Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 041118
FFGMPD
NEZ000-SDZ000-041530-

MESOSCALE PRECIPITATION DISCUSSION 0419
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
718 AM EDT TUE AUG 04 2015

AREAS AFFECTED...SOUTHWEST SD TO NORTH CENTRAL NEB

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 041117Z - 041530Z

SUMMARY...HEAVY RAINFALL OVER PARTS OF SOUTHWEST SD AND NORTHERN
NEB WILL GRADUALLY BE TAPERING OFF THROUGH 15Z...WITH A
CORRESPONDING DECREASING IN FLASH FLOODING WITH TIME.

DISCUSSION...ONGOING CONVECTION WILL GRADUALLY TAPER OFF DURING
THE MORNING WITH AN OVERALL DECREASE IN HEAVY RAINFALL AND FLASH
FLOODING THREAT AS THE LOW LEVEL BEGINS TO DIMINISH.  RADAR
IMAGERY STILL SHOWED SOME CONVECTION FORMING OVER PARTS OF
SOUTHWEST SD...AND ONE HOUR PRECIPITATION VALUES AS OF 11Z WERE
STILL RUNNING AS HIGH AS 1 TO 1.5 INCHES IN A FEW SPOTS.
HOWEVER...IR SATELLITE IMAGERY WAS ALREADY SHOWING CLOUD TOP TEMPS
WERE WARMING ALONG THE ENTIRE LINE OF CONVECTION...AND THE HIGH
RESOLUTION MODELS INCLUDING THE RAP WERE SHOWING LOW LEVEL WINDS
WEAKENING AND PW VALUES DROPPING.  THE LATEST SSEO MEAN ALSO
PICKED UP ON THE IDEA OF WANING CONVECTION THROUGH 15Z OR SO WITH
ONE HOUR NEIGHBORHOOD PROBABILITIES OF RAFL EXCEEDING FFG
INITIALLY STARTING AROUND 50 PCT AND DROPPING THROUGH THE MORNING.

AS A RESULT...THINK THERE WILL CONTINUE TO BE A LOCALIZED THREAT
FOR FLASH FLOODING...ESPECIALLY IN AREAS WHICH ALREADY RECEIVED
HEAVY RAINFALL OVERNIGHT...BEFORE THE THREAT DECREASES LATER THIS
MORNING.

BANN

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...ABR...FSD...LBF...OAX...UNR...

ATTN...RFC...MBRFC...

LAT...LON   44590054 43839908 42649817 42129871 42750001
            43640084 44260118


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