INTRODUCTION

This study compares NEXRAD-estimated storm-total precipitation with

rain-gauge measured total precipitation for five events:

a. Missouri-Kansas in April 1994, Kansas City NEXRAD site.

b. Southeast Texas in October 1994, Houston NEXRAD site.

c. Florida in November 1994 (Hurricane Gordon), Melbourne NEXRAD

site.

d. Louisiana-Mississippi-Alabama in May 1995, Mobile and Slidell

NEXRAD sites.

e. South Carolina-North Carolina-Georgia in August 1995 (Tropical

Storm Jerry), Columbia NEXRAD site.

DATA

The hourly and daily precipitation data from the National Climatic Data

Center (NCDC) were used to determine actual precipitation (ground truth)

during the period in which the storm total precipitation estimates were

determined by the NEXRAD level III data. These hourly and daily

precipitation amounts are taken from the National Weather Service and

cooperative network of weather stations. Across the country, over 8000 of

these cooperative stations generally record daily precipitation and

maximum/minimum temperature data, with approximately 2500 sites reporting

hourly precipitation amounts.

The total amount of NEXRAD-estimated rainfall was determined by magnifying

the original NEXRAD images and locating the latitude and longitude of the

reporting stations. The computer system used to perform these estimates

located the positions in degrees, minutes, and seconds. Since the rainfall

estimates were obtained visually from the image, a range and midpoint are

shown in this report. The range represents the boundaries of uncertainty

in applying a color-coded map to one location. To some extent, this also

represents the range of uncertainty a forecaster or hydrologist might

encounter.

In addition to the estimated storm total precipitation, the distance from

the radar sites to each station was approximated. Using these distances,

it was then possible to determine how the actual observed rainfall on the

surface compared to that estimated by the NEXRAD system as the distance

from the radar site to the observing site increased. Note that the outer

limit of NEXRAD for estimating precipitation is 124 nautical miles, while

the distance from radar site to each station is shown in Tables 1-6 in

statute miles. This accounts for some stations being over 124 (statute)

miles in distance.
DISCUSSION

The five events were chosen due to their extensive and damaging nature, and

due to the availability of one or more NEXRAD sites with good areal

coverage. All five events were at least somewhat convective in nature, so

this study is more reflective of radar performance in convective

situations. However, since most damaging flood events tend to be at least

partly convective, we felt it appropriate to focus on the five included in

this report.

The tables and figures show the estimated difference between actual

(rain-gauge measured) rainfall and NEXRAD-estimated rainfall. In 80% of

the 220 stations checked, the NEXRAD estimates were too low, sometimes by a

factor of 2 to 3. The best performances overall appear in the May 95 event

with the Mobile NEXRAD site along with the Apr 94 event with the Kansas

City site, while the worst overall was the Oct 94 event with the Houston

NEXRAD site. This report will not attempt to delve into explanations of

this performance, as the National Severe Storms Laboratory and others are

already conducting such studies. We can report that some sites have

changed their precipitation processing parameters (adaptable parameters) to

attempt to improve the rainfall estimates.

Additional findings include:

a. Concentric circles on some storm-total displays (especially

Houston), possibly due to the algorithms used to adjust for distance

from the radar site.

b. No significant correlation between distance of station (rain gauge)

from radar site vs. departure of radar-estimated rainfall from the actual

(rain gauge) amount. In other words, as distance from the site increases,

we generally did not find a deterioration in NEXRAD performance (rainfall

estimates) for these five events.

c. The NEXRAD-estimated rainfall (for the six sites) fell an average of

2.9 inches below the actual amounts recorded by the rain gauges. The best

(closest) were the Kansas City site with an average of near 0.0 (some below

and some above zero) and Mobile with a -.2 inch average, while the greatest

departure was Houston with an average of -8.2 inches. Stated as a

percentage, the NEXRAD-estimated rainfall averaged 69% of the actual

measured amounts. The best (closest) were the Kansas City and Mobile sites

with 102% and 98%, respectively. The lowest were Columbia and Houston with

43% and 46%, respectively.

d. The percent of stations overall whose measured amounts fell within the

NEXRAD-estimated range (>range of estimates= on tables) was 27%. Again, the

two >best= sites were Kansas City and Mobile with 60% and 46%, respectively.

 The lowest were Columbia and Houston with 2% and 0%, respectively.
TABLES AND FIGURES

The five heavy rain events and their associated tables and figures are

listed below. The figures showing the total measured precipitation have

the NEXRAD radar site location plotted on the map for reference. We were

careful to ensure that the times for NEXRAD-estimated storm total

precipitation coincided with the times for the rainfall from the

cooperative stations. Additional NEXRAD images (such as hourly rainfall)

were also studied during this process.

a. Missouri-Kansas on April 10-11, 1994 (Kansas City NEXRAD site)--

Table 1, Figures 1-3. Heaviest measured rainfall--8.60 inches.

