MESOSCALE DISCUSSION 0422
   NWS STORM PREDICTION CENTER NORMAN OK
   1256 PM CDT TUE APR 12 2011
   
   AREAS AFFECTED...SERN VA...SRN EXTENT OF DELMARVA PENINSULA...AND
   NERN NC
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 121756Z - 121900Z
   
   ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON
   ACROSS SERN VA...SRN EXTENT OF THE DELMARVA PENINSULA AND ACROSS
   NERN NC.  GIVEN SPATIOTEMPORAL LIMITATIONS...A WW APPEARS TO BE NOT
   WARRANTED ACROSS THIS AREA.
   
   EARLY AFTERNOON SURFACE ANALYSIS SHOWED AN AREA OF LOW PRESSURE
   LOCATED ALONG THE WEST CENTRAL VA BORDER WITH WV...AND AN OCCLUDED
   BOUNDARY EXTENDING EWD TO JUST N OF RIC...WITH THIS BOUNDARY THEN
   EXTENDING EWD AS A WARM FRONT THROUGH SRN DELMARVA JUST S OF DE.  A
   DOUBLE COLD FRONT STRUCTURE WAS ANALYZED...WITH THE LEADING FRONT
   EXTENDING SWD FROM THE OCCLUDED/WARM FRONT JUNCTURE THROUGH ERN NC
   AND E OF SC/GA...THEN SWWD THROUGH NRN FL.  THE SECOND COLD FRONT
   EXTENDED SWD FROM THE WRN VA LOW THROUGH THE CENTRAL CAROLINAS TO
   NWRN FL.
   
   REGIONAL RADAR IMAGERY SHOWED A FEW TSTMS HAVE DEVELOPED IN THE NRN
   EXTENT OF THE WARM SECTOR OVER SERN VA...WITH ADDITIONAL DEVELOPMENT
   POSSIBLE AS THE LEAD COLD FRONT ADVANCES ENEWD THROUGH THE
   DISCUSSION AREA.  STRONG SURFACE HEATING HAS ELIMINATED THE SURFACE
   BASED INHIBITION AND IS SUPPORTING MODERATE INSTABILITY /MLCAPE
   1000-1500 J PER KG/.  THIS COMBINED WITH EFFECTIVE BULK SHEAR OF
   50-70 KT/ WILL SUPPORT ORGANIZED STORMS WITH HAIL AND STRONG WIND
   GUSTS THE PRIMARY THREATS...GIVEN THE AVAILABLE INSTABILITY AND
   STEEP LAPSE RATES.  THUS FAR...THE STRONGEST STORMS HAVE OCCURRED
   WITH ACTIVITY AS IT APPROACHED THE WARM FRONT...WHERE LOW LEVEL
   WINDS ARE LOCALLY BACKED...ENHANCING SHEAR VALUES.  FAST STORM
   MOTIONS TOWARD THE NNE AT 45-50 KT WILL RESULT IN STORMS QUICKLY
   MOVING N OF THE WARM FRONT AND WEAKENING IN A MORE STABLE AIR MASS. 
   GIVEN THIS FACTOR AND A RELATIVELY SMALL AREAL COVERAGE FOR THE
   OVERALL SEVERE WEATHER THREAT THIS AFTERNOON...A WW APPEARS TO NOT
   BE WARRANTED.
   
   ..PETERS.. 04/12/2011
   
   
   ATTN...WFO...AKQ...MHX...LWX...
   
   LAT...LON   36247561 35927689 36587691 37897740 38307597 38257500
               37167562 36247561