This is why we upgraded our radar to dual-pol!

Training thunderstorms formed along an outflow boundary Friday night and dropped an incredible amount of rainfall to portions of our forecast area. A swath through the central portion of our county warning area saw between 2 to 5 inches of rainfall with a few locations near 5.5 inches!  This map shows how much rainfall bell between 9 am Friday and 9 am Saturday.

 

 

What we found most interesting about this event was regarding the storm total precipitation estimation done by our radar.  The new dual pol precipitation estimation was virtually spot on!  The old (legacy) method of precipitation estimation was underestimating totals by as much as half.

 

Legacy Storm Total Precipitation estimation

    

 

Dual Pol Storm Total Precipitation Estimation

 

The legacy product estimated rainfall totals of 2 inches or greater anywhere the colors are green and 3 to 3.5 inches where the colors are yellow.  The dual pol estimated rainfall was 4 inches or greater everywhere there is blue and 5 inches or greater everywhere the image is yellow. When comparing the dual pol estimation to the observed precipitation map, they show almost identical amounts!

 

The map below shows contours of the dual-pol precipitation estimation with actual rainfall amounts overlaid as thumbtacks.  The accuracy of the dual-pol estimation is astonishing!

 

 

 

Here is a list of the greatest 24 hour rainfall amounts from around the area:

...LOCATION... TIME Amount
3 NE FORT WAYNE (ALLEN IN) (COCORAHS) 700 AM 5.27 IN
1 ESE WALLEN (ALLEN IN) (COCORAHS) 800 AM 4.84 IN
3 ENE WALLEN (ALLEN IN) (COCORAHS) 1000 AM 4.77 IN
WARSAW 5SW (KOSCIUSKO IN) (COOP) 900 AM 4.75 IN
1 NNE COLUMBIA CITY (WHITLEY IN) 700 AM 4.73 IN
1 E WINONA LAKE (KOSCIUSKO IN) 800 AM 4.7 IN
BRENTWOOD ELEMENTARY SCHOOL - CSO 900 AM 4.65 IN
1 NNE WINONA LAKE (KOSCIUSKO IN) 730 AM 4.64 IN
MAUMEE RIVER AT ANTHONY BLVD (ALLEN IN) 900 AM 4.58 IN
1 NNW WARSAW (KOSCIUSKO IN) (COCORAHS) 700 AM 4.44 IN
SPY RUN AT FRANKE PARK (ALLEN IN) 900 AM 4.36 IN
PRICE ELEMENTARY SCHOOL -  CSO 900 AM 4.25 IN
1 N ROLLING HILLS (ALLEN IN) (COCORAHS) 800 AM 4.2 IN
CITY/COUNTY BUILDING (ALLEN IN) (UCOOP) 900 AM 4.15 IN
GETZ ROAD FIRE STATION (WHITLEY IN) 900 AM 4.14 IN
ROCHESTER (FULTON IN) (770 FT)(COOP) 700 AM 4.13 IN
FAIRFIELD ELEMENTARY SCHOOL - CSO 900 AM 4.07 IN
STUDY ELEMENTARY SCHOOL - CSO 900 AM 4.07 IN
BUNCHE ELEMENTARY SCHOOL - CSO 900 AM 3.95 IN
4 W LEO-CEDARVILLE (ALLEN IN) 800 AM 3.74 IN
3 ESE HUNTERTOWN (ALLEN IN) (COCORAHS) 700 AM 3.71 IN
ADAMS ELEMENTARY SCHOOL - CSO 900 AM 3.63 IN
MAUMEE RIVER AT COLSEUM BLVD IN FORT WA 900 AM 3.62 IN
BELLE VISTA BRIDGE (ALLEN IN) (UCOOP) 900 AM 3.37 IN
HARRISON HILL ELEMENTARY SCHOOL - CSO 900 AM 3.36 IN
1 SSW OSWEGO (KOSCIUSKO IN) (COCORAHS) 700 AM 3.34 IN
DUPONT LIBRARY - CSO (ALLEN IN) (UCOOP) 900 AM 3.33 IN
HOMESTEAD/LIBERTY MILLS FIRE STATION 900 AM 3.23 IN
IRWIN ELEMENTARY SCHOOL - CSO 900 AM 3.21 IN
AVILLA 3SW (NOBLE IN) (990 FT)(COOP) 900 AM 3.18 IN
NORTHERN INDIANA WFO (KOSCIUSKO IN) 800 AM 2.97 IN
2 N NORTH WEBSTER (KOSCIUSKO IN) 800 AM 2.9 IN
WOODBURN 3N (ALLEN IN) (710 FT)(COOP) 700 AM 2.9 IN
2 W AVILLA (NOBLE IN) (COCORAHS) 700 AM 2.8 IN
1 E BIG LAKE (NOBLE IN) (COCORAHS) 700 AM 2.79 IN
GARRETT (DE KALB IN) (880 FT)(COOP) 700 AM 2.54 IN
HICKSVILLE (DEFIANCE OH) (790 FT)(COOP) 645 AM 2.52 IN
FISH CRK AT HAMILTON, IN. (STEUBEN IN) 1045 AM 2.44 IN
HUDSON (STEUBEN IN) (988 FT)(COCORAHS) 900 AM 2.42 IN
IRENE BYCON SANITARIUM (ALLEN IN) 900 AM 2.39 IN
TIPPECANOE RIVER AT NORWAY (WHITE IN) 1045 AM 2.39 IN
2 E HAMILTON (STEUBEN IN) (COCORAHS) 700 AM 2.37 IN
STRYKER (WILLIAMS OH) (700 FT)(COOP) 700 AM 2.11 IN
2 N AUBURN (DE KALB IN) (COCORAHS) 800 AM 2.1 IN
1 NE LAKE WAWASEE (KOSCIUSKO IN) 800 AM 2.01 IN
1 E LOGANSPORT (CASS IN) (COCORAHS) 700 AM 2 IN

 OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING
EQUIPMENT AND EXPOSURES. NOT ALL DATA LISTED IS CONSIDERED OFFICIAL. THE
NATIONAL WEATHER SERVICE THANKS ITS PRIVATE AND PUBLIC PARTNERS FOR
PROVIDING US WITH THIS DATA.

 

A few pictures of the flooding can be seen on our Facebook page and our Twitter @NWSIWX.


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