Rainfall associated with quasi-stationary front.

b. Southeast Texas on October 15-20, 1994 (Houston NEXRAD site)--

Table 2, Figures 4-6. Heaviest measured rainfall--26.37 inches.

Rainfall associated with quasi-stationary front and 'training'

thunderstorms.

c. Florida on November 14-18, 1994 (Melbourne NEXRAD site)--Table 3,

Figures 7-9. Heaviest measured rainfall--10.93 inches. Rainfall

associated with Hurricane Gordon, with most rain falling in 2-day

period.

d. Louisiana-Mississippi-Alabama on May 8-13, 1995 (Mobile and Slidell

NEXRAD sites)--Tables 4-5, Figures 10-13. Heaviest measured

rainfall--24.99 inches. Rainfall associated with slow-moving cold front

and tropical moisture.

e. South Carolina-North Carolina-Georgia on August 23-29, 1995

(Columbia NEXRAD site)--Table 6, Figures 14-16. Heaviest measured

rainfall--15.13 inches. Rainfall associated with Tropical Storm Jerry,

with most rain falling in 2-day period.
SUMMARY

This report should provide researchers with additional data and information

in studies of NEXRAD performance and algorithm-enhancement. The Mobile site

performance was encouraging in light of the extensive and prolonged nature

of that event. Of course, some of the other events showed that further

work and improvements are needed. 

The recently issued National Disaster Survey Report on Tropical Storm

Alberto (National Weather Service, December 1995) touched on the

underestimation problem and the need to incorporate automated rain

gauge data into NEXRAD estimates. This report echoes that finding. Of

course, we expect that adjustments in adaptable parameters as mentioned

earlier will also improve the estimates.

For additional meteorological data, NEXRAD data/images, or other

information, please contact NCDC: phone 704-271-4800, fax 704-271-4876,

email 'orders@ncdc.noaa.gov'. Also, this report and a great deal of other

information and data can be found on our WWW homepage --

http://www.ncdc.noaa.gov.

Finally, many thanks to NCDC=s John Kobar and Bob Boreman for their expert

assistance in selection and use of the NEXRAD level III data.
Guide to NEXRAD Tables:

The following statistics are shown for individual stations in each case:

station: location of precipitation (rain gauge) report.

lat. de/mi: latitude of the station, in degrees and minutes (North).

long. de/mi: longitude of the station, in degrees and minutes (West).

(mi.) dist: distance, in statute miles, from the station to the radar 

 site.

prec. tot.: total precipitation, in inches, received at the station.

range of

estimates: the range (lowest and highest) of storm total precipitation

 as estimated from the storm total precipitation plots 

 (NEXRAD).

avg. est.: the average of the lowest and highest estimates of total

 precipitation (NEXRAD)--i.e., the midpoint of (range of

estimates) rounded to tenths.

 

avg. - obs.: the average estimate (NEXRAD) of total precipitation

 minus the total precipitation actually received at the 

 station--calculated by subtracting (prec. tot.) from the

 arithmetic midpoint of (range of estimates).

ir (in range): if the precipitation total is within the NEXRAD-estimated

 bounds, a 'Y' for yes is shown, otherwise an 'N' for no is 

 shown.

The following summary statistics are shown for each NEXRAD site:

averages: arithmetic average values are listed for the total precipitation

received, average estimate (NEXRAD), and the station-by-station difference

between the two values (avg. - obs.).

NEXRAD est. as % of measured: average NEXRAD estimate divided by the

average precipitation total at all stations, expressed as a percentage.

distance/difference correlation: the correlation of the differences

between average estimate and total precipitation received, and the

distance from each station to the radar site--i.e., an expression of the tendency

for radar performance to decrease with increasing distance from the radar--

indicated by a positive correlation.

