Flash Flood Guidance
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000
AWUS01 KWNH 282229
FFGMPD
TXZ000-290130-

MESOSCALE PRECIPITATION DISCUSSION 0147
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
628 PM EDT THU MAY 28 2015

AREAS AFFECTED......WEST XT...

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

VALID 282230Z - 290130Z

SUMMARY..DEVELOPING CONVECTION AHEAD OF THE DRY LINE COULD PRODUCE
FLASH FLOODING BEFORE THE STORMS BEGIN TO ACCELERATE TO THE
SOUTHEAST THIS EVENING.

DISCUSSION...CONVECTION IS DEVELOPING AHEAD OF THE DRY LINE ON THE
INSTABILITY AND MOISTURE AXES. VISIBLE IMAGES SHOWED AGITATED
CUMULUS SOUTHWEST OF THE LARGER THUNDERSTORM COMPLEX NEAR KINK.
ADDITIONAL CONVECTION DEVELOPS ON THE SOUTHWEST FLANK OF THE
NORTHERN COMPLEX...HAVING PREFERENTIAL ACCESS TO MOISTURE ON THE
INCREASING LOW LEVEL SOUTHEAST FLOW.

KMAF RADAR INDICATED HOURLY RAINFALL RATES IN EXCESS OF 2
INCHES...BUT GIVEN THE SBCAPE VALUES OF 35OO TO 4500 J/KG...THESE
AMOUNTS ARE LIKELY HAIL CONTAMINATED. HOWEVER...THE STORMS ARE
EXPECTED TO RIDE THE PRECIPITABLE WATER GRADIENT AHEAD OF THE DRY
LINE LATE THIS AFTERNOON...AND TRAINING AND MERGING CELLS COULD
RESULT IN AN INCREASED FLASH FLOOD THREAT.

EVENTUALLY...THESE STORMS BECOME COLD POOLED DOMINATED...AND
ACCELERATE TO THE SOUTHEAST DURING THE EVENING HOURS. BEFORE THAT
TIME.. .THE LATEST HRRR SUGGESTS THAT LOCAL 2 INCH RAINFALL
AMOUNTS ARE POSSIBLE. THESE RAINFALL AMOUNTS COULD RESULT IN FLASH
FLOODING BEFORE THE STORMS ACCELERATE TO THE SOUTHEAST.

HAYES

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

ATTN...WFO...MAF...SJT...

ATTN...RFC...WGRFC...

LAT...LON   31560331 31540251 30290205 29080234 28400335
            28600417 28800425 29100435 29470438 29860438
            30230440 30360433 30100444 30360431 30600405




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