MESOSCALE DISCUSSION 2003
   NWS STORM PREDICTION CENTER NORMAN OK
   0159 PM CDT THU AUG 18 2011
   
   AREAS AFFECTED...PORTIONS OF WRN VA...WRN NC...NWRN SC...FAR NERN
   GA...FAR ERN TN
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 181859Z - 182100Z
   
   WHILE A FEW STORMS COULD PRODUCE GUSTY WINDS...THE OVERALL SVR
   THREAT WILL LIKELY REMAIN MINIMAL...THUS PRECLUDING THE NEED FOR A
   WW.
   
   ASCENT OFFERED BY A SUBTLE MID-LEVEL VORT MAX EMBEDDED WITHIN BROAD
   CYCLONIC FLOW OVER THE MID-ATLANTIC STATES /PER RECENT WATER VAPOR
   IMAGERY/ IS BEING AUGMENTED BY SFC CONVERGENCE ALONG A TROUGH LYING
   IN THE LEE OF THE APPALACHIANS PER 18Z SFC MESOANALYSIS. THIS
   ASCENT...FURTHER REINFORCED BY OROGRAPHIC FORCING AND JUXTAPOSED
   WITH MLCAPE VALUES OF 1000-2000 J/KG PER MODIFICATIONS TO THE 12Z
   BLACKSBURG VA RAOB TO ACCOUNT FOR CURRENT OBS...IS FOSTERING THE
   DEVELOPMENT OF ISOLATED TO SCATTERED CONVECTION NEAR AND JUST EAST
   OF THE BLUE RIDGE. CONVECTION COULD INCREASE IN NUMBER/INTENSITY
   WHILE BEING STEERED EWD OVER ADJACENT SECTIONS OF THE PIEDMONT
   REGION...WHERE DESTABILIZATION OWING TO AMPLE INSOLATION IS ONGOING.
   FURTHERMORE...A VERY MODEST ENHANCEMENT TO THE MID-LEVEL FLOW IN
   ASSOCIATION WITH THE VORT MAX IS GENERATING EFFECTIVE BULK SHEAR
   MAGNITUDES OF 20-30 KT...PRIMARILY NEAR AND ADJACENT TO THE SRN
   APPALACHIANS. THIS SHEAR COULD SUPPORT OCCASIONAL MULTICELL
   CONVECTION...WITH WEAKER VERTICAL SHEAR ELSEWHERE MORE SUPPORTIVE OF
   PULSE CONVECTION. GUSTY WINDS WILL BE THE MAIN CONCERN WITH THIS
   ACTIVITY...AND AN ISOLATED INSTANCE OR TWO OF DMGG WIND GUSTS CANNOT
   ENTIRELY BE RULED OUT. HOWEVER...THE LACK OF STRONGER FORCING /
   VERTICAL SHEAR SHOULD LARGELY PREVENT CONVECTION FROM ACHIEVING ANY
   SUBSTANTIAL ORGANIZATION AND MITIGATE THE SVR THREAT.
   
   ..COHEN.. 08/18/2011
   
   
   ATTN...WFO...AKQ...LWX...RAH...RNK...GSP...MRX...FFC...
   
   LAT...LON   36098315 36728195 37637997 38337858 37647827 36207964
               34668213 34608398 35188428 36098315