MESOSCALE DISCUSSION 0575
   NWS STORM PREDICTION CENTER NORMAN OK
   0434 PM CDT MON APR 25 2011
   
   AREAS AFFECTED...PORTIONS NRN MS...ERN AR...WRN TN...SERN MO...SRN
   IL...EXTREME SWRN INDIANA...EXTREME WRN KY.
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 252134Z - 252230Z
   
   ANOTHER WW IS LIKELY ACROSS MS VALLEY REGION E AND NE OF WW 205.
   
   SVR TSTMS OVER NERN PORTIONS AR IN WW 205 MAY BE MAINTAINED AS THEY
   MOVE NEWD INTO DESTABILIZING AIR MASS OVER THIS REGION.  MAIN
   UNCERTAINTY INVOLVES NRN EXTENT OF FAVORABLE/SFC-BASED EFFECTIVE
   INFLOW...GIVEN ROBUST STRENGTH OF COLD POOL OVER MO OZARKS AND
   LIMITED TIME FOR DESTABILIZATION TO ITS E.  SFC MESOANALYSIS SHOWED
   SRN EDGE OF THAT COLD POOL FROM NEAR FLP NEWD ACROSS CARTER COUNTY
   MO THEN NWD TOWARD SWRN FRINGES STL AREA...E OF WHICH 3-4 MB/2-HOUR
   FALLS ARE FOCUSED ACROSS SERN MO/NERN AR REGION.  THIS TENDENCY IS
   CONSISTENT WITH SFC LOW SHIFT/DEVELOPMENT NEWD INTO REGION...WHILE
   RELATED ISALLOBARIC FORCING WILL MAINTAIN BACKED NEAR-SFC WINDS AND
   ENLARGED LOW-LEVEL HODOGRAPHS FAVORABLE FOR SUPERCELLS/TORNADO
   POTENTIAL.  DEEP-LAYER SHEAR WILL REMAIN SUITABLE ALSO...WITH
   EFFECTIVE SHEAR MAGNITUDES AROUND 45-55 KT.  OUTFLOW BOUNDARY...N OF
   WHICH HODOGRAPHS ARE FURTHER ENLARGED...WAS ANALYZED FROM WRN KY MCS
   SWWD ACROSS MEM AREA THEN NWWD OVER NERN AR.  HOWEVER...SFC DIABATIC
   HEATING IS DESTABILIZING AIR MASS TO ITS N SUCH THAT 500-1500 MLCAPE
   MAY DEVELOP ACROSS SERN MO INTO SRN IL AND WRN KY BEFORE SUNSET. 
   WAA WILL MAINTAIN FAVORABLE BUOYANCY IN PRE-STORM ENVIRONMENT.
   
   ..EDWARDS.. 04/25/2011
   
   
   ATTN...WFO...OHX...PAH...MEG...JAN...LSX...LZK...
   
   LAT...LON   35319163 37059086 38158966 38228882 38158778 37468767
               35638842 34088901 33879075 34299180 35319163