MESO: Mesoscale Discussion 1226

ACUS11 KWNS 081742
SWOMCD
SPC MCD 081742
NCZ000-VAZ000-SCZ000-081845-

MESOSCALE DISCUSSION 1226
NWS STORM PREDICTION CENTER NORMAN OK
1242 PM CDT THU JUL 08 2010

AREAS AFFECTED...SERN VA...ERN NC...NERN SC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 081742Z - 081845Z

THREAT FOR DAMAGING DOWNBURST WINDS IN ADDITION TO MARGINALLY SEVERE
HAIL IS EXPECTED AS STORM DEVELOP OVER SERN VA...ERN NC...AND NERN
SC THIS AFTERNOON. IT IS UNCERTAIN WHETHER A WW WILL BE NEEDED...BUT
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

STRONG SURFACE HEATING IS OCCURRING ACROSS MUCH OF THE MID
ATLANTIC...WITH EARLY AFTERNOON TEMPERATURES ALL READY CLIMBING INTO
THE 80S AND 90S F. IN ADDITION...PLUME OF HIGHER MOISTURE
CONTENT...CHARACTERIZED BY PWAT VALUES NEAR 2 INCHES...AND SURFACE
DEWPOINTS IN THE LOW 70S F...IS SURGING WWD IN ADVANCE OF UPPER
DISTURBANCE LOCATED OFFSHORE. BOUNDARY LAYER DESTABILIZATION HAS
ALREADY REDUCED CINH TO NEAR ZERO...AND COMBINATION OF STRONG
HEATING AND MOIST LOW-LEVEL AIR MASS IS YIELDING STRONG INSTABILITY
ACROSS THE REGION...WITH MLCAPE VALUES AOA 2000 J/KG.

THUNDERSTORMS ARE FORECAST TO DEVELOP DURING THE NEXT SEVERAL HOURS
OVER SERN VA AND ERN NC...AND THEN MOVE SWD INTO NERN SC DURING THE
REMAINDER OF THE AFTERNOON. DEEP LAYER OF UNIDIRECTIONAL N-NELY
MID-UPPER LEVEL FLOW WILL FAVOR EFFECTIVE BULK SHEAR VALUES NEAR 35
KT...WHICH WILL BE SUPPORTIVE OF ORGANIZED MULTICELLS AND LINE
SEGMENTS. HOT/HUMID BOUNDARY LAYER...STEEP LOW-LEVEL LAPSE
RATES...AND STRONG INSTABILITY SUGGESTS THAT DAMAGING DOWNBURST
WINDS WILL BE THE PRIMARY SEVERE WEATHER THREAT.

..GARNER.. 07/08/2010

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...

LAT...LON 34627726 33387919 33957987 36547910 37467823 37577713
37067622 35727615 34627726

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