Heavy to excessive rainfall may lead to flooding Wednesday over southwest Pennsylvania into northern West Virginia, and western Maryland. Flood Watches have been issued. An extended period of hot weather will continue for parts of coastal southern California including Los Angeles through Thursday. Heat Advisories remain in effect. Read More >
![]() 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 |