MESOSCALE DISCUSