separate
AMBER database for each radar. You must maintain each AMBER database in
a separate subdirectory. The subdirectories may have any name you
choose. If all the COUNTIES.xx files for your area are not in the AMBER
directory, you must create them using the NWSFO program.

To create the AMBER county database, use the program AMBERFIX. Choose
the county warning database entry. Choose add a county. Choose the
active state. Enter the county number from your state listing for all
desired counties. Enter the counties in numerical order so the counties
will be alphabetical.

5.4 Create the TOPO.AMB file. The NWSFO program creates the TOPO.AMB
file. This file contains the 7.5 minute topographic map master grid. The
topographical master grid allows the automatic entry of the latitude and
longitude of each topographic map entered into the AMBER "topomap"
database. To create the topographical master grid, the minimum and
maximum latitude and longitude that encloses the 230 km radar range of
the WSR-88D is entered into the program (Figure 17). The entry of
minimum and maximum latitude and longitude must be in whole degrees .The
program assigns consecutive grid numbers, starting with "1" for the
northwestern most 7.5 minute grid box, and proceeding east along a
constant latitude. When the minimum longitude is reached along the row
of constant latitude, the numbering resumes on the western border of the
grid at the next constant latitude row of maps to the south. The
numbering continues until all topomaps are assigned a grid number, with
the most southeastern map of the grid assigned the largest grid number.

Figure 18 shows the portion of the Pittsburgh NWSFO topographical master
grid from 40-41^o^ North latitude and 80-81^o^ West longitude. The
topographical master grid numbers are displayed on all "topomaps"
bordering the outside of this 1^o^ latitude-longitude area. Note that
each 1^o^ latitude longitude box contains 64 - 7.5 minute topographic
maps. County boundaries are included on this map to give a sense of
scale. Beaver county in Pennsylvania is 436 mi^2^, Jefferson county in
Ohio is 410 mi^2^, while Hancock county in West Virginia is 84 mi^2^.
One degree of latitude is 60 nm or 111.12 km, while 7.5 minutes of
latitude is 7.5 nm or 13.9 km. The topographic master grid numbers are
used to simplify the data entry of "topomaps" into the AMBER 7.5
topographic map database.

![](media/image18.emf){width="2.3270833333333334in"
height="2.0743055555555556in"}

Figure 17. Setting Minimum and Figure 18. A 1^o^ latitude/longitude

maximum latitude/longitude. segment of the master topographic grid.

Table 2. Output of SEETOPO: The Master Topographic Map Reference Grid.

Minimum/maximum Latitude: 38/43 Minimum/maximum Longitude: 77/83

\*\*\* MASTER GRID REFERENCE \*\*\* PIT FORECAST OFFICE

LATITUDE/LONGITUDE OF SW CORNER OF 7.5 MINUTE TOPOGRAPHIC MAPS

LAT/LON 83.000 82.000 81. 000 80.000 79.000 78.000 77.125 76.000

42.875 1 9 17 25 33 41 48 0

42.750 49 57 65 73 81 89 96 0

42.625 97 105 113 121 129 137 144 0

42.500 145 153 161 169 177 185 192 0

42.375 193 201 209 217 225 233 240 0

42.250 241 249 257 265 273 281 288 0

42.125 289 297 305 313 321 329 336 0

42.000 337 345 353 361 369 377 384 0

41.875 385 393 401 409 417 425 432 0

41.750 433 441 449 457 465 473 480 0

41.625 481 489 497 505 513 521 528 0

41.500 529 537 545 553 561 569 576 0

41.375 577 585 593 601 609 617 624 0

41.250 625 633 641 649 657 665 672 0

41.125 673 681 689 697 705 713 720 0

41.000 721 729 737 745 753 761 768 0

40.875 769 777 785 793 801 809 816 0

40.750 817 825 833 841 849 857 864 0

40.625 865 873 881 889 897 905 912 0

40.500 913 921 929 937 945 953 960 0

40.375 961 969 977 985 993 1001 1008 0

40.250 1009 1017 1025 1033 1041 1049 1056 0

40.125 1057 1065 1073 1081 1089 1097 1104 0

40.000 1105 1113 1121 1129 1137 1145 1152 0

39.875 1153 1161 1169 1177 1185 1193 1200 0

39.750 1201 1209 1217 1225 1233 1241 1248 0

39.625 1249 1257 1265 1273 1281 1289 1296 0

39.500 1297 1305 1313 1321 1329 1337 1344 0

39.375 1345 1353 1361 1369 1377 1385 1392 0

39.250 1393 1401 1409 1417 1425 1433 1440 0

39.125 1441 1449 1457 1465 1473 1481 1488 0

39.000 1489 1497 1505 1513 1521 1529 1536 0

38.875 1537 1545 1553 1561 1569 1577 1584 0

38.750 1585 1593 1601 1609 1617 1625 1632 0

38.625 1633 1641 1649 1657 1665 1673 1680 0

38.500 1681 1689 1697 1705 1713 1721 1728 0

38.375 1729 1737 1745 1753 1761 1769 1776 0

38.250 1777 1785 1793 1801 1809 1817 1824 0

38.125 1825 1833 1841 1849 1857 1865 1872 0

38.000 1873 1881 1889 1897 1905 1913 1920 0

The SEETOPO program can be used to print out a summary of the master
topographic grid number assignments as a function of latitude and
longitude. The SEETOPO listing will be needed to enter maps into the
AMBER topographic map database. Table 2. shows a summary of the master
topographic grid for the Pittsburgh NWSFO as output by the SEETOPO
program.

5.5 Create the AMBER 7.5 minute topographic map database. The USGS
publishes an index of topographic maps by state, at no charge. Call the
USGS at 800-872-6277. Menu choices 1, 1 and 1 will allow you to request
an index for any state needed. On the USGS index map for each state,
write the topographic master grid number on each topographic map you
wish to enter. The latitude-longitude listed by the SEETOPO program for
the master grid reference is the latitude/longitude of the southwest
corner of each topographic map. This master grid number is the number
you must enter into the AMBERFIX program to enter topographic maps into
the AMBER topographic map database.

Begin with the northwestern most topographic map on the USGS index map,
that will be entered into the database. Start the AMBERFIX program and
choose the topographic map database. Choose enter new topographic map.
Begin the data entry procedure by entering the master topographic grid
reference of the northwestern most topographic map. The user must type
in the name of the topographic map, the program will automatically store
the correct latitude and longitude for the topographic map and assign
the "topomap" a record number (starting with 1 for the first map
entered. After the user types in the name of the "topomap", the AMBERFIX
program will automatically increment to the next topographic map to the
east at the same latitude of the last map entered. You enter the name of
the next map, if you wish to include it in the AMBER topomap database,
and continue the process until the end of the current row of maps along
the current latitude is reached. Then you stop data entry, and move to
the western most map in the next row of maps south of the current row.
Enter master grid reference of western most map in the next row of
topomaps south of the previously entered row. Continue this process
until all topomaps are entered into the database.

5.6 Create the AMBER watershed databases. You must have the county
database and topographic map database complete before beginning data
entry into the watershed databases. There are four categories of
watershed databases, Mean Areal Precipitation areas (MAP), Major streams
(those streams \> 200mi^2^ in area), Primary streams and Subdivisions.
Chapter 3 gives a detailed summary of how each type of watershed may be
constructed. A section is devoted to each type: MAP AREAS in section
3.2.3, major streams in section 3.2.4, primary streams in section 3.2.5,
subdivisions in section 3.2.6, and urban areas in section 3.2.7. The
AMBERFIX program is used to enter data into the watershed databases.
Each watershed is assigned a unique number. MAP areas are assigned
number from 100 to 499. Major streams are assigned numbers from 500 to
999, Primary streams area assigned numbers from 1000 to 3999,
subdivisions are assigned numbers from 5000 to 9999, and urban areas
area assigned numbers from 4000 to 4999. When you add a new stream to
any of these categories using the AMBERFIX program, the software finds
the highest watershed number currently used in the database for that
category (stored in STATES.AMB... and displayable with the STATUS
program) and increments it by one. You then enter the name of the
watershed, the counties that contain the watershed, and the topographic
maps that contain the watershed. The AMBERFIX program assigns the
number, so you must start your numbering of all watersheds with the
lowest allowable number for that category, and increment the numbers as
you assign them to the watersheds on the topographic maps.

The watershed ridge-line boundaries must be drawn onto the topographic
maps for each watershed. By convention, the boundaries are drawn in
pencil, and after you are satisfied the boundary is correct, the lines
are color coded with highlighter. Green for the MAP boundaries, pink for
the major stream and primary stream boundaries, and yellow for the first
tier of subdivision boundaries and blue for the second tier of
subdivisions. The number of each watershed is written on the topographic
map in red ink. If the watershed extends over more that one topographic
map, the basin number is written on the border of the map where the
boundary intersects the border. All data for the watershed databases in
entered using the AMBERFIX program.

