Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 270339
FFGMPD
ILZ000-MOZ000-IAZ000-270800-

MESOSCALE PRECIPITATION DISCUSSION 0608
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1139 PM EDT FRI AUG 26 2016

AREAS AFFECTED...NORTHEAST MO...WESTERN/CENTRAL IL

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 270335Z - 270800Z

SUMMARY...EXPANDING AREA OF HEAVY SHOWERS AND THUNDERSTORMS WILL
FOSTER INCREASING POTENTIAL FOR FLASH FLOODING OVERNIGHT.

DISCUSSION...HEAVY SHOWERS AND THUNDERSTORMS ARE DEVELOPING AND
EXPANDING IN COVERAGE NORTH OF A STATIONARY FRONT DRAPED ACROSS
THE MID MS AND OH VALLEYS. THE APPROACH OF A SHORTWAVE TROUGH AND
ASSOCIATED WAVE OF LOW PRESSURE ALONG THE AFOREMENTIONED FRONT
WILL ALLOW CONVECTION TO CONTINUE TO ORGANIZE AND EXPAND IN
COVERAGE OVERNIGHT AS LOW LEVEL WARM ADVECTION INCREASES AND HELPS
TOO POOL DEEPER MOISTURE AND INSTABILITY FARTHER NORTH.

RAINFALL RATES OF AS MUCH AS 2.5 INCHES/HR ARE EXPECTED WITH
STRONGER CONVECTIVE CORES CLOSER TO THE FRONT...BUT GIVEN A RATHER
FAVORABLE SET-UP FOR TRAINING CELLS...LOCALLY VERY HEAVY RAINFALL
TOTALS WILL BE POSSIBLE. THIS WILL ESPECIALLY BE THE CASE ALONG
AND ADJACENT A LINE FROM JUST NORTHWEST OF COLUMBIA MO...TO QUINCY
AND GALESBURG IL.

HIRES MODEL GUIDANCE IS NOT DOING WELL WITH THE CURRENT CONVECTIVE
EXPANSION OVER NORTH-CENTRAL MO AND INTO NORTHWEST IL...BUT THE
EXPECTATION BASED ON COOLING CLOUD TOPS AND INCREASING LARGE SCALE
ASCENT IS FOR MORE ORGANIZED CONVECTION WITH HEAVY RAINFALL.

EXPECT RAINFALL AMOUNTS OF UP TO AS MUCH AS 3 TO 5 INCHES THROUGH
08Z...AND GIVEN THE LOCALLY WET ANTECEDENT CONDITIONS...FLASH
FLOODING IS LIKELY.

ORRISON

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

ATTN...WFO...DMX...DVN...EAX...ILX...LOT...LSX...

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

LAT...LON   41588981 41408909 40368943 39239111 38819206
            38709302 38729341 38909367 39459244 39899195
            40249181 40649222 41069129



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