% of stns. with prec. in est. range: percent of stations with total

precipitation between the lowest and highest NEXRAD-estimated values.
TABLE 1 KANSAS CITY, MO (KEAX) April 10-11, 1994

 lat. long (mi.) prec range of avg. avg.-

station de mi de mi dist tot. estimates est. obs. ir

UNITY VILLAGE, MO 38 57 94 24 12 0.90 0.1 2.0 1.1 0.2 Y

ELM, MO 38 52 94 02 13 1.40 1.0 2.0 1.5 0.1 Y

STANLEY, KS 38 49 94 40 21 0.90 0.1 1.0 0.6 -0.4 Y

SHAWNEE 2S, KS 38 59 94 43 27 0.70 0.1 1.0 0.6 -0.2 Y

DREXEL, MO 38 29 94 36 28 1.50 1.0 2.0 1.5 0.0 Y

HILLSDALE LAKE, KS 38 40 94 54 35 0.80 1.0 2.0 1.5 0.7 N

CLINTON, MO 38 24 93 46 38 3.50 4.0 6.0 5.0 1.5 N

KEARNEY 2E, MO 39 22 94 20 38 0.70 1.0 2.0 1.5 0.8 N

KANSAS CITY WSMO AP, MO 39 19 94 43 42 0.46 0.1 1.0 0.6 0.1 Y

SMITHVILLE LAKE, MO 39 23 94 33 42 0.70 0.1 1.0 0.6 -0.2 Y

APPLETON CITY, MO 38 12 94 02 43 2.80 4.0 6.0 5.0 2.2 N

OTTAWA, KS 38 37 95 17 56 1.00 1.0 2.0 1.5 0.5 Y

MARSHALL, MO 39 07 93 13 60 1.70 3.0 6.0 4.5 2.8 N

BLUE MOUND, KS 38 06 95 01 63 2.00 2.0 3.0 2.5 0.5 Y

PERRY LAKE, KS 39 07 95 25 65 0.20 0.0 0.1 0.1 -0.2 N

NEVADA SEWAGE PLANT, MO 37 51 94 24 66 8.60 7.0 13.0 10.0 1.4 Y

POMONA LAKE, KS 38 39 95 34 71 0.60 0.1 1.0 0.6 0.0 Y

TOPEKA WSO AIRPORT, KS 39 04 95 38 75 0.16 0.0 1.0 0.5 0.3 Y

UNIONTOWN, KS 37 51 94 58 76 2.10 2.0 3.0 2.5 0.4 Y

POMME DE TERRE DAM, MO 37 55 93 19 80 3.60 3.0 5.0 4.0 0.4 Y

STOCKTON DAM, MO 37 42 93 47 80 3.70 3.0 4.0 3.5 -0.2 Y

MELVERN LAKE, KS 38 30 95 42 80 0.80 0.1 2.0 1.1 0.3 Y

NEW FRANKLIN 1W, MO 39 01 92 46 81 3.00 7.0 8.0 7.5 4.5 N

PATTONSBURG 2S, MO 40 02 94 08 84 0.60 0.1 1.0 0.6 0.0 Y

IOLA 1W, KS 37 55 95 26 88 1.50 2.0 4.0 3.0 1.5 N

HORTON, KS 39 40 95 31 89 0.30 0.0 0.1 0.1 -0.3 N

JOHN REDMOND LAKE, KS 38 15 95 45 89 1.30 1.0 3.0 2.0 0.7 Y

BOLIVAR 1NE, MO 37 36 93 25 95 3.80 2.0 4.0 3.0 -0.8 Y

LOCKWOOD, MO 37 23 93 57 99 2.70 2.0 3.0 2.5 -0.2 Y

MOBERLY, MO 39 24 92 26 106 2.00 2.0 4.0 3.0 1.0 Y

COLUMBIA WSO AP, MO 38 49 92 13 110 3.24 2.0 3.0 2.5 -0.7 N

MILLER 1E, MO 37 13 93 49 112 2.70 0.1 2.0 1.1 -1.7 N

JEFFERSON CITY WATER PLANT, MO 38 35 92 11 113 3.70 3.0 5.0 4.0 0.3 Y

LONG BRANCH RESERVOIR, MO 39 44 92 29 114 0.90 0.1 1.0 0.6 -0.4 Y

TORONTO LAKE, KS 37 45 95 56 116 1.30 1.0 2.0 1.5 0.2 Y

SPRINGFIELD WSO AP, MO 37 14 93 23 118 1.81 0.1 1.0 0.6 -1.3 N

FULTON, MO 38 51 91 57 124 3.10 0.1 2.0 1.1 -2.1 N

SPRING CITY, MO 36 59 94 32 126 3.80 0.1 2.0 1.1 -2.8 N

MCCREDIE EXPERIMENT STN, MO 38 57 91 54 127 2.72 0.1 1.0 0.6 -2.2 N

MOUND VALLEY 3WSW, KS 37 11 95 27 129 3.50 2.0 4.0 3.0 -0.5 Y

VIENNA 2WNW, MO 38 12 91 59 130 3.00 0.1 1.0 0.6 -2.5 N

SENECA, MO 36 51 94 37 136 2.70 0.1 1.0 0.6 -2.2 N

 