1.  Enter data into the AMBER MAP database.

5.6.2 Enter data into the AMBER major stream database.

5.6.3 Enter data into the AMBER primary stream database.

5.6.4 Enter data into the AMBER subdivision database.

5.6.5 Enter data into the AMBER urban area database.

5.7 Enter data for each of the watershed databases into the WSR-88D bins
database. Use the RAINGRID program to calculate the intersection of each
WSR-88D radar azimuth with the border of each topographic map in the
AMBER topographic map database. Plot these intersections on the 7.5
minute topographic maps. The SCALE program will calculate 5 second
increments for the plotting scale. Measure the physical distance of 2.5
degrees of longitude, along a latitude line, in centimeters. Enter this
value into the scale program, and the program will output the number of
centimeters at each 5 seconds of longitude. Make the scale markings on
an 8 ½ x 11 inch sheet of paper to allow for easy plotting of the output
from RAINGRID. You will need to make a scale for about every 15 minutes
of latitude. Only one scale is needed along the longitude lines, as the
distance in kilometers along the longitude lines is constant. Measure
2.5 minutes of latitude along a longitude line in centimeters. Enter
this value into the scale program to create a single plotting scale for
latitude.

Each radar azimuth will have an entry point and exit point from each
topographic map. The one map that is an exception in the topographic map
that contains the location of the WSR-88D. This map will have 360 exit
points and no entry points for each radar radial. Figure 19 shows the
Canonsburg topographic map with the borders of the primary streams. Two
radar radials are plotted, 180^o^ and 170^o^ , showing the 1km range
bins. The azimuth intersection calculated by RAINGRID is the 180.5^o^
azimuth for the 180^o^ radial which extends from 180^o^ to 181^o^. One
radar bin is assigned to one and only one watershed per watershed
category. The watershed that contains the center point of the bin is
assigned that bin. The bin at 180^o^ and 18km is assigned to the
watershed that contains the bin center point location at 180.5^o^ and
18.5km. The bin assignment procedure is completed for each category of
watersheds (MAP, primary streams, first layer of subdivisions, second
layer of subdivision, third layer of subdivisions, major streams and
urban areas). In Figure 19, stream number 1640 would be assigned the
range bins from 18 km to 25 km along the 180^o^ radar azimuth, while
stream 1645 would be assigned 26 to 28km.

![](media/image19.emf){width="4.085416666666666in"
height="4.793055555555555in"}

Figure 19. WSR-88D range bin assignments in the Canonsburg topo map.

The BINFIX program is used to store the bin assignments in their
respective files. The BINFIX program stores the initial data entry in a
file with an extension BNS. BINFIX may then be used to create the same
data files with an AMB extension for the operational AMBER file, and the
ASK extension, which is a text file that can be examined with a text
editor. The BINS program

allows the user to examine the contents of the BNS files for any radar
azimuth.

**6.0 REFERENCES**

Davis, R. S., and T. Rossi, 1985: A Scheme for Flash Flood Forecasting
using RADAP-II and

ICRAD. *Preprints, 6^th^ Conference on Hydrometeorology,* Amer. Meteor.
Soc., 107-111.

Davis, R. S., and T. Drake, 1988: The Operational Effectiveness of
RADAP-II During the 1987

Severe Weather Season in Western Pennsylvania. *Preprints, 15^th^
Conference on Severe Local*

*Storms*, Amer. Meteor. Soc., 194-197.

Davis, R. S., 1993: AMBER, A Prototype Flash Flood Warning System.
*Preprints*, *13^th^*

*Conference on Weather Analysis and Forecasting,* Amer. Meteor. Soc.,
379-383.

Davis, R. S., and P. A. Jendrowski, 1996: The Operational Areal Mean
Basin Estimated Rainfall

(AMBER) Module. *Preprints, 15^th^ Conf. on Weather Analysis and
Forecasting*, Amer.

Meteor. Soc., 332-335.

Davis, R. S., 1997: The Integration of the Areal Mean Basin Estimated
Rainfall (AMBER) Flash

Flood Warning System with Automated Rain Gage Data. *Preprints, 1^st^
Symp. on Integrated*

*Observing Systems*, Amer. Meteor. Soc., xxx-xxx.

Saffle, R. E., 1976: D/RADEX products and field operation*. Preprints,
17^th^ Conf. on Radar*

*Meteorology*, Amer. Meteor. Soc., 555-559.

Saffle, R. E., and D. R. Greene, 1978: The Role of Radar in the Flash
Flood Watch Warning

System: Johnstown Examined. *Preprints 18^th^ Conference on Radar
Meteorology*, Amer.

Meteor. Soc., 468-473.

Saffle, R. E., 1987: Radar Rainfall Estimates for the Pittsburgh Little
Pine Creek Flash Flood of

May 1986. *Preprints, 15^th^ Conf. on Severe Local Storms*, Amer. Meteo.
Soc., 198-200.

Sweeney, T. L., 1991: Modernized Areal Flash Flood Guidance, *NOAA
Technical Memorandum*

*44*, Office of Hydrology, 1-17.

**Appendix A . AMBER MSDOS PROGRAM SUMMARY**

**A1. AMBER:** Allows the user to display contents of the AMBER stream
watershed database, excluding the WSR-88D bin database which is
displayed by the BINS program This program also allows the user to print
the contents of the database.

**A2. AMBERFIX:** Allows the system administrator to create, modify or
delete database items from the AMBER watershed database. This program
also performs all functions of the AMBER program, allowing the display
and printing of all data.

**A3. ANNULUS:** Prints a listing of the "area in square miles" of each
WSR-88D range bin as a function of range in kilometers.

**A4. AREABINS:** Computes the basin area in square miles for each MAP
area, major stream, primary stream, subdivision and urban area, and
stores the basin area in the AMBER database. The watershed area is
estimated by summing all the WSR-88D bin areas assigned to each
watershed.

**A5. ASKII:** Converts all direct access files in the AMBER DOS
watershed database to an ASCII versions of those files for transfer to a
UNIX based computer.

**A6. AZRAN:** Computes the radar azimuth and range from the WSR-88D
given user input of target latitude and longitude.

**A7. BINFIX:** Allows the system administrator to create, display and
modify the WSR-88D radar bin designation files. This program also
creates ASCII and operational versions of the radar bin designation
files for each category of WSR-88D radar bin designation files including
primary streams, subdivisions, major streams, MAP areas and urban areas.

**A8. BINS:** Allows the user to display the contents of the WSR-88D
radar bin designation files for all AMBER categories including primary
streams, subdivisions, MAP areas, major streams, and urban areas.

**A9. CNTBASIN:** Prints a listing of all primary streams in a county
given the user input of an AMBER county number.

**A10. CNTYSITE:** Displays a listing of all AMBER observing sites in a
county given user input of an AMBER county number.

**A11. DIZZY:** prints a listing of the true radar azimuth corresponding
to the radar azimuth used by the WSR-88D clutter suppression algorithm
as display at the User Control Position (UCP) of the WSR-88D. The
clutter suppression algorithm uses an azimuth from 0 to 256 which
corresponds to the actual radar azimuth of 0 to 360 degrees.

**A12. DSTREAM:** Displays a summary of geographic and hydrologic data
for any stream in the AMBER stream basin database given user input of an
AMBER stream number.

**A13. GETBASIN:** Given user input of WSR-88D azimuth and range
displayed at the PUP, the program displays the primary stream and
subdivisions containing that point.

**A14. HANDY:** Given user input of the Handbook 5 identifier or the
AMBER observing site number, the program displays the data stored about
that observing site.

**A15. HOUR:** Given user input of the number of seconds since midnight,
the program computes the GMT time in hours and minutes. The AMBER
database stores the beginning and ending time of all periods of rainfall
as seconds since midnight. This information is stored in the AMBER ABR
database.

**A16. JD88D:** Given the WSR-88D Julian date, where the WSR-88D Julian
day = 1 is defined as 01JAN1970, the program converts the WSR-88D Julian
day to a month, day, year format. The hybrid scan rainfall files all
reference the date of the product using the WSR-88D Julian date.

**A17. MAKEBINS:** Creates files containing the number of WSR-88D range
bins in each stream watershed, MAP area and urban area. The files
created by the program are given by the filenames:

PRIBINS.AMB, PRIBINS.ASK, URBBINS.AMB, URBBINS.ASK, SUBBINS.AMB,
SUBBINS.ASK where the files ending in AMB are direct access files used
by some of the quality control programs in this listing, and the files
ending in ASK are ASCII files for transfer to a UNIX platform.

**A18. NWSFO:** used by the system administrator to modify the AMBER
control file, STATES.AMB. This program also is used to create the
TOPO.AMB file, which is the master

topographic map grid reference. The program also creates and modifies
the county data files named "COUNTIES.xx", WHERE xx = the two letter
identifier for the state. These county files contain an alphabetical
listing of counties for each state, and are used by the AMBERFIX program
to create the AMBER County database file.

**A19. PRNSITE:** Prints a listing of all AMBER observing sites in a
county, given user input of an AMBER county number.

**A20. QC1:** Quality control test #1: Checks the radar bin designation
files to insure that each radar radial ends with a zero, as required by
the AMBER operational software.

**A21. QC2:** Quality control test #2: Checks the range bin designation
files to insure that range increases along each radar radial, as
required by the AMBER operational software.

**A22. QC3:** Quality control test #3: Checks the PRIBIN, SUBBIN,
URBBIN.AMB files to insure that all watersheds in the stream database
have at least 1 radar bin assigned to them.

**A23. QC4:** Quality control test #4: Checks all radar range bin
designation files to insure that no invalid stream numbers are stored in
these files.

**A24. QC5:** Quality control test #5: Compares the range bin
designation files for primary vs. subdivison1, subdivison1 vs.
subdivision2, MAP vs. primary, and MAP vs. major streams. Each range bin
is checked to insure that the subdivision assigned to that radar bin is
a tributary of the parent stream listed for that range bin. A
discrepancy report is printed so that corrections can be made.

**A25. QC6:** Quality control test #6: The range bin designation files
are checked to insure that no radar azimuth gaps exist within a defined
watershed.

**A26. QC7:** Quality control test #7: Checks the AMBER reporting
station database to insure that no Handbook 5 identifier is repeated
within the database.

**A27. QC8:** Quality control test #8: Checks the AMBER topographic map
database to insure that the list of counties stored for each topographic
map is correct.

**A28. QC9:** Quality control test #9: Checks the AMBER primary stream
and AMBER subdivision database to insure that the subdivision data base
has the correct parent stream listed, and that the primary stream
database has the correct subdivisions listed if the primary is
subdivided. .

**A29. QUAD:** Creates the file "QUAD.AMB", using input from the master
topographic map grid reference and the WSR-88D latitude/longitude stored
in the \"STATES.AMB\" file. The QUAD.AMB file contains the topographic
map number containing each 1-nautical mile range interval along each one
degree of radar azimuth. This data file is used by the \"GETBASIN\"
program to determine which topographic map contains the input target
point entered into "GETBASIN".

**A30. RAINGRID:** Computes and prints all intersections of each 1^o^
WSR-88D radar radial traversing the border of a selected topographic map
in the AMBER topographic map database. The user selects the topographic
map by entering the AMBER topographic map number .

**A31. RING:** Computes the radar range interval of the ring of melting
level contamination given user input of the radar height above sea
level, elevation angle and height of the freezing level.

**A32. SCALE:** Computes the distance in centimeters of 5 second
intervals over a 2 minute length of a latitude circle on a 7.5 minute
topographic map. The user inputs the length in centimeters of a 1.5
minute arc of latitude. These scale measurements can then be plotted on
an

8 ½ by 11 inch sheet of paper, and can be used as a plotting guide for
the output from the RAINGRID program.

**A33. SEETOPO:** Displays the contents of the \"TOPO.AMB\" file created
by the "NWSFO\" program.

**A34. SITETOPO:** Given the input of latitude/longitude stored for each
observing site stored in the AMBER observing site database, the program
determines which topographic map, primary stream and stream subdivisions
contains the observing site. This information is then stored in the
AMBER observing site database.

**A35. STATIONS:** Given the user input of an AMBER stream number, the
program will display all observing sites that fall within that
watershed.

**A36. STATUS:** Displays the contents of the AMBER control file
"STATES.AMB", prints listings of the contents of each COUNTIES.xx file,
and prints a summary of the master topographic map grid reference file.

**A37. ZONES:** Enters the zone forecast FIPS code into the COUNTIES.xx
files.

**A38. ZR:** Computes the radar rainfall rate from input of dBZ for a
user selected Z/R rate.

**Appendix B. AMBER PROGRAMMER\'S REFERENCE**

**B.1 The County Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx1.AMB ‑‑‑ COUNTIES RECL =128 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID COUNTY NUMBERS (1 TO 32767)

RECORD NUMBER: IREC = COUNTY NUMBER

DIRECT ACCESS READ:

READ(1,REC=IREC)CNAME,CFIPS,CSTATE,CWARN,NWSFO,ZONE

WHERE,

CNAME = COUNTY NAME CHAR\*20

CFIPS = COUNTY FIPS CODE (PAC011) CHAR\*6

CSTATE = TWO LETTER STATE ID CHAR\*2

CWARN(1) = OFFICE OF PRIMARY WARNING RESPONSIBILITY CHAR\*3

CWARN(2) = BACKUP OFFICE OF WARNING RESPONSIBILITY CHAR\*3

NSWFO(1) = STATE NUMBER IN THE STATES.AMB FILE I\*2

NWSFO(2) = COUNTY NUMBER IN THE COUNTIES.xx FILE I\*2

ZONE(1) = 1ST ZONE CODE FOR THE COUNTY (PAZ001) CHAR\*6

ZONE(2) = 2ND ZONE CODE FOR THE COUNTY (PAZ002) CHAR\*6

**B.2 The River Observing Site Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx2.AMB FILE ‑‑‑ RIVER STAGE RECL = 128**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID RIVER STAGE NUMBERS (1 TO 32767)

RECORD NUMBER: IREC = RIVER STAGE NUMBER

DIRECT ACCESS READ:

READ(2,REC=IREC)FPOINT,STAGE,RDATA,RNAME

WHERE,

FPOINT = NAME OF FORECAST POINT CHAR\*20

ARRAY STAGE(7) REAL\*4

FORECAST POINT DAM SITE

STAGE(1) = FLOOD STAGE SPILLWAY ELEVATION

STAGE(2) = E‑19 ALERT STAGE MIN SUMMER POOL

STAGE(3) = E‑19 ALERT STAGE MAX SUMMER POOL

STAGE(4) = E‑19 ALERT STAGE MIN WINTER POOL

STAGE(5) = E‑19 ALERT STAGE MAX WINTER POOL

STAGE(6) = E‑19 ALERT STAGE

STAGE(7) = RIVER MILE RIVER MILE

ARRAY RDATA(6) INTEGER\*2

RDATA (1) = SITE NUMBER IN BASN6.xxx (REPORTING SITE DATABASE)

RDATA (2) = DOWNSTREAM RIVER SITE NUMBER

RDATA (3) = TYPE OF STAGE SITE

1 = DAILY FORECAST POINT

2 = NON‑DAILY FORECAST POINT

3 = NON‑FORECAST STAGE POINT

4 = DAM/RESERVOIR

RDATA (4) = MAP CONTAINING FORECAST POINT/DAM

RDATA (5) = UPSTREAM RIVER SITE NUMBER

RDATA (6) = RIVER NUMBER

RNAME CHARACTER\*30 = RIVER NAME

**B.3 The Primary Stream Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx3.AMB ‑‑ PRIMARY STREAMS RECL = 176**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID PRIMARY STREAM NUMBERS (1000 TO 3999)

RECORD NUMBER: IREC = PRIMARY STREAM NUMBER - 999

DIRECT ACCESS READ:

READ(1,REC=IREC)PNAME,PDATA,TOPO,HYDRO,SUBS

WHERE,

PNAME = PRIMARY STREAM NAME CHAR\*30

ARRAY PDATA(16) INTEGER\*2

PDATA (1) = LATITUDE OF STREAM MOUTH (DEGREES)

PDATA (2) (MINUTES)

PDATA (3) (SECONDS)

PDATA (4) = LONGITUDE OF STREAM MOUTH (DEGREES)

PDATA (5) (MINUTES)

PDATA (6) (SECONDS)

PDATA (7) = COUNTY NUMBER #1 CONTAINING STREAM BASIN

PDATA (8) = COUNTY NUMBER #2

PDATA (9) = COUNTY NUMBER #3 ZEROS FILL IN UNUSED SLOTS

PDATA(10) = COUNTY NUMBER #4

PDATA(11) = NUMBER OF SUBDIVISIONS

PDATA(12) = GAGE SITE ON THE PRIMARY STREAM

PDATA(13) = DOWNSTREAM RIVER GAGE NUMBER

PDATA(14) = STREAM NUMBER (1000 TO 3999) = 999 + RECORD NUMBER

PDATA(15) = MEAN AREAL PRECIPITATION BASIN NUMBER

PDATA(16) = NUMBER OF WSR‑88D 1‑DEGREE x 1‑km RANGE BINS

ARRAY TOPO(20) INTEGER\*2

TOPO(1 ‑ 20)HOLDS THE NUMBER OF THE 7.5 MINUTE TOPOGRAPHIC

QUADRANGLES CONTAINING THE PRIMARY STREAM BASIN

HYDRO(7) INTEGER\*2

HYDRO (1) = AREA OF BASIN (IN TENTHS OF SQUARE MILES)

HYDRO (2) = STREAM THALWEG (IN TENTHS OF A MILE)

HYDRO (3) = STREAM SLOPE (FEET OF FALL IN 1000 FOOT LENGTH)

HYDRO (4) = MINIMUM RADAR AZIMUTH IN DEGREES

HYDRO (5) = MAXIMUM RADAR AZIMUTH IN DEGREES

HYDRO (6) = MINIMUM RADAR RANGE IN KILOMETERS

HYDRO (7) = MAXIMUM RADAR RANGE IN KILOMETERS

ARRAY SUBS(30) INTEGER\*2

SUBS(1‑30) CONTAINS THE STREAM NUMBER OF ALL SUBDIVISIONS FOR

THIS PRIMARY STREAM

**B.4 The Stream Subdivision Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx4.AMB ‑‑ SUBDIVISIONS RECL = 176**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID STREAM SUBDIVISION NUMBERS (5000 TO 9999)

RECORD NUMBER IREC = SUBDIVISION NUMBER - 4999

DIRECT ACCESS READ:

READ(4,REC=IREC)SNAME,SDATA,TOPO,HYDRO,SUBS

WHERE,

SNAME = SUBDIVISION STREAM NAME CHAR\*30

ARRAY SDATA(16) INTEGER\*2

SDATA (1) = LATITUDE OF STREAM MOUTH (DEGREES)

SDATA (2) (MINUTES)

SDATA (3) (SECONDS)

SDATA (4) = LONGITUDE OF STREAM MOUTH (DEGREES)

SDATA (5) (MINUTES)

SDATA (6) (SECONDS)

SDATA (7) = COUNTY NUMBER #1 CONTAINING STREAM BASIN

SDATA (8) = COUNTY NUMBER #2

SDATA (9) = COUNTY NUMBER #3 ZEROS FILL IN THE UNUSED SLOTS

SDATA(10) = COUNTY NUMBER #4

SDATA(11) = NUMBER OF SUBDIVISIONS

SDATA(12) = GAGE SITE ON THE STREAM SUBDIVISION

SDATA(13) = PRIMARY STREAM NUMBER OR SUBDIVISION NUMBER

CONTAINING THE SUBDIVISION

SDATA(14) = SUBDIVISION STREAM NUMBER (5000 TO 9999)

STREAM NUMBER = 4999 + RECORD NUMBER

SDATA(15) = MEAN AREAL PRECIPITATION BASIN NUMBER

SDATA(16) = NUMBER OF WSR‑88D 1‑DEGREE x 1‑km RANGE BINS

ARRAY TOPO(20) INTEGER\*2

TOPO(1 ‑ 20) CONTAINS THE NUMBERS OF THE 7.5 MINUTE

TOPOGRAPHIC QUADRANGLES CONTAINING THE

SUBDIVISION\...ZEROS FILL UNUSED SLOTS

ARRAY HYDRO(7) INTEGER\*2

HYDRO (1) = AREA OF BASIN (IN TENTHS OF SQUARE MILES)

HYDRO (2) = STREAM THALWEG (IN TENTHS OF A MILE)

HYDRO (3) = STREAM SLOPE (FEET OF FALL IN 1000 FOOT LENGTH)

HYDRO (4) = MINIMUM RADAR AZIMUTH IN DEGREES

HYDRO (5) = MAXIMUM RADAR AZIMUTH IN DEGREES

HYDRO (6) = MINIMUM RADAR RANGE IN KILOMETERS

HYDRO (7) = MAXIMUM RADAR RANGE IN KILOMETERS

ARRAY SUBS(30) INTEGER\*2

SUBS(1‑30) = NUMBER OF SUBDIVISIONS IN THE SUBDIVIDED STREAM

**B.5 The Topographic Map Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx5.AMB ‑‑‑ TOPO MAPS RECL = 128**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID TOPOGRAPHIC MAP NUMBERS (1 TO 32767)

RECORD NUMBER = TOPOGRAPHIC MAP NUMBER

DIRECT ACCESS READ:

READ(5,REC=IREC)QLAT,QLON,QNAME,QDATA

WHERE,

QLAT = LATITUDE OF SOUTHWEST CORNER OF TOPO QUADRANGLE REAL\*4

QLON = LONGITUDE OF SOUTHWEST CORNER OF TOPO QUADRANGLE REAL\*4

QNAME = NAME OF QUADRANGLE CHARACTER\*30

ARRAY QDATA(8) INTEGER\*2

QDATA(1) = GRID REFERENCE NUMBER OF QUADRANGLE

QDATA(2) = RACK NUMBER OF QUADRANGLE

QDATA(3) = MAP NUMBER ON RACK OF QUADRANGLE

QDATA(4) = COUNTY #1

QDATA(5) = COUNTY #2

QDATA(6) = COUNTY #3

QDATA(7) = COUNTY #4

QDATA(8) = DIGITIZING STATUS

**B.6 The Observing Site Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx6.AMB ‑‑ OBSERVING SITES RECL=128**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID OBSERVING SITE NUMBERS (1 TO 32767)

RECORD NUMBER: IREC = OBSERVING SITE NUMBER

DIRECT ACCESS READ:

READ(6,REC=IREC)ONAME,HAND5,ODATA,OTYPE,OGOES

WHERE,

ONAME = NAME OF OBSERVING SITE CHAR\*20

HAND5 = NWS LOCATION IDENTIFIER CHAR\*5

ARRAY ODATA(20) INTEGER\*2

ODATA(1) = LATITUDE OF OBSERVING SITE ‑ (DEGREES)

ODATA(2) (MINUTES)

ODATA(3) (SECONDS)

ODATA(4) = LONGITUDE OF OBSERVING SITE ‑ (DEGREES)

ODATA(5) (MINUTES)

ODATA(6) (SECONDS)

ODATA(7) = COUNTY NUMBER OF OBSERVING SITE

ODATA(8) = DATA TYPE

1 ‑‑ IFLOWS

2 \-- GOES DCP

3 ‑‑ DARDC

4 ‑‑ NWS COOP OBSERVER

5 ‑‑ SKYWARN OBSERVER

6 ‑‑ ALERT

7 ‑‑ LARC

8 ‑‑ CORP COOP OBSERVER

9 ‑‑ ASOS

10 ‑‑ OPEN

99 ‑‑ THIS OBSERVER DELETED FROM LIST

ODATA(9) = DIGITIZING STATUS

ODATA(10) = RADAR AZIMUTH OF OBSERVING SITE (TENTHS OF A

DEGREE)

ODATA(11) = RADAR RANGE OF OBSERVING SITE (TENTHS OF A

KILOMETER)

ODATA(12) = AMBER TOPOGRAPHIC MAP NUMBER OF OBSERVING SITE

ODATA(13) = RACK NUMBER OF TOPOGRAPHIC MAP

ODATA(14) = MAP NUMBER OF TOPOGRAPHIC MAP

ODATA(15) = PRIMARY STREAM NUMBER (ZERO IF NO PRIMARY STREAM)

ODATA(16) = SUBDIVISION 1 (ZERO IF NO SUBDIVISION 1)

ODATA(17) = SUBDIVISION 2 (ZERO IF NO SUBDIVISION 2)

ODATA(18) = SUBDIVISION 3 (ZERO IF NO SUBDIVISION 3)

ODATA(19) = SUBDIVISION 4 (ZERO IF NO SUBDIVISION 4)

ODATA(20) = MEAN AREAL PRECIPITATION NUMBER

ARRAY OTYPE (10) CHARACTER\*1

OTYPE(1) = RAINGAGE (Y=YES N=NO)

OTYPE(2) = STREAM OR RIVER GAGE (Y=YES N=NO)

OTYPE(3) = TEMPERATURE (Y=YES N=NO)

OTYPE(4) = DEWPOINT (Y=YES N=NO)

OTYPE(5) = WIND (Y=YES N=NO)

OTYPE(6) = SNOW DEPTH (Y=YES N=NO)

OTYPE(7) = BELOW FREEZING RAIN GAGE (Y=YES N=NO)

OTYPE(8-10) USER DEFINED

ARRAY OGOES(10) INTEGER\*2

OGOES(1) = PP - ONE HOUR PRECIPITATION

OGOES(2) = HG - RIVER STAGE OR STREAM STAGE

OGOES(3) = TA - AIR TEMPERATURE

OGOES(4) = HP - POOL ELEVATION OR UPPER STAGE

OGOES(5) = HT - TAIL WATER OR LOWER STAGE

OGOES(6) = PA - RAINFALL ACCUMULATOR

OGOES(7-10) UNUSED

**B.7 The Mean Areal Precipitation Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx7.AMB ‑‑ M.A.P.AREAS RECL = 128 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID MEAN AREAL PRECIPITATION AREA (M.A.P.) NUMBERS (100 TO 499)

RECORD NUMBER: IREC = M.A.P. NUMBER -99

DIRECT ACCESS READ:

READ(7,REC=IREC)MNAME,QPF,RRM,MDATA,HYDRO,SUBMAP

WHERE,

MNAME CHARACTER\*5 NAME OF M.A.P. AREA RECL = 128 bytes

QPF CHARACTER\*5 NAME OF QPF AREA

RRM CHARACTER\*9 AFOS ID OF RRM PRODUCT

ARRAY MDATA(26) INTEGER\*2

MDATA (1) = LATITUDE OF OUTFLOW POINT (DEGREES)

