MESOSCALE DISCUSSION 0758
   NWS STORM PREDICTION CENTER NORMAN OK
   0455 PM CDT TUE MAY 21 2013
   
   AREAS AFFECTED...PARTS OF E-CNTRL AND SERN TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 212155Z - 212330Z
   
   PROBABILITY OF WATCH ISSUANCE...60 PERCENT
   
   SUMMARY...A STRONG TO SEVERE STORM THREAT WILL PROBABLY MOVE INTO
   PORTIONS OF E-CNTRL AND SERN TX THIS EVENING/TONIGHT.  ALTHOUGH
   ISOLD LARGE HAIL/DMGG WINDS WILL BE THE PRIMARY THREATS...A TORNADO
   IS ALSO POSSIBLE.
   
   DISCUSSION...RADAR MOSAIC SHOWS AN EXTENSIVE SQUALL LINE FROM WRN AR
   SWWD INTO N-CNTRL TX WITH SOME CELLULAR STORMS /INCLUDING THE BELL
   COUNTY SUPERCELL/ ON THE SRN FRINGE OF THE LINE OF STORMS. 
   SUBJECTIVE SURFACE MESOANALYSIS SHOWS THE N-CNTRL TX PORTION OF THE
   LINE JUXTAPOSED WITH THE COLD FRONT AND THEN EXTENDING SWWD OVER THE
   TX HILL COUNTRY.  FARTHER E...A PRE-FRONTAL CONFLUENCE ZONE HAS
   SERVED TO PREFERENTIALLY FAVOR CELLULAR DEVELOPMENT ON THE SRN
   PORTION OF THE LINE WITH THE FRONTAL LIFT DISPLACED 1-2 COUNTIES
   WEST.  SURFACE TEMPS HAVE WARMED TO NEAR 90 DEG F WITH DEWPOINTS
   AROUND 70 DEG F...CONTRIBUTING TO A VERY UNSTABLE AIRMASS /2500-3000
   MLCAPE PER OBJECTIVE ANALYSIS/.  THE KGRK VWP SHOWS 0-6 KM SHEAR /40
   KT/ MORE THAN SUFFICIENT FOR ORGANIZED LINE SEGMENTS AND SUPERCELLS.
   ALTHOUGH LOW LEVEL SHEAR IS MODEST /100 M2/S2 0-1 KM SRH/...A
   TORNADO IS POSSIBLE...ESPECIALLY IF A MORE FAVORABLE CONVECTIVE MODE
   CAN BE MAINTAINED AS STORMS MOVE INTO THE DISCUSSION AREA.
   
   ..SMITH/CORFIDI.. 05/21/2013
   
   
   ATTN...WFO...LCH...SHV...HGX...FWD...EWX...
   
   LAT...LON   30589692 31549540 30969430 30429698 30589692