Flash Flood Guidance
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000
AWUS01 KWNH 310913
FFGMPD
NCZ000-SCZ000-311506-

MESOSCALE PRECIPITATION DISCUSSION 0474
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
512 AM EDT MON AUG 31 2015

AREAS AFFECTED...EASTERN CAROLINAS

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

VALID 310906Z - 311506Z

SUMMARY...FLASH FLOODING WILL BECOME INCREASINGLY POSSIBLE ACROSS
THE EASTERN CAROLINAS 12-18Z.

DISCUSSION...MORE WIDESPREAD AND DEEPER CONVECTION CONTINUES TO
SLOWLY INCREASE IN VICINITY OF A WEAK STATIONARY FRONT BETWEEN
CHARLOTTE AND SAVANNAH...AS WELL AS ALONG A DEVELOPING STATIONARY
FRONT ALONG THE SC COAST.  THERMODYNAMIC AND KINEMATIC TRENDS
INCLUDING POSITIVE INCREASES IN THETA E/CAPE/ECHO TOPS/RAIN
RATE/AND ONSHORE FLOW ARE SUPPORTING THE INCREASED CONVECTIVE
DEVELOPMENT.

MANY OF THE HI-RES SOLUTIONS AGREE IN ALLOWING THE ONSHORE FLOW TO
COMBINE WITH SOME DIABATIC HEATING AFTER SUNRISE TO FURTHER
DESTABILIZE THE ENVIRONMENT IN VICINITY OF THE FRONTAL BOUNDARIES
AS WELL AS AHEAD OF THE MESOLOW NEAR CHARLOTTE AND NORTH OF ITS
ACCOMPANYING WARM FRONT TO SUPPORT AN EXPANSION OF THE CURRENT
CONVECTION.

THE 00Z NAM/00Z GFS AND EARLIER RUNS OF THE RAP/HRRR SEEM TO
CAPTURE THE CURRENT EVOLUTION REASONABLY WELL.  WHILE IT MAY TAKE
SEVERAL HOURS FOR THE RAIN RATES TO INCREASE AND ANTECEDENT
CONDITIONS TO WORSEN TO SUPPORT FLASH FLOODING...THE DEPTH OF
MOISTURE WITH PW VALUES OF 1.9 TO 2.25 INCHES AS WELL AS NEARLY
UNIDIRECTIONAL FLOW NEAR THE STATIONARY FRONTS AND VEERING WINDS
NORTH OF THE WARM FRONT PROVIDE FAVORABLE CONDITIONS FOR RAIN TO
POSSIBLY EXCEED GUIDANCE BETWEEN 12-18Z.

JAMES

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

ATTN...WFO...AKQ...CAE...CHS...ILM...MHX...RAH...

ATTN...RFC...SERFC...

LAT...LON   36297794 35707642 34587675 33797796 32717949
            32048074 32338095 33298043 34068014 35088012
            35887949



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