MDATA (2) (MINUTES)

MDATA (3) (SECONDS)

MDATA (4) = LONGITUDE OF OUTFLOW POINT (DEGREES)

MDATA (5) (MINUTES)

MDATA (6) (SECONDS)

MDATA (7) = NUMBER OF NEXT DOWNSTREAM M.A.P. AREA

MDATA (8) = COUNTY #1 COUNTIES CONTAINING M.A.P. AREA

MDATA (9) = COUNTY #2

MDATA(10) = COUNTY #3 ZEROS FILL UNUSED SLOTS

MDATA(11) = COUNTY #4

MDATA(12) = COUNTY #5

MDATA(13) = COUNTY #6

MDATA(14) = COUNTY #7

MDATA(15) = COUNTY #8

MDATA(16) = FORECAST POINT #1 OUTFLOW FORECAST POINT

MDATA(17) = FORECAST POINT #2 ADDITIONAL FORECAST POINTS IN

UPSTREAM

MDATA(18) = FORECAST POINT #3 ORDER\...UNUSED SLOTS CONTAIN

ZEROS

MDATA(19) = FORECAST POINT #4

MDATA(20) = INFLOW M.A.P. #1

MDATA(21) = INFLOW M.A.P. #2

MDATA(22) = INFLOW M.A.P. #3

MDATA(23) = INFLOW M.A.P. #4

MDATA(24) = TOPOGRAPHIC QUAD OF OUTFLOW POINT

MDATA(25) = NUMBER OF 88D 1 DEG X 1MI RANGE BINS FALLING IN

THE M.A.P.

MDATA(26) = M.A.P. NUMBER (100 TO 499) = 99 + RECORD NUMBER

ARRAY HYDRO(7) INTEGER \*2

HYDRO(1) = AREA OF M.A.P AREA (TENTHS OF A SQUARE MILE)

HYDRO(2) = LENGTH OF THALWEG (TENTHS OF A MILE)

HYDRO(3) = SLOPE OF THALWEG (FEET OF DROP PER MILE)

HYDRO(4) = MINIMUM RADAR AZIMUTH IN DEGREES

HYDRO(5) = MAXIMUM RADAR AZIMUTH IN DEGREES

HYDRO(6) = MINIMUM RADAR RANGE IN KILOMETERS

HYDRO(7) = MAXIMUM RADAR RANGE IN KILOMETERS

ARRAY SUBMAP(4) CHARACTER\*8 NAME OF M.A.P. SUBDIVISIONS

**B8. Major Stream Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\*\* FILE STRUCTURE OF xxx8.AMB ‑‑ MAJOR STREAMS RECL= 216
BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID MAJOR STREAM NUMBERS (500 TO 999)

RECORD NUMBER: IREC = MAJOR STREAM NUMBER -499

DIRECT ACCESS READ:

READ(8,REC=IREC)PNAME,PDATA,TOPO,HYDRO,PRIME

WHERE,

PNAME = MAJOR STREAM NAME CHAR\*30

ARRAY PDATA(16) INTEGER\* 2

PDATA (1) = LATITUDE OF STREAM MOUTH (DEGREES)

PDATA (2) (MINUTES)

PDATA (3) (SECONDS)

PDATA (4) = LONGITUDE OF STREAM MOUTH (DEGREES)

PDATA (5) (MINUTES)

PDATA (6) (SECONDS)

PDATA (7) = COUNTY NUMBER #1 CONTAINING STREAM BASIN

PDATA (8) = COUNTY NUMBER #2

PDATA (9) = COUNTY NUMBER #3 ZEROS FILL IN UNUSED SLOTS

PDATA(10) = COUNTY NUMBER #4

PDATA(11) = NUMBER OF PRIMARY STREAMS

PDATA(12) = GAGE SITE NUMBER ON THIS MAJOR STREAM

PDATA(13) = DOWNSTREAM RIVER GAGE NUMBER

PDATA(14) = STREAM NUMBER (500 TO 999) = 499 + RECORD NUMBER

PDATA(15) = MEAN AREAL PRECIPITATION BASIN NUMBER

PDATA(16) = NUMBER OF WSR‑88D 1‑DEGREE x 1‑km RANGE BINS

ARRAY TOPO(20) INTEGER\*2

TOPO(1 ‑ 20) CONTAINS THE NUMBERS OF THE 7.5 MINUTE TOPOGRAPHIC

QUADRANGLES CONTAINING THE SUBDIVISION\...ZEROS

FILL UNUSED SLOTS

ARRAY HYDRO(7) INTEGER\*2

HYDRO (1) = AREA OF BASIN (IN TENTHS OF SQUARE MILES)

HYDRO (2) = STREAM THALWEG (IN TENTHS OF A MILE)

HYDRO (3) = STREAM SLOPE (FEET OF FALL IN 1000 FOOT LENGTH)

HYDRO (4) = MINIMUM RADAR AZIMUTH IN DEGREES

HYDRO (5) = MAXIMUM RADAR AZIMUTH IN DEGREES

HYDRO (6) = MINIMUM RADAR RANGE IN KILOMETERS

HYDRO (7) = MAXIMUM RADAR RANGE IN KILOMETERS

ARRAY PRIME(50) INTEGER\*2

PRIME (1‑50) PRIMARY STREAMS CONTAINED IN THIS MAJOR STREAM.

**B.9 The Urban Area - Z/R Gage Database**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**\*\*\*\* FILE STRUCTURE OF xxx9.AMB ‑‑ URBAN AREAS RECL = 128**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

VALID URBAN AREA (4000 TO 4999)

RECORD NUMBER: IREC = URBAN AREA NUMBER -3999

DIRECT ACCESS READ:

READ(9,REC=IREC)PNAME,PDATA,TOPO,HYDRO

WHERE,

PNAME = URBAN AREA NAME CHAR\*30

ARRAY PDATA(16) INTEGER\*2

PDATA (1) = LATITUDE OF URBAN AREA (DEGREES) CENTER OF

PDATA (2) (MINUTES) URBAN AREA

PDATA (3) (SECONDS)

PDATA (4) = LONGITUDE OF URBAN AREA (DEGREES)

PDATA (5) (MINUTES)

PDATA (6) (SECONDS)

PDATA (7) = COUNTY NUMBER #1 CONTAINING URBAN AREA

PDATA (8) = COUNTY NUMBER #2

PDATA (9) = COUNTY NUMBER #3 ZEROS FILL IN UNUSED SLOTS

PDATA(10) = COUNTY NUMBER #4

PDATA(11) = REPORTING SITE DATABASE \#

PDATA(12) = TYPE OF SITE (1=URBAN AREA, 2=Z/R SITE)

PDATA(13) = TYPE OF GAGE, ZERO IF PDATA(12) = 1

1 = IFLOWS

2 = GOES DCP

3 = DARDC

4 = NWS COOP

5 = SKYWARN

6 = ALERT

7 = LARC

8 = CORPS COOP

9 = ASOS

10-98 UNDEFINED

99 = DELETED OBSERVING SITE

PDATA(14) = URBAN AREA NUMBER = 3999 + RECORD NUMBER

PDATA(15) = MEAN AREAL PRECIPITATION BASIN NUMBER

PDATA(16) = NUMBER OF WSR‑88D 1‑DEGREE x 1‑km RANGE BINS

ARRAY TOPO(20) INTEGER\*2

TOPO(1 ‑ 20)HOLDS THE NUMBER OF THE 7.5 MINUTE TOPOGRAPHIC

QUADRANGLES CONTAINING THE URBAN AREA

ARRAY HYDRO(7) INTEGER\*2

HYDRO (1) = AREA OF URBAN AREA (IN TENTHS OF SQUARE MILES)

HYDRO (2) = MAXIMUM ELEVATION (FEET)

HYDRO (3) = MINIMUM ELEVATION (FEET)

HYDRO (4) = MINIMUM RADAR AZIMUTH IN DEGREES

HYDRO (5) = MAXIMUM RADAR AZIMUTH IN DEGREES

HYDRO (6) = MINIMUM RADAR RANGE IN KILOMETERS

HYDRO (7) = MAXIMUM RADAR RANGE IN KILOMETERS

**B.10 WSR-88D 1o x 1km Bin Designation Files**

**B.10.1 Data Entry Files:**

PRIMARY.BNS - PRIMARY STREAMS

SUBS1.BNS - 1ST TIER OF STREAM SUBDIVISIONS

SUBS2.BNS - 2ND TIER OF STREAM SUBDIVISIONS

SUBS3.BNS - 3RD TIER OF STREAM SUBDIVISIONS

MAPS.BNS - MEAN AREAL PRECIPITATION AREAS

MAJOR.BNS - MAJOR STREAMS \> 200 SQUARE MILES

URBAN.BNS - URBAN AREAS

DIRECT ACCESS READ:

READ(1,REC=IREC)RADIAL

WHERE,

ARRAY RADIAL (200) INTEGER\*2

RADIAL(200) HOLDS DATA FOR AN SINGLE 1-DEGREE RADAR RADIAL.