 averages: 2.06 2.1 0.0

 NEXRAD est. as % of measured: 102%

 distance/difference correlation: 0.34

 % of stns. with prec. in est. range: 60%
TABLE 2 HOUSTON WSO, TX (KHGX) October 15-20, 1994

 lat. long (mi.) prec range of avg. avg.-

station de mi de mi dist tot. estimates est. obs. ir

HOUSTON WSO, TX 29 28 95 05 0 4.34 0.1 1.0 0.6 -3.8 N

HOUSTON DEER PARK, TX 29 43 95 08 17 18.98 7.0 9.0 8.0 -11.0 N

HOUSTON PORT, TX 29 45 95 17 22 21.23 7.0 9.0 8.0 -13.2 N

BAYTOWN LAB, TX 29 50 95 00 25 25.66 10.0 11.0 10.5 -15.2 N

HOUSTON WESTBURY, TX 29 40 95 28 26 15.54 6.0 7.0 6.5 -9.0 N

HOUSTON HEIGHTS, TX 29 47 95 26 30 10.33 3.0 5.0 4.0 -6.3 N

HOUSTON SAN JACINTO DAM, TX 29 55 95 09 31 21.73 7.0 8.0 7.5 -14.2 N

HOUSTON INDEP HEIGHT, TX 29 52 95 25 33 8.18 3.0 4.0 3.5 -4.7 N

HOUSTON SPRING BRANCH, TX 29 48 95 30 33 9.39 3.0 5.0 4.0 -5.4 N

HOUSTON NORTH HOUSTON, TX 29 53 95 32 39 12.28 4.0 5.0 4.5 -7.8 N

LIBERTY, TX 30 03 94 48 43 26.37 10.0 11.0 10.5 -15.9 N

HOUSTON BARKER, TX 29 49 95 44 45 8.23 3.0 4.0 3.5 -4.7 N

NEW CANEY 2E, TX 30 08 95 11 46 18.24 6.0 7.0 6.5 -11.7 N

CYPRESS, TX 29 58 95 42 50 8.30 3.0 5.0 4.0 -4.3 N

NEW GULF, TX 29 16 95 54 51 13.30 3.0 4.0 3.5 -9.8 N

ANAHUAC, TX 29 47 94 17 52 10.31 5.0 7.0 6.0 -4.3 N

TOMBALL, TX 30 06 95 37 54 14.82 5.0 8.0 6.5 -8.3 N

CLEVELAND, TX 30 22 95 05 61 23.40 11.0 13.0 12.0 -11.4 N

BEAUMONT RESEARCH CTR, TX 30 04 94 17 62 19.20 10.0 13.0 11.5 -7.7 N

WHARTON, TX 29 19 96 06 62 13.05 8.0 9.0 8.5 -4.6 N

CONROE, TX 30 20 95 29 64 23.42 13.0 15.0 14.0 -9.4 N

SEALY, TX 29 47 96 08 66 11.12 6.0 8.0 7.0 -4.1 N

PIERCE 1E, TX 29 14 96 11 68 14.73 8.0 10.0 9.0 -5.7 N

COLDSPRING 5SSW, TX 30 32 95 09 73 13.96 9.0 11.0 10.0 -4.0 N

MONTGOMERY, TX 30 23 95 42 73 20.71 11.0 15.0 13.0 -7.7 N

DANEVANG 1W, TX 29 03 96 14 75 10.17 3.0 5.0 4.0 -6.2 N

DACUS, TX 30 26 95 47 78 18.18 9.0 11.0 10.0 -8.2 N

KOUNTZE, TX 30 23 94 18 78 19.69 8.0 10.0 9.0 -10.7 N

WILDWOOD, TX 30 33 94 27 83 14.71 7.0 9.0 8.0 -6.7 N

LIVINGSTON, TX 30 44 94 56 87 14.98 6.0 8.0 7.0 -8.0 N

RICHARDS, TX 30 33 95 51 87 16.68 8.0 9.0 8.5 -8.2 N

COLUMBUS, TX 29 43 96 32 88 6.30 2.0 3.0 2.5 -3.8 N

HUNTSVILLE, TX 30 43 95 33 90 13.52 6.0 7.0 6.5 -7.0 N

BRENHAM, TX 30 10 96 24 92 15.19 5.0 7.0 6.0 -9.2 N

SPEAKS 2S, TX 29 17 96 42 98 13.53 6.0 7.0 6.5 -7.0 N

EDNA HIWAY 59 BRIDGE, TX 28 58 96 41 102 18.28 5.0 7.0 6.0 -12.3 N

KIRBYVILLE, TX 30 37 93 55 105 12.00 5.0 6.0 5.5 -6.5 N

