Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 050523
FFGMPD
MOZ000-ARZ000-OKZ000-KSZ000-NEZ000-051121-

MESOSCALE PRECIPITATION DISCUSSION 0423
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
122 AM EDT WED AUG 05 2015

AREAS AFFECTED...EASTERN KS, SOUTHWEST MO, & VICINITY

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

VALID 050521Z - 051121Z

SUMMARY...INCREASING LOW-LEVEL INFLOW OVER A WEAK THERMAL BOUNDARY
IS EXPECTED TO INCREASE THUNDERSTORM COVERAGE AND INTENSITY AFTER
06Z.  FLASH FLOODING IS POSSIBLE.

DISCUSSION...THUNDERSTORMS NEAR THE KS/MO BORDER AND SOUTHWEST MO
HAVE DEVELOPED NEAR A PAIR OF SHORTWAVES ALOFT WELL-ELEVATED OVER
A WEAK THERMAL BOUNDARY/INSTABILITY GRADIENT NEAR THE BOUNDARY`S
850 HPA LOCATION.  INFLOW AT 850 HPA IS 20-25 KTS INTO THE REGION
PER VAD WIND PROFILES, IMPORTING MUCAPES OF 1000-3000 J/KG INTO
THE REGION.  PRECIPITABLE WATER VALUES OF 1.75-2" LIE HERE PER GPS
INFORMATION.

THE LOW-LEVEL JET, PERHAPS AIDED BY THE SHORTWAVE ADVANCING ACROSS
NE/KS, IS EXPECTED TO INCREASE AFTER 06Z, WITH A BROAD AREA OF 850
HPA WINDS OF 25-35 KTS FUNNELING INTO THE REGION, WHICH IS 5-10
KNOTS ABOVE THE MEAN 850-400 HPA WIND.  THE FLOW AT THAT LEVEL IS
GENTLY CONVERGENT, WHICH COULD HELP PRECIPITATION EFFICIENCY.  A
MOVEMENT TO THE SOUTHEAST TO EAST-SOUTHEAST AT ~20 KTS IS
INDICATED BY FORWARD PROPAGATING CONVECTIVE VECTORS -- CELL
TRAINING IS THE MAIN FLASH FLOOD THREAT.  THE MESOSCALE QPF
GUIDANCE SHOWS GOOD AGREEMENT, SHOWING LOCAL MAXIMA IN THE 3-5"
RANGE OVER PORTIONS OF THIS AREA.  BELIEVE THEIR AMOUNTS FROM THE
CENTRAL MO/AR BORDER EASTWARD ARE LIKELY TOO HIGH DUE TO THE
AVAILABLE INSTABILITY AND RECENT RAP MUCAPE FORECASTS.  RAINFALL
COULD FALL QUICKLY, AS AVAILABLE MOISTURE WOULD ALLOW FOR HOURLY
RAIN RATES UP TO 2.25".  AS THE COVERAGE ACROSS THE REGION IS NOT
EXPECTED TO BE SOLID, AND FLASH FLOOD GUIDANCE VALUES ARE
MODERATELY HIGH, CHOSE THE POSSIBLE CATEGORY OVER LIKELY.

ROTH

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

ATTN...WFO...DDC...EAX...GID...ICT...LZK...SGF...TOP...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...

LAT...LON   40119929 39959734 38949469 37709239 36189257
            35959377 37129636 39179922


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