THE ODD NUMBER ENTRIES IN THE ARRAY ARE RADAR RANGE IN

KILOMETERS, WHILE THE EVEN NUMBER ENTRIES ARE THE NUMBER OF

THE STREAM, M.A.P AREA OR URBAN AREA. UNUSED ENTRIES AT THE

END OF THE ARRAY ARE FILLED WITH -1.

**B.10.2 OPERATIONAL FILE NAMES:**

SAME FILENAMES AS THE DATA ENTRY FILENAMES, BUT WITH A

THREE LETTER EXTENSION OF \*.AMB

FOR EXAMPLE: PRIMARY STREAMS = PRIMARY.AMB

DIRECT ACCESS READ:

READ(1,REC=IREC)IDATA

ARRAY IDATA(512) INTEGER\*2

RADIAL DATA FROM THE \"DATA ENTRY FILE\" IS PACKED INTO THE

IDATA(512) ARRAY USING THE FOLLOWING FORMAT.

-1 jjj rrr bbb rrr bbb \... rrr bbb -1 jjj \.... -2 -2

THE -1 IS AN INDICATOR THAT THE NEXT NUMBER IS A RADAR

AZIMUTH (jjj) FROM 0 TO 359 DEGREES.

rrr = RADAR RANGE IN KILOMETERS (CENTER OF BIN)

IF rrr = 10, THE CENTER OF THE BIN IS AT 10.5 km FROM

THE RADAR. VALUES OF rrr MUST INCREASE ALONG A RADIAL.

bbb = STREAM NUMBER, M.A.P. NUMBER, OR URBAN AREA NUMBER.

THE NUMBER USED FOR THE STREAM, M.A.P. OR URBAN AREA

MUST BE A VALID VALUE STORED IN THE AMBER DATABASE.

-2 -2 = AN INDICATOR FOR THE END OF THE FILE.

FOR THE 21 DEGREE RADAR AZIMUTH PASSING THROUGH STREAM 1200

FOR 1km TO 22km AND STREAM 1375 FROM 23km TO 44km ENDING THIS

RADIAL, THE DATA STRING WOULD APPEAR AS:

-1 21 1 1200 23 1375 45 0 -1 22 START OF THE 22 DEGREE RADIAL)

**B.10.3 ASCII FILENAMES**

SAME FILENAME CONVENTION AS THE \"DATA ENTRY FILENAME\",

BUT WITH A THREE LETTER EXTENSION OF \*.ASK

FORMATTED WRITE:

WRITE(1,150)JDATA

150 FORMAT(10X,8I5)

ARRAY JDATA(8) INTEGER\*2

PRINTING OF THIS FILE ALLOWS FOR MANUAL ERROR CHECKING OF

THE OPERATIONAL DATA FILE. THE FILE IS PRODUCE BY READING

THE CORRESPONDING \*.AMB FILE AND WRITING THE RESULTS TO THE

TARGET \*.ASK FILE IN ASCII FORMAT.

THE ASCII FILE CAN ALSO BE USED TO TRANSFER THE DATA BETWEEN

COMPUTER SYSTEMS WHERE A BINARY TRANSFER IS NOT POSSIBLE.

**B.11 STATES. AMB file**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**STATES.AMB RECORDS IREC = 1 - 59 RECL = 22 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

RECORD NUMBER = STATE NUMBER (1 TO 59)

DIRECT ACCESS WRITE:

WRITE(1,REC=IREC)SID,STNAME

WHERE,

SID = STATE IDENTIFICATION CHARACTER\*2

STNAME = STATE NAME CHARACTER\*20

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**STATES.AMB RECORD IREC = 60 RECL = 22 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

RECORD NUMBER IREC = 60

DIRECT ACCESS WRITE:

WRITE(1,REC=IREC)CCC,AMBDATA

WHERE,

CCC = THREE LETTER ID OF THE NWSFO CHARACTER\*3

ARRAY AMBDATA(9) INTEGER\*2

AMBDATA(1) = NUMBER OF COUNTIES

AMBDATA(2) = NUMBER OF RIVER GAGE SITES

AMBDATA(3) = HIGHEST NUMBERED PRIMARY STREAM

AMBDATA(4) = HIGHEST NUMBERED STREAM SUBDIVISION

AMBDATA(5) = NUMBER OF 7.5 MINUTE QUADRANGLES

AMBDATA(6) = NUMBER OF OBSERVING SITES

AMBDATA(7) = HIGHEST NUMBERED MEAN AREAL PRECIPITATION AREA

AMBDATA(8) = HIGHEST NUMBERED MAJOR STREAM

AMBDATA(9) = HIGHEST NUMBERED URBAN AREA

VALID NUMBERS FOR EACH CATEGORY ARE:

COUNTIES: 1 - 32767

RIVER GAGE SITES: 1 - 32767

PRIMARY STREAMS: 1000 - 3999

STREAM SUBDIVISIONS: 5000 - 9999

TOPOGRAPHIC QUADRANGLES: 1 - 32767

OBSERVING SITES: 1 - 32767

MEAN AREAL PRECIPITATION AREAS 100 - 499

MAJOR STREAMS \> 200 SQ MILES: 500 - 999

URBAN AREAS: 4000 - 4999

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**STATES.AMB RECORD IREC = 61 RECL = 22 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

RECORD NUMBER IREC = 61

DIRECT ACCESS WRITE:

WRITE(1,REC=IREC)WSR88D

WHERE,

ARRAY WSR88D(7) INTEGER\*2

WSR88D(1) = WSR88D LATITUDE (degrees)

WSR88D(2) = WSR88D LATITUDE (minutes)

WSR88D(3) = WSR88D LATITUDE (seconds)

WSR88D(4) = WSR88D LONGITUDE (degrees)

WSR88D(5) = WSR88D LONGITUDE (minutes)

WSR88D(6) = WSR88D LONGITUDE (seconds)

WSR88D(7) = RADAR HEIGHT ABOVE MEAN SEA LEVEL (feet)

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**STATES.AMB RECORDS IREC = 62 - 73 RECL = 22 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

RECORD NUMBER = CANADIAN PROVINCE NUMBER (62 TO 73)

DIRECT ACCESS WRITE:

WRITE(1,REC=IREC)SID,STNAME

WHERE,

SID = PROVINCE IDENTIFICATION CHARACTER\*2

STNAME = CANADIAN PROVINCE NAME CHARACTER\*20

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**STATES.AMB RECORDS IREC = 74 - 79 RECL = 22 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

RECORD NUMBER = MEXICAN STATES NUMBER (74 TO 79)

DIRECT ACCESS WRITE:

WRITE(1,REC=IREC)SID,STNAME

WHERE,

SID = STATE IDENTIFICATION CHARACTER\*2

STNAME = MEXICAN STATE NAME CHARACTER\*20

**B.12 TOPO.AMB FILE**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**TOPO.AMB FILE RECL = 120 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

DIRECT ACCESS WRITE:

WRITE(1,REC=1)MINLAT,MAXLAT,MINLON,MAXLON,IMAP

WHERE,

MINLAT = MINIMUM LATITUDE IN THE DATABASE REAL\*4

MAXLAT = MAXIMUM LATITUDE IN THE DATABASE REAL\*4

MINLON = MINIMUM LONGITUDE IN THE DATABASE REAL\*4

MAXLON = MAXIMUM LONGITUDE IN THE DATABASE REAL\*4

IMAP = TOTAL NUMBER OF MAPS IN THE DATABASE I\*4

DIRECT ACCESS WRITE:

WRITE(1,REC=IREC)MLAT,MLON,MNUMBER,MAMBER

WHERE,

MLAT(10) LATITUDE OF SW CORNER OF 10 MAPS REAL\*4

MLON(10) LONGITUDE OF SW CORNER OF 10 MAPS REAL\*4

MNUMBER(10) REFERENCE GRID NUMBER OF 10 MAPS INTEGER\*2

MAMBER(10) AMBER RECORD NUMBER OF 10 MAPS INTEGER\*2

GRID REFERENCE NUMBER 1 IS ASSIGNED TO THE MAP WITH THE MOST NORTHERN
LATITUDE AND MOST WESTERLY LONGITUDE IN THE DATABASE.

THE REMAINING REFERENCE GRID NUMBER ARE CREATED BY INCREMENTING THE GRID
NUMBER BY ONE FOR EACH 7.5 MINUTES IN THE EASTERLY DIRECTION. WHEN THE
LOWEST LONGITUDE IN THE DATABASE IS REACHED, THE PROGRAM DECREASES THE
LATITUDE BY 7.5 MINUTES, MOVES BACK TO THE MOST WESTERLY MAP IN THAT ROW
AND CONTINUES NUMBERING ALONG THE ROW OF TOPOGRAPHIC MAPS. THIS
PROCEDURE CONTINUES UNTIL THE MAXIMUM LATITUDE AND MINIMUM LONGITUDE OF
THE DATABASE IS REACHED.