SOMERVILLE DAM, TX 30 20 96 32 105 16.99 6.0 8.0 7.0 -10.0 N

CORRIGAN, TX 31 00 94 47 106 25.98 5.0 7.0 6.0 -20.0 N

TOWN BLUFF, TX 30 48 94 11 106 8.80 4.0 6.0 5.0 -3.8 N

COLLEGE STATION FAA AP, TX 30 35 96 22 108 16.91 5.0 6.0 5.5 -11.4 N

GROVETON, TX 31 04 95 08 110 16.83 7.0 8.0 7.5 -9.3 N

CROCKETT, TX 31 18 95 27 128 5.86 2.0 5.0 3.5 -2.4 N

LUFKIN 2, TX 31 23 94 43 133 10.66 4.0 6.0 5.0 -5.7 N

 

 averages: 15.05 6.9 -8.2

 NEXRAD est. as % of measured: 46%

 distance/difference correlation: -0.09

% of stns. with prec. in est. range: 0%
TABLE 3 MELBOURNE WSO, FL (KMLB) November 14-18, 1994

 lat. long (mi.) prec range of avg. avg.-

station de mi de mi dist tot. estimates est. obs. ir

MELBOURNE WSO, FL 28 07 80 39 0 7.80 3.0 6.0 4.5 -3.3 N

VERO BEACH 4W, FL 27 39 80 25 35 8.33 5.0 7.0 6.0 -2.3 N

TITUSVILLE, FL 28 37 80 49 36 8.70 6.0 8.0 7.0 -1.7 N

FORT DRUM 5NW, FL 27 35 80 50 38 6.43 2.0 4.0 3.0 -3.4 N

ORLANDO WSO MCCOY, FL 28 27 81 19 46 5.85 3.0 5.0 4.0 -1.9 N

FORT PIERCE, FL 27 28 80 21 48 4.71 3.0 4.0 3.5 -1.2 N

SANFORD EXPERIMENT STN, FL 28 48 81 14 59 8.15 5.0 7.0 6.0 -2.2 N

STUART 1N, FL 27 13 80 15 66 6.50 4.0 5.0 4.5 -2.0 N

WINTER HAVEN, FL 28 01 81 44 66 4.43 1.0 3.0 2.0 -2.4 N

CLERMONT 7S, FL 28 27 81 45 70 4.82 3.0 4.0 3.5 -1.3 N

DE SOTO CITY, FL 27 22 81 31 73 2.22 1.0 2.0 1.5 -0.7 N

BARTOW, FL 27 54 81 51 74 1.79 0.1 2.0 1.1 -0.7 Y

LISBON, FL 28 52 81 47 86 4.21 3.0 5.0 4.0 -0.2 Y

MOORE HAVEN LOCK 1, FL 26 50 81 05 92 3.33 1.0 3.0 2.0 -1.3 N

BUSHNELL 2E, FL 28 40 82 05 94 2.35 1.0 2.0 1.5 -0.9 N

ARCADIA, FL 27 14 81 51 95 2.98 1.0 2.0 1.5 -1.5 N

CLEWISTON US ENGINEERS, FL 26 45 80 55 95 4.12 1.0 3.0 2.0 -2.1 N

ST. LEO, FL 28 20 82 16 99 1.83 0.1 2.0 1.1 -0.8 Y

BELLE GLADE EXP STN, FL 26 39 80 38 101 5.68 3.0 5.0 4.0 -1.7 N

WEST PALM BEACH WSO, FL 26 41 80 07 104 7.34 5.0 8.0 6.5 -0.8 Y

CRESCENT CITY, FL 29 26 81 31 105 3.95 2.0 4.0 3.0 -1.0 Y

LOXAHATCHEE NWR, FL 26 30 80 13 114 10.93 5.0 7.0 6.0 -4.9 N

OCALA, FL 29 12 82 05 114 1.81 0.1 1.0 0.6 -1.3 N

TAMPA WSCMO AIRPORT, FL 27 58 82 32 114 0.19 0.0 1.0 0.5 0.3 Y

PUNTA GORDA 4ESE, FL 26 55 82 00 116 1.16 0.1 1.0 0.6 -0.6 N

BRADENTON, FL 27 27 82 28 119 0.98 0.1 1.0 0.6 -0.4 Y

IMMOKALEE 3NNW, FL 26 28 81 26 123 3.76 1.0 2.0 1.5 -2.3 N

FORT MYERS FAA/AP, FL 26 36 81 52 128 1.77 0.1 1.0 0.6 -1.2 N

VENICE, FL 27 06 82 26 129 0.68 0.1 1.0 0.6 -0.1 Y

 

