Epic Outbreak of Tornadoes Across the Southeast on 27-28 April 2011 Impacts Northeast Georgia and Western North Carolina

Mesoscale Discussion #0622 issued at 1651 UTC 27 April 2011

MESOSCALE DISCUSSION 0622
NWS STORM PREDICTION CENTER NORMAN OK
1151 AM CDT WED APR 27 2011
   
AREAS AFFECTED...MUCH OF SC...CNTRL/ERN NC...CNTRL/ERN VA
   
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
VALID 271651Z - 271815Z
   
PORTIONS OF SC...CNTRL/ERN NC...AND CNTRL/ERN VA WILL EXPERIENCE AN
INCREASE IN THUNDERSTORM COVERAGE DURING THE NEXT FEW HOURS. THIS
ACTIVITY WILL POSE A SVR WEATHER RISK...AND THE AREA WILL LIKELY
REQUIRE A WW ISSUANCE.
   
DEEP LAYER S-SWLY FLOW RESIDES ACROSS THE SERN ATLANTIC AND MID
ATLANTIC REGION...CHARACTERIZED BY 40 KT SLY LLJ OVERLAYED BY
STRENGTHENING SWLY MIDLEVEL FLOW /APPROACHING 40 KT/. IN
ADDITION...VERY MOIST BOUNDARY LAYER /SURFACE DEWPOINTS IN THE UPPER
60S TO LOW 70S/ COINCIDES WITH STRONG DAYTIME HEATING /TEMPERATURES
WARMING INTO THE 80S/. THE WARM/MOIST CONDITIONS ARE LEADING TO
RAPID DESTABILIZATION AND THUNDERSTORM INITIATION. GIVEN MLCAPE
VALUES FROM 1000-2000 J/KG...FAVORABLY STEEP LAPSE RATES...AND
STRENGTHENING VERTICAL WIND SHEAR PROFILES /EFFECTIVE SHEAR
INCREASING TO 35-50 KT...AND ENLARGING LOW-LEVEL HODOGRAPH
STRUCTURE/...THE THREAT FOR DAMAGING WINDS AND LARGE HAIL WILL EXIST
ACROSS THE AREA THIS AFTERNOON. IN ADDITION...A FEW TORNADOES WILL
ALSO BE POSSIBLE.
   
..GARNER.. 04/27/2011
   
   
ATTN...WFO...AKQ...MHX...LWX...RAH...ILM...RNK...CHS...CAE...
GSP...
   
LAT...LON   35658107 38147891 38127673 36527643 34697776 33018019
            33038123 34018169 35658107