**B.13 COUNTIES.xx FILES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**COUNTIES.xx FILES; where xx = STATE ID RECL = 44 BYTES**

**+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

DIRECT ACCESS READ:

READ(1,REC=1)CNUMBER

WHERE,

CNUMBER = NUMBER OF COUNTIES IN THE STATE INTEGER\*2

DIRECT ACCESS READ:

READ(1,REC=IREC)CNAME,CFIPS,CWARN,ZONE

WHERE,

CNAME = NAME OF COUNTY CHARACTER\*20

CFIPS = COUNTY FIPS CODE CHARACTER\*6

CWARN(2) = WARNING AND BACKUP WARNING OFFICE CHARACTER\*3

ZONE(2) = ZONE FIPS CODE CHARACTER\*6

NOTE: If county has more than two zone fips codes use the first and last
zone codes.

IREC = RECORD NUMBER, COUNTY REFERENCE NUMBER IN THE AMBER

COUNTY DATABASE FILE = IREC - 1

**B.14 THE PRIMARY STREAM ABR DATABASE**

**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**Pyymmdd.AMB; yymmdd = the year, month and day of the month. RECL=4000
bytes.**

**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

Record number 1 contains the arrays:

TSTART(400) INTEGER\*2 (start time of the rainfall duration in seconds
since midnight)

TEND (400) INTEGER\*2 (end time of the rainfall duration in seconds
since midnight)

TSTATUS(400) INTEGER\*2 (physical record number where this rainfall
duration is stored)

The first TSTATUS array position, TSTATUS(1) stores the physical record
number of the last volume scan stored in the database. The first TSTART
array position, TSTART(1) holds the WSR-88D Julian date of the ABR data
stored in this file. The first TEND array position is not used.

The table below shows the contents of the first ten slots of the
TSTATUS, TSTART, and TEND arrays for the 15^th^ of March, 1997 at the
Pittsburgh NWSFO.

ARRAY Slot = 1 2 3 4 5 6 7 8 9 10

STATUS = 10 2 3 4 5 6 7 8 9 10

START = 9936 -2 348 700 1052 1404 1756 2107 2458 2809

END = 0 348 700 1052 1404 1756 2107 2458 2809 3162

GMT time (-2 =2359) 0005 0011 0017 0023 0029 0035 0040 0046 0052

Table 3. Contents of the TSTATUS, TSTART AND TEND arrays for the first 9
volume scans of the new Julian day starting at 0000 GMT on March 15,
1997.

A negative start time (-2) is the number of seconds prior to midnight
(86,400 seconds in 24 hours) that the rainfall duration began. All Start
and end times are in seconds since midnight. The actual GMT time for the
END seconds after midnight are shown in the bottom row. The MSDOS
program "HOUR" will do this conversion. Notice the WSR-88D Julian day in
the first array slot of the START times (9936) is March 15^th^, 1997.
The "JD88D" MSDOS program can be used to compute the WSR-88D Julian day
for any month, day, year combination.

The rainfall in array slot 4 fell from 0011 GMT to 0017 GMT. The WSR-88D
was in VCP11, resulting in 6 minute rainfall durations for almost all
scans. .

Each radar volume scan for the GMT day will have an entry in each of
these three arrays. The first rainfall duration with an ending time in
the new GMT day will be at array position 2. Each new volume scan will
be entered in consecutive array positions. With the radar in VCP11 (a
volume scan every 5 minutes) the maximum number of volume scans in a day
will be 288. A -2 is stored in all unused STATUS array slots. A zero is
stored in all unused START and END arrays slots.

Record numbers 2 and higher hold a single array:

PDATA(2000) INTEGER\*2 (amount of ABR in thousandths of an inch.)

Array position = primary stream number - 999.

For example: If the PDATA array is written to the Primary Stream ABR
file for March 15^th^ , 1997 into physical record 4, and the PDATA(88)
position holds a value of 345. This means that primary stream number
1087, had an Average Basin Rainfall (ABR) of 0.345 inches of rainfall in
the 6 minute period from 0011 to 0017Z on March 15, 1997.

**B.15 THE SUBDIVISION ABR DATABASE**

**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**Syymmdd.AMB; yymmdd = the year, month and day of the month. RECL=4000
bytes.**

**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

Record number 1 contains the arrays:

TSTART(400) INTEGER\*2 (start time of the rainfall duration in seconds
since midnight)

TEND (400) INTEGER\*2 (end time of the rainfall duration in seconds
since midnight)

TSTATUS(400) INTEGER\*2 (physical record number where this rainfall
duration is stored)

These arrays hold the identical information as the same three arrays in
the Primary ABR file.

Record numbers 2 and higher holds a single array:

SDATA(2000) INTEGER\*2 (amount of ABR in thousandths of an inch.)

Array position = subdivision number - 4999.

**B.16 THE MAP AREA/MAJOR STREAM/URBAN AREA ABR DATABASE**

**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

**Uyymmdd.AMB; yymmdd = the year, month and day of the month. RECL=4000
bytes.**

**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**

Record number 1 contains the arrays:

TSTART(400) INTEGER\*2 (start time of the rainfall duration in seconds
since midnight)

TEND (400) INTEGER\*2 (end time of the rainfall duration in seconds
since midnight)

TSTATUS(400) INTEGER\*2 (physical record number where this rainfall
duration is stored)

These arrays hold the identical information as the same three arrays in
the Primary ABR file.

Record number 2 and higher holds a single array:

UDATA(2000) INTEGER\*2 (amount of ABR in thousandths of an inch.)

Array slot Valid stream number

MAP area array slot = MAP number - 99 1 - 400 100 - 499

Major stream array slot = Major number - 99 401 - 999 500 - 999

Urban area array slot = Urban number - 3099 901 - 1900 4000 - 4999

**B.17 THE FLASH FLOOD GUIDANCE (FFG) FILE**

The AMBER FFG is created every time the file FFG.NEW is transferred from
the MSDOS computer, where it is created from seven different AFOS flash
flood guidance produce. The FFG.NEW file is an ASCII text file with one
line of data for each county in the AMBER county database. The counties
are arranged numerically in the file by their AMBER county number. The
first two lines of the March 15, 1997 FFG.NEW file are listed below:

7.  1.1 1.4 1.7 2.2 PAZ021 ALLEGHENY 1 PAC003

0.6 1.0 1.2 1.6 2.0 PAZ022 ARMSTRONG 2 PAC005

The first five columns are the 1-hour, 3-hour, 6-hour, 12-hour and 24
hour FFG in inches. The FFG values are followed by the "zone forecast
number" for the county, the county name, the AMBER county number, and
finally the "county warning number" for each county.

When the AMBER real time software detects a FFG.NEW file (the software
checks at the start of each volume scan), it reads the FFG values and
stores them in memory, and renames the FFG.NEW file to a filename of the
form:

ffgyymmdd_hh:mm, where yy = year, mm = month, dd = day of the month,
hh:mm = the GMT time the FFG.NEW file was processed. The file is the
same exact ASCII format as the original FFG.NEW file, but this process
allows the archive of the FFG data. The FFG stored on March 1, 1997 at
1650 GMT is stored as filename: ffg970301_16:50.

**B.18 The AMBER Warning/Alert File**

This file is an ASCII text file that summarizes all AMBER alarms
produced for each radar volume scan A report is written to the file for
any watershed that reaches 60% of any FFG value of time durations of
three hours or less. This summary gives a table of rainfall
accumulations of 20,40, 60, 120 and 180 minutes of rainfall for each
alarmed watershed, plus the FFG and alert level. Yellow alert = 80% of
FFG, red alert = 100% of FFG, red! alert = 200% of FFG, and red!! alert
= 300 % FFG. This data is scrolled to the SAC terminal screen and
written to this ASCII text file. The AMBER Warning/Alert file is given
by the filename: Wyymmdd.AMB ; where yy = year, mm = month and dd = day
of month. One file is created for each GMT day.

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Basin 5490 CLARION, PA (PBZ) 07/19/96 06:00

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Duration (hr) 0.33 0.67 1.0 2.0 3.0

AMBER (in) 0.20 0.40 0.70 0.70 0.70

FFG (in) 1.10 1.10 1.10 1.50 1.90

AMBER/FFG (%) 18 36 63 46 36

Alert Category - - - - -

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Basin 5490 CLARION, PA (PBZ) 07/19/96 07:00

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Duration (hr) 0.33 0.67 1.0 2.0 3.0

AMBER (in) 0.30 0.60 0.90 1.60 1.60

FFG (in) 1.10 1.10 1.10 1.50 1.90

AMBER/FFG (%) 27 54 82 107 84

Alert Category - - yellow red yellow

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Basin 5490 CLARION, PA (PBZ) 07/19/96 08:00

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Duration (hr) 0.33 0.67 1.0 2.0 3.0

AMBER (in) 0.30 0.70 1.10 2.00 2.70

FFG (in) 1.10 1.10 1.10 1.50 1.90

AMBER/FFG (%) 27 64 100 133 142

Alert Category - - red red red

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Basin 5490 CLARION, PA (PBZ) 07/19/96 09:00

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Duration (hr) 0.33 0.67 1.0 2.0 3.0

AMBER (in) 0.60 1.30 1.90 3.00 3.90

FFG (in) 1.10 1.10 1.10 1.50 1.90

AMBER/FFG (%) 55 118 173 200 205

Alert Category - red red red! red!

