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Fall Weather Pattern Arrives

Rain and much cooler temperatures behind a cold front will bring a feeling of fall to the east coast today. In addition, an active fall storm pattern developing in the Pacific Northwest this week will bring areas of heavy rains, and very high elevations could receive heavy snow. Wetting rains to the valley floors will spread south Thu and Fri into northern California,where active fires continue. Read More >

Mesoscale Discussion #863 issued at 1620 UTC
MESOSCALE DISCUSSION 0863
   NWS STORM PREDICTION CENTER NORMAN OK
   1120 AM CDT SUN MAY 14 2006
   
   AREAS AFFECTED...PORTIONS VA...NC...NRN SC...SERN WV.
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 141620Z - 141815Z
   
   SEVERE POTENTIAL IS EXPECTED TO BECOME LESS ISOLATED AND BETTER
   ORGANIZED THROUGH AT LEAST 20Z.  SEVERE TSTM WW WILL BE ISSUED
   SHORTLY FOR WESTERN PORTION OF THIS AREA.  WW SUBSEQUENTLY MAY BE
   REQUIRED FOR SOME PORTION OF THIS REGION FARTHER E AS WELL.
   
   16Z SFC ANALYSIS SHOWS DIFFERENTIAL HEATING BOUNDARY -- ASSOCIATED
   WITH BAND OF WAA RELATED CONVECTION NOW MOVING NEWD ACROSS ERN
   VA/EXTREME NERN NC -- ANALYZED FROM SRN PAMLICO SOUND WNWWD ACROSS
   WAKE COUNTY TO VICINITY DAN.  THIS BOUNDARY SHOULD MIX/MOVE NEWD
   15-25 KT WITH ASSOCIATED DESTABILIZATION SPREADING INTO
   S-CENTRAL/SERN VA AND NERN NC. RELATIVELY STEEP MIDLEVEL LAPSE
   RATES OF AROUND 7-8 DEG C/KM -- EVIDENT IN MORNING GSO RAOB -- ARE
   EXPECTED TO CONTINUE AFFECTING WRN NC...WRN VA AND SERN WV...AND
   SHIFT NEWD ACROSS PORTIONS CENTRAL NC THROUGH CENTRAL VA.  THIS WILL
   COMBINE WITH SFC HEATING TO FURTHER REDUCE CINH AND BOOST MLCAPES TO
   AROUND 1000 J/KG FROM W-CENTRAL VA SSWWD TO EXTREME N-CENTRAL SC. 
   ALTHOUGH LAPSE RATES WEAKEN WITH EWD EXTENT...STRONGER SFC HEATING
   WILL CONTRIBUTE TO SIMILAR BUOYANCY OVER CENTRAL/SRN NC AND
   S-CENTRAL VA...SW OF BOUNDARY. FAVORABLE DEEP-LAYER VERTICAL SHEAR
   PROFILES -- I.E., 40-50 KT 0-6 KM SHEAR INCREASING WITH SWD EXTENT
   BENEATH MIDLEVEL SPEED MAX...WILL SUPPORT SVR POTENTIAL.
   
   ..EDWARDS.. 05/14/2006
   
   
   ATTN...WFO...AKQ...MHX...LWX...RAH...ILM...RNK...RLX...CAE...GSP...MRX...
   
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