MESOSCALE DISCUSSION 2140
   NWS STORM PREDICTION CENTER NORMAN OK
   1047 PM CDT MON SEP 05 2011
   
   AREAS AFFECTED...PORTIONS NWRN NC...SRN/CENTRAL VA.
   
   CONCERNING...TORNADO WATCH 844...
   
   VALID 060347Z - 060515Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 844 CONTINUES.
   
   PORTIONS WW HAVE BEEN CLEARED FROM S-N IN STEP WITH CONVECTIVE
   TRENDS.  REMAINDER WW MAY BE CLEARED BEFORE SCHEDULED 08Z
   EXPIRATION.
   
   WHILE SOME TORNADO POTENTIAL STILL EXISTS...IT IS BECOMING MORE
   MRGL/CONDITIONAL WITH TIME GIVEN TWO PRIMARY TRENDS...
   1. STABILIZING EFFECTS OF PERSISTENT PRECIP GENERALLY W OF
   CHO-ROA-MKJ LINE...WHICH HAS REINFORCED PRE-EXISTING BAROCLINIC
   ZONE...AND MAINTAINED OR EVEN INCREASED BOTH BOUNDARY-LAYER STATIC
   STABILITY AND MLCINH.
   2. GEN DECREASE IN OVERALL CONVECTIVE COVERAGE/DEPTH FARTHER UPSHEAR
   OVER CAROLINAS/GA...RELATED TO COMBINATION OF LACK OF LOW-LEVEL
   CONVERGENCE AND STABILIZING EFFECTS OF EARLIER PREFRONTAL MCS ACROSS
   SC.
   
   POCKETS OF MRGL INSTABILITY MAY STILL LINGER ACROSS THIS AREA...WITH
   MLCAPE 250-800 J/KG...AND PERSISTENCE OF ENHANCED LOW-LEVEL SRH
   CORRIDOR NEAR AND E OF BLUE RIDGE.  ANY PERSISTENT CELLS THAT FORM
   IN THIS ENVIRONMENT MAY ROTATE...HOWEVER LOW-LEVEL FORCING FOR
   ASCENT E OF FRONT REMAINS RATHER NEBULOUS.
   
   ..EDWARDS.. 09/06/2011
   
   
   ATTN...WFO...AKQ...LWX...RAH...RNK...
   
   LAT...LON   36668104 38037876 37747797 36497893 36268087 36668104