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Basin 5490 CLARION, PA (PBZ) 07/19/96 10:00

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Duration (hr) 0.33 0.67 1.0 2.0 3.0

AMBER (in) 0.30 0.70 1.00 2.90 4.00

FFG (in) 1.10 1.10 1.10 1.50 1.90

AMBER/FFG (%) 27 64 91 193 211

Alert Category - - - red red!

A devastating flash flood struck western Pennsylvania on July 19, 1996.
Ten counties in western Pennsylvania were declared disaster areas:
Armstrong, Blair, Cambria, Clarion, Clearfield, Crawford, Greene,
Indiana, Jefferson and Venango. The time series of AMBER alert/warning
printouts above is for the headwaters of Deer Creek in Clarion county
during this flood event. A trailer court in the headwaters of Deer Creek
near Shippenville, PA was destroyed during the flood, resulting in the
only fatality in Pennsylvania for this destructive flash flood. The
trailer court was destroyed around 930 GMT.

AMBER first alerted the forecaster at 0600 GMT when the 1-hour ABR
exceeded 60% of flash flood guidance. The headwaters of Deer Creek would
initially come out of it's banks when the ABR reach 100% of the 2-hour
FFG at about 0700 GMT. With the stream already flooding and the ground
completely saturated, all the additional rainfall that fell from 0700 to
1000 GMT went almost exclusively into runoff. Keep in mind that the FFG
values are not modified by AMBER, and that they remain constant until
updated by the RFC. The forecaster must keep this fact in mind, as the
severity of the flooding event is being determined. Even with the FFG
held constant, the ABR reached 200 percent of FFG at 09z indicating
significant flash flooding in progress.

Keep in mind that the forecaster receives an AMBER update every volume
scan of the radar, (every 5-6 minutes) not at one hour intervals. One
hour intervals are shown for this event due to the modest flash flood
rainfall rates of about 1 in/hr for 4 of the 5 hours of this event. The
rainfall rate for the maximum hour 0800 to 0900 GMT was 1.90 inches. In
the Little Pine Creek Flood of 1986 in Etna, PA, the rainfall rate was
4.5 in/hr for a 1.5 hour period. In these high intensity rainfall
events, the 20 minute and 40 minute time periods displayed by AMBER
become much more important. Notice for the Deer Creek event, the 20
minute duration never reach 1-hour FFG and the 40 minute time duration
exceeded the 1-hour FFG only during the 0800 to 0900z time period.

**Appendix C. Transfer of the AMBER Database from a DOS to an UNIX
Platform.**

**C.1 Create ASCII files of all AMBER databases on the DOS platform.**

**C.1.1 ASKII** - this program will create an ASCII version of twelve
AMBER data files:

The nine files created and maintained by the program AMBERFIX:

xxx1.ASK

xxx2.ASK

xxx3.ASK

xxx4.ASK

xxx5.ASK

xxx6.ASK

xxx7.ASK

xxx8.ASK

xxx9.ASK

STATES.ASK

TOPO.ASK

xxxQUAD.ASK Where xxx = the three letter identifier of the forecast
office.

**C.1.2 BINFIX** - this program will create An ASCII version of the
seven radar bin designation files:

PRIMARY.ASK

SUBS1.ASK

SUBS2.ASK

SUBS3.ASK

MAJOR.ASK

MAPS.ASK

URBAN.ASK

**C.1.3 MAKEBINS** -this program will create an ASCII version of the
files containing a count of the number of radar bins in each watershed
database:

PRIBINS.ASK

SUBBINS.ASK

URBBINS.ASK

**C.2 Use File Transfer Protocol (FTP) software to transfer the 22 ASCII
files created above and the amber_rc.input (C.4) and amber_adapt.input
(C.5) to the UNIX platform.**

**C.3 On the UNIX platform, convert the ASCII files to direct access
files using the following programs:**

**C.3.1 AMB** - this program converts the STATES.ASK file to STATES.AMB.

**C.3.2 DIRECT**- this program converts the other eleven files created
by the ASKII program to direct access files on the UNIX platform. This
program also converts the ASKII files created by the MAKEBINS program
into direct access files.

**C.3.3 DIRBIN** - this program converts the ASCII radar bin assignment
files (7 files) to direct access radar bin assignments with the file
extension BNS.

**C.3.4 BINS** - this program converts the seven direct access radar bin
assignment data files with the extension BNS, to operational AMBER radar
bin assignment data files with the extension AMB.

**C.4 The amber_rc.input file.**

The operational AMBER software on the UNIX platform uses the
amber_rc.input file to determine where all AMBER data files may be
found. All files created in step C3 with the extension of AMB, must be
copied to the subdirectory listed for each data file in the
amber_rc.input file. The amber_rc.input file is an ASCII text file with
the following format

for the Pittsburgh NWSFO AMBER database:

/usr1/rt_amber ; the location of the hybrid scan data files.

/usr1/amber/dbase/amber_adapt.input ; the location of AMBER adaptation
data file.

**/usr1/amber/dbase/primary.amb ; these lines in bold show the location
of the AMBER**

**/usr1/amber/dbase/subs1.amb ; stream basin database files used by the
AMBER.**

**/usr1/amber/dbase/subs2.amb ; operational software.**

**/usr1/amber/dbase/urban.amb**

**/usr1/amber/dbase/major.amb**

**/usr1/amber/dbase/maps.amb**

**/usr1/amber/dbase/pit1.amb**

**/usr1/amber/dbase/pit3.amb**

**/usr1/amber/dbase/pit4.amb**

**/usr1/amber/dbase/pit7.amb**

**/usr1/amber/dbase/pit8.amb**

**/usr1/amber/dbase/pit9.amb**

**/usr1/amber/dbase/states.amb**

/usr1/amber/THRLYACUM.DB ; these last four lines show the location of
the AMBER

/usr1/amber/PHRLYACUM.DB ; ABR database output files.

/usr1/amber/SHRLYACUM.DB

/usr1/amber/UHRLYACUM.DB

**C.5 The amber_adapt.input file.**

The AMBER adaptation data file is used to set various parameters used by
the AMBER operational software. The contents of the Pittsburgh NWSFO
AMBER adaptation data file is shown below:

300.0 CZM /300.0/ Z-R Multiplicative Coefficient

1.4 CZP /1.4/ Z-R Power Coefficient

25 MAXSPDSTM /25/ Maximum Storm Speed (m/s)

150.0 THRMXTDIF /15.0/ Threshold Time Difference (min)

200 MINARTIMC /200/ Minimum Area Time Continuity (km\*\*2)

24.0 PRMTIMC1 /24.0/ Time Continuity Parameter #1 (/hr)

13.2 PRMTIMC2 /13.2/ Time Continuity Parameter #2 (/hr)

200 MAXRATCHG /200/ Maximum Rate Echo Area Change (km\*\*2/hr)

127.0 MAXPRATE /127.0/ Maximum Precipitation Rate (mm/hr)

60 TIMRESTRT /60/ Restart Time (min)

30 MAXTIMINT /30/ Maximum Time Interpolation (min)

20 40 60 120 180 (5I4) AMBER Hourly Accumulation Times (min)

1.0 1.0 1.0 0.5 1.0 (5f4) Hourly FFG adjustment factors (none)

80 Yellow FFG threshold (% of FFG)

100 Red FFG threshold (% of FFG)

PBZ WFO ID for County Warning Area (all capitals!)

CLE ID for WFO Actively Being backed up (all capitals!)

The AMBER accumulations times set the five time durations of ABR that
will be compared to FFG. The Hourly FFG adjustment factors determine how
the FFG is calculated from the RFC FFG. The RFC FFG is available in
1-hour, 3-hour, 6-hour, 12-hour and 24-hour time durations. If the AMBER
time duration matches any of the FFG durations exactly, enter a 1.0 into
the hourly FFG adjustment factor for that time period. One hour FFG
should be used for all time durations of an hour or less. Notice the 120
minute AMBER time duration has a 0.5 FFG adjustment. Since the 2 hour
time duration is between the 1-hour and 3-hour FFG time, the value for
the 120 minute time duration will be set by

2 hour ffg = 1-hour ffg + (ffg adjustment) \* (3-hour ffg - 1hour ffg)

If the ffg adjustment is set to 0.5, the 2-hour guidance will equal the
1-hour FFG plus one half of the difference of the 3-hour and 1-hour FFG.
This allows the uses to set the 2-hour FFG to any value between the
3-hour and the 1-hour FFG. If a ffg adjustment of 0.5 is selected, a
linear extrapolation is performed.

The yellow and red percentage of FFG alert levels are set at 80 % and
100%, but may be set to any desired percentage of FFG.