 averages: 4.37 2.9 -1.5

 NEXRAD est. as % of measured: 65%

 distance/difference correlation: -0.41

% of stns. with prec. in est. range: 28%
TABLE 4 MOBILE WSMO, LA (KMOB) May 8-13, 1995

 lat. long (mi.) prec range of avg. avg.-

station de mi de mi dist tot. estimates est. obs. ir

MOBILE WSO AIRPORT, AL 30 41 88 15 0 10.42 8.0 10.0 9.0 -1.4 N

BAY MINETTE 3NNW, AL 30 55 87 47 31 10.73 10.0 13.0 11.5 0.8 Y

BILOXI, MS 30 23 88 59 48 14.39 10.0 15.0 12.5 -1.9 Y

WIGGINS, MS 30 52 89 08 54 5.44 6.0 8.0 7.0 1.6 N

GULFPORT NAVAL STATION, MS 30 23 89 08 56 8.93 10.0 13.0 11.5 2.6 N

HATTIESBURG, MS 31 19 89 18 76 2.71 3.0 6.0 4.5 1.8 N

POPLARVILLE EXP STN, MS 30 51 89 33 78 5.35 6.0 10.0 8.0 2.7 N

BAY ST. LOUIS NASA, MS 30 22 89 35 82 16.91 17.0 21.0 19.0 2.1 N

PICAYUNE, MS 30 31 89 42 87 21.94 17.0 23.0 20.0 -1.9 Y

SLIDELL WSFO, LA 30 15 89 46 95 23.10 17.0 21.0 19.0 -4.1 N

SLIDELL WSMO, LA 30 20 89 49 96 24.01 19.0 21.0 20.0 -4.0 N

ABITA SPRINGS FIRE TOWER, LA 30 26 90 03 108 24.99 19.0 23.0 21.0 -4.0 N

COVINGTON 4NNW, LA 30 32 90 07 111 11.35 10.0 17.0 13.5 2.2 Y

CHALMETTE, LA 29 58 89 58 114 3.87 10.0 15.0 12.5 8.6 N

FRANKLINTON 5SW, LA 30 47 90 13 117 6.91 3.0 8.0 5.5 -1.4 Y

PRENTISS 3NW, MS 31 37 89 55 118 1.74 1.5 6.0 3.8 2.0 Y

BURAS, LA 29 20 89 31 120 1.00 0.5 1.5 1.0 0.0 Y

METAIRIE, LA 29 59 90 08 122 16.71 10.0 15.0 12.5 -4.2 N

MONTICELLO, MS 31 33 90 06 125 1.95 1.5 3.0 2.3 0.3 Y

HAMMOND 5E, LA 30 30 90 22 127 5.90 3.0 6.0 4.5 -1.4 Y

PONCHATOULA 4SE, LA 30 25 90 23 128 8.53 6.0 13.0 9.5 1.0 Y

NEW ORLEANS WSCMO, LA 29 59 90 15 129 15.38 10.0 15.0 12.5 -2.9 N

AMITE, LA 30 42 90 32 136 8.46 6.0 8.0 7.0 -1.5 N

KENTWOOD, LA 30 56 90 31 136 2.70 1.0 3.0 2.0 -0.7 Y

 

 averages: 10.56 10.4 -0.2

 NEXRAD est. as % of measured: 98%

 distance/difference correlation: 0.09

 % of stns. with prec. in est. range: 46%
TABLE 5 SLIDELL WSMO, LA (KLIX) May 8-13, 1995

