MESOSCALE DISCUSSION 1278
   NWS STORM PREDICTION CENTER NORMAN OK
   0338 PM CDT SAT JUN 18 2011
   
   AREAS AFFECTED...SWRN/S CNTRL OK...CNTRL AND WRN TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 182038Z - 182130Z
   
   CORRECTED FOR WATCH LIKELIHOOD
   
   ISOLATED SUPERCELLS MAY DEVELOP LATE THIS AFTERNOON/EVENING ALONG A
   DRYLINE EXTENDING THROUGH S CNTRL/SWRN OK SWWD TO THE BIG BEND. ANY
   STORMS THAT CAN DEVELOP WILL BE CAPABLE OF HAIL AND DMGG WINDS.
   SHOULD COVERAGE APPEAR GREATER THAN ISOLATED...A WW MAY BE POSSIBLE
   AND AN UPGRADE TO SLIGHT WILL BE CONSIDERED.
   
   VISIBLE IMAGERY SHOWS AN INCREASING CU FIELD...PARTIALLY IN RESPONSE
   TO FAVORABLE SURFACE CONVERGENCE ALONG THE DRYLINE. 18Z LAMONT OK
   SOUNDING SHOWS A VERY STRONG CAP /16 C AT 700 MB/...WHILE AREA 12Z
   SOUNDINGS AND THE 18Z LMN SOUNDING SUGGEST CONVECTIVE INHIBITION MAY
   BE OVERCOME GIVEN A SURFACE TEMPERATURE OF NEAR 103 TO 107 F.
   SURFACE OBSERVATIONS ARE SHOWING VERY HOT TEMPERATURES IN
   GENERAL...WITH 111 F AT WICHITA FALLS...AND 106 F AHEAD OF THE
   DRYLINE IN MINERAL WELLS. AS SUCH...CAPPING MAY BE WEAK AT THE
   MOMENT. MODEL FORECASTS SUGGEST A JET STREAK FROM ERN NM INTO WRN TX
   MAY BE IMPINGING ON THE DRYLINE...AND APPEARS TO BE SUPPORTED BY 6
   KM PROFILER DATA WHICH SHOWS 40-45 KTS IN THIS AREA.
   MEANWHILE...WEAK HEIGHT FALLS WILL CONTINUE TO DEVELOP EWD IN
   ADVANCE OF A LARGER SCALE UPPER TROUGH. AFOREMENTIONED WEAK UPPER
   FORCING MAY BE SUFFICIENT FOR ISOLATED DEVELOPMENT. IF A STORM CAN
   FORM...GIVEN AN EXTREMELY SUPPORTIVE THERMODYNAMIC ENVIRONMENT AND
   MODEST FLOW...RAPID DEVELOPMENT OF SUPERCELLS CAPABLE OF DMGG WINDS
   AND HAIL WILL BE POSSIBLE.
   
   ..HURLBUT.. 06/18/2011
   
   
   ATTN...WFO...FWD...OUN...SJT...MAF...
   
   LAT...LON   31580037 31660108 32280093 32909950 33909836 34449798
               34599767 34299726 32969840 32349908 31580037