MESOSCALE DISCUSSION 0147
   NWS STORM PREDICTION CENTER NORMAN OK
   1244 PM CST SUN FEB 27 2011
   
   AREAS AFFECTED...NERN AR / NWRN MS / WRN TN / MO BOOTHEEL / FAR WRN
   KY
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 271844Z - 272015Z
   
   NEXT 1-2 HRS WILL BE MONITORING FOR STORM DEVELOPMENT/SUSTENANCE
   OVER NERN AR AND WRN TN AND A CONDITIONAL RISK FOR ISOLD TORNADOES. 
   IF/ONCE UPDRAFTS BECOME ROOTED IN THE BOUNDARY LAYER...AN ENSUING
   ISOLD TORNADO THREAT WILL LIKELY EXIST.
   
   RECENT VISIBLE SATELLITE IMAGERY SHOWS THINNING HIGHER LEVEL CLOUD
   COVER ACROSS ERN AR EWD INTO NWRN MS AND WRN TN LEADING TO POCKETS
   OF INCREASED HEATING.  IN THE LOW LEVELS...SURFACE TEMPS GENERALLY
   NEAR AND S OF I-40 ARE IN THE LOWER 70S WITH DEWPOINTS RISING INTO
   THE LOWER 60S WITHIN A MOIST PLUME EXTENDING UP THE MS RIVER VALLEY.
   THIS IN TURN IS RESULTING IN 500-1000 J/KG MLCAPE AND A WEAKENED
   CAP.  REPEATED CONVECTIVE ATTEMPTS INVOF THE MS/AR/TN BORDER MAY
   EVENTUALLY BREACH THE REMAINING CAP AND LEADING TO ISOLD-SCTD STORMS
   BY MID AFTERNOON.  THE LAST FEW RUNS OF THE HRRR HAVE SUGGESTED
   SHALLOW CONVECTION NEAR MIDDAY WILL GRADUALLY DEEPEN BY 20Z. 
   IF/ONCE THIS OCCURS...SIZABLE CLOCKWISE CURVED LOW LEVEL HODOGRAPHS
   PER NQA VAD DATA /30 KTS 0-1 KM SHEAR/ WITHIN AN INCREASINGLY
   MOIST/DESTABILIZING BOUNDARY LAYER WILL SUPPORT UPDRAFT ROTATION AND
   AN ATTENDANT TORNADO THREAT.
   
   ..SMITH.. 02/27/2011
   
   
   ATTN...WFO...OHX...PAH...MEG...LZK...
   
   LAT...LON   34709075 35179109 36728938 36678844 36298803 35578804
               34578999 34709075