 lat. long (mi.) prec range of avg. avg.-

station de mi de mi dist tot. estimates est. obs. ir

SLIDELL WSMO, LA 30 20 89 49 0 24.01 8.0 10.0 9.0 -15.0 N

SLIDELL WSFO, LA 30 15 89 46 6 23.10 5.0 8.0 6.5 -16.6 N

ABITA SPRINGS FIRE TOWER, LA 30 26 90 03 14 24.99 8.0 12.0 10.0 -15.0 N

BAY ST. LOUIS NASA, MS 30 22 89 35 14 16.91 4.0 8.0 6.0 -10.9 N

PICAYUNE, MS 30 31 89 42 14 21.94 8.0 12.0 10.0 -11.9 N

COVINGTON 4NNW, LA 30 32 90 07 22 11.35 6.0 10.0 8.0 -3.4 N

CHALMETTE, LA 29 58 89 58 26 3.87 5.0 8.0 6.5 2.6 N

METAIRIE, LA 29 59 90 08 30 16.71 6.0 10.0 8.0 -8.7 N

PONCHATOULA 4SE, LA 30 25 90 23 33 8.53 5.0 10.0 7.5 -1.0 Y

HAMMOND 5E, LA 30 30 90 22 34 5.90 4.0 5.0 4.5 -1.4 N

NEW ORLEANS WSCMO, LA 29 59 90 15 35 15.38 8.0 12.0 10.0 -5.4 N

FRANKLINTON 5SW, LA 30 47 90 13 38 6.91 3.0 6.0 4.5 -2.4 N

POPLARVILLE EXP STN, MS 30 51 89 33 39 5.35 3.0 6.0 4.5 -0.9 Y

GULFPORT NAVAL STATION, MS 30 23 89 08 41 8.93 5.0 6.0 5.5 -3.4 N

AMITE, LA 30 42 90 32 49 8.46 4.0 6.0 5.0 -3.5 N

BILOXI, MS 30 23 88 59 50 14.39 6.0 8.0 7.0 -7.4 N

RESERVE 4WNW, LA 30 05 90 37 50 11.70 6.0 10.0 8.0 -3.7 N

WIGGINS, MS 30 52 89 08 55 5.44 2.5 4.0 3.3 -2.2 N

LIVINGSTON, LA 30 30 90 45 56 6.19 3.0 5.0 4.0 -2.2 N

KENTWOOD, LA 30 56 90 31 58 2.70 1.5 2.5 2.0 -0.7 N

GONZALES, LA 30 14 90 55 65 6.55 4.0 5.0 4.5 -2.1 N

THIBODAUX 3ESE, LA 29 46 90 47 69 13.74 5.0 8.0 6.5 -7.2 N

BURAS, LA 29 20 89 31 71 1.00 0.6 1.5 1.1 0.1 Y

DONALDSONVILLE 4SW, LA 30 04 91 02 74 6.83 8.0 10.0 9.0 2.2 N

HATTIESBURG, MS 31 19 89 18 74 2.71 1.5 2.0 1.8 -1.0 N

HOUMA, LA 29 35 90 44 75 2.30 2.0 4.0 3.0 0.7 Y

ST. GABRIEL, LA 30 16 91 06 76 3.68 3.0 6.0 4.5 0.8 Y

BATON ROUGE WSO AP, LA 30 32 91 08 79 4.97 3.0 4.0 3.5 -1.5 N

PLAQUEMINE 2N, LA 30 19 91 14 83 3.98 2.0 4.0 3.0 -1.0 Y

MONTICELLO, MS 31 33 90 06 85 1.95 1.0 2.5 1.8 -0.2 Y

PRENTISS 3NW, MS 31 37 89 55 88 1.74 1.0 2.0 1.5 -0.2 Y

BAYOU SORREL LOCK, LA 30 08 91 19 90 3.86 2.5 4.0 3.3 -0.6 Y

MORGAN CITY, LA 29 41 91 11 92 12.18 5.0 8.0 6.5 -5.7 N

MOBILE WSO AIRPORT, AL 30 41 88 15 96 10.42 4.0 8.0 6.0 -4.4 N

ST. FRANCISVILLE, LA 30 46 91 23 97 4.09 1.0 2.0 1.5 -2.6 N

FRANKLIN 3NW, LA 29 49 91 33 109 6.14 4.0 6.0 5.0 -1.1 N

NEW IBERIA, LA 29 59 91 47 119 3.98 2.0 4.0 3.0 -1.0 Y

BAY MINETTE 3NNW, AL 30 55 87 47 127 10.73 3.0 5.0 4.0 -6.7 N

LAFAYETTE FCWOS, LA 30 12 91 59 129 5.36 1.5 3.0 2.3 -3.1 N

LIBERTY 5W, MS 31 10 90 53 134 1.85 1.5 3.0 2.3 0.4 Y

 

 averages: 8.77 5.1 -3.7

 NEXRAD est. as % of measured: 58%

 distance/difference correlation: -0.57

 % of stns. with prec. in est. range: 28%
TABLE 6 COLUMBIA, SC (KCAE) August 23-29, 1995

