Flash Flood Guidance
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402
AWUS01 KWNH 271630
FFGMPD
TXZ000-272029-

MESOSCALE PRECIPITATION DISCUSSION 0249
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1230 PM EDT FRI MAY 27 2016

AREAS AFFECTED......EAST TEXAS...

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

VALID 271629Z - 272029Z

SUMMARY...WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUE TO
PROPAGATE SLOWLY SOUTHWARD INTO AN AREA THAT HAD RECEIVED VERY
HEAVY RAINFALL OVER THE PAST 24 HOURS. ADDITIONAL FLASH FLOODING
IS LIKELY.

DISCUSSION...WHILE NOT AS STRONG AS OVERNIGHT... SSW LOW-LEVEL
INFLOW BETWEEN 30-35 KTS IS MORE THAN SUFFICIENT TO MAINTAIN
SUFFICIENT STORM SCALE ORGANIZATION OF THE CONVECTION IN EAST
TEXAS. WHAT WAS ORIGINALLY A DEWPOINT BOUNDARY OVERNIGHT IS NOW A
DISCRETE STATIONARY DRAPED WITHIN THE OUTLOOK AREA...WITH
TEMPERATURES TO THE NORTH IN SHARP CONTRAST TO THE 80S FARTHER
SOUTH. PER THE LATEST TRENDS IN THE SPC
MESOANALYSIS...STRENGTHENING DEEP-LAYER INSTABILITY IS FEEDING
INTO THIS BOUNDARY FROM THE SOUTH...WITH MIXED-LAYER CAPES OF
2000-3000 J/KG NOTED WITH AN INCREASE OF 500-1000 J/KG OVER THE
PAST 3 HOURS. MEANWHILE...THE AIRMASS REMAINS QUITE RICH WITH
MOISTURE...WITH THE PWS BETWEEN 1.5 AND 2.0 INCHES AROUND 2-2.5
STANDARD DEVIATIONS ABOVE NORMAL.

SOME OF THE RECENT RUNS OF THE CAM GUIDANCE... IN PARTICULAR THE
HRRR...PARALLEL HRRR... EXPERIMENTAL HRRR...AND AND 12Z
NSSL-WRF...ALL SHOW THE STRONGER CORES PRODUCING 3 TO AS MUCH AS 8
INCHES OF RAIN LOCALLY AS THE CONVECTION EXPANDS SOUTHWARD INTO AN
AREA WITH ANTECEDENT WET SOILS AND LOW FFG.

HURLEY

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

ATTN...WFO...EWX...FWD...HGX...LCH...SHV...

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

LAT...LON   31629514 31189385 30319377 29649488 29349644
            29449754 30049798 30909675



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