MESOSCALE DISCUSSION 0172
   NWS STORM PREDICTION CENTER NORMAN OK
   0352 PM CST TUE FEB 20 2007
   
   AREAS AFFECTED...SERN MO...NERN AR...WRN TN...EXTREME SRN IL/WRN KY
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 202152Z - 202315Z
   
   ...PORTIONS OF SERN MO...NERN AR...WRN TN AND EXTREME SRN IL/WRN KY
   ARE BEING MONITORED FOR A POSSIBLE WATCH...BY 00Z. 
   
   AT 21Z...A SURFACE LOW WAS LOCATED IN SOUTH CENTRAL MO...EAST OF
   SGF. A WEAK WARM FRONT EXTENDED EAST FROM THE SURFACE LOW...AND
   THOUGH CONVERGENCE ALONG THE FRONT WAS CURRENTLY WEAK...A WIND SHIFT
   /BOUNDARY MOVING SWD INTO SRN MO SHOULD STRENGTHEN THE CONVERGENCE. 
   TEMPERATURES HAVE WARMED INTO THE 70S AND LOWER TO MID 50S DEWPOINTS
   WERE RESULTING IN MLCAPES TO NEAR 1000 J/KG. VERY WARM TEMPERATURES
   AROUND 850 MB ARE CURRENTLY LIMITING SURFACE PARCELS FROM REACHING
   THE LFC...BUT THIS MAY CHANGE IN THE NEXT FEW HOURS AS LIFTING NEAR
   THE WARM FRONT WEAKENS THE CAP. IF SURFACE BASED STORMS DEVELOP...
   THE DEGREE OF INSTABILITY AND 60-70 KT DEEP LAYER SHEAR SHOULD BE
   SUFFICIENT FOR SEVERE STORMS...WITH COLD TEMPERATURES ALOFT
   SUGGESTING HAIL WOULD BE THE MAIN THREAT.
   
   ..IMY.. 02/20/2007
   
   
   ATTN...WFO...OHX...PAH...MEG...LSX...LZK...SGF...
   
   37089105 37528933 37318792 36918729 35268868 35269001
   35419115 35989143