 lat. long (mi.) prec range of avg. avg.-

station de mi de mi dist tot. estimates est. obs. ir

COLUMBIA UNIV OF SC, SC 33 59 81 01 6 6.03 1.5 5.0 3.3 -2.8 N

BATESBURG, SC 33 54 81 32 23 5.10 2.0 4.0 3.0 -2.1 N

WINNSBORO, SC 34 22 81 05 28 4.32 1.5 2.5 2.0 -2.3 N

ORANGEBURG 2, SC 33 30 80 52 34 9.69 5.0 8.0 6.5 -3.2 N

NEWBERRY, SC 34 17 81 37 36 5.14 0.6 2.5 1.6 -3.6 N

AIKEN 4NE, SC 33 36 81 41 40 4.64 2.5 4.0 3.3 -1.4 N

MANNING, SC 33 41 80 14 54 4.55 2.0 4.0 3.0 -1.6 N

BRANCHVILLE 6S, SC 33 11 80 48 55 11.30 3.0 4.0 3.5 -7.8 N

MCCORMICK 9E, SC 33 55 82 09 59 6.17 2.5 3.0 2.8 -3.4 N

LOCKHART, SC 34 47 81 28 60 7.18 1.5 2.5 2.0 -5.2 N

AUGUSTA WSO AIRPORT, GA 33 22 81 58 63 3.66 1.5 2.5 2.0 -1.7 N

LAURENS, SC 34 30 82 02 64 8.26 1.5 4.0 2.8 -5.5 N

PAGELAND, SC 34 45 80 24 68 3.33 1.0 3.0 2.0 -1.3 N

FORT MILL 4NW, SC 35 01 81 00 74 7.02 2.0 4.0 3.0 -4.0 N

KINGSTREE 1SE, SC 33 39 79 49 77 6.95 4.0 6.0 5.0 -2.0 N

FLORENCE FAA AP, SC 34 11 79 43 81 4.99 3.0 5.0 4.0 -1.0 Y

CHARLOTTE WSO ARPT, NC 35 13 80 56 88 6.13 1.0 4.0 2.5 -3.6 N

MILLEN 4N, GA 32 52 81 58 89 5.64 2.5 3.0 2.8 -2.9 N

GRNVL/SPART WSO AP, SC 34 54 82 13 90 14.85 4.0 6.0 5.0 -9.9 N

WADESBORO, NC 34 58 80 04 92 4.27 1.5 3.0 2.3 -2.0 N

CHESNEE 7WSW, SC 35 07 81 58 93 8.20 2.0 3.0 2.5 -5.7 N

CHARLESTON WSO AP, SC 32 54 80 02 95 9.59 4.0 8.0 6.0 -3.6 N

LOUISVILLE 1E, GA 33 01 82 24 97 6.61 3.0 4.0 3.5 -3.1 N

RIDGELAND 5NE, SC 32 32 80 54 98 7.09 4.0 6.0 5.0 -2.1 N

FOREST CITY 6SW, NC 35 16 81 56 102 6.05 1.5 2.5 2.0 -4.1 N

DILLON, SC 34 25 79 23 104 6.79 2.0 4.0 3.0 -3.8 N

CLEMSON UNIV, SC 34 41 82 49 109 5.70 0.3 1.0 0.7 -5.1 N

LAURINBURG, NC 34 45 79 27 110 5.60 2.0 2.5 2.3 -3.4 N

MCCLELLANVILLE, SC 33 05 79 29 111 8.69 3.0 6.0 4.5 -4.2 N

EDISTO ISLAND 3SW, SC 32 28 80 20 111 8.19 2.5 4.0 3.3 -4.9 N

LEXINGTON 1NW, GA 33 53 83 08 115 4.77 0.3 1.0 0.7 -4.1 N

SWAINSBORO, GA 32 35 82 22 118 9.08 2.5 4.0 3.3 -5.8 N

CONWAY, SC 33 50 79 03 118 9.19 4.0 6.0 5.0 -4.2 N

HILTON HEAD, SC 32 13 80 45 121 15.13 4.0 6.0 5.0 -10.1 N

CARNESVILLE 4N, GA 34 27 83 14 125 5.26 0.3 1.0 0.7 -4.6 N

SAVANNAH WSO AIRPORT, GA 32 08 81 12 125 12.37 4.0 5.0 4.5 -7.9 N

SALISBURY, NC 35 41 80 29 125 5.35 0.3 1.0 0.7 -4.7 N

ROSMAN, NC 35 09 82 49 127 5.74 1.0 1.5 1.3 -4.5 N

MORGANTON, NC 35 45 81 41 128 2.87 0.6 1.0 0.8 -2.1 N

LUMBERTON 3SE, NC 34 37 78 59 130 3.60 2.0 2.5 2.3 -1.4 N

SWANNANOA 2SSE, NC 35 34 82 23 132 6.67 2.0 3.0 2.5 -4.2 N

 averages: 6.87 3.0 -3.9

 NEXRAD est. as % of measured: 43%

 distance/difference correlation: 0.31

% of stns. with prec. in est. range: 2%
 

 

 
 
 

 
 

 
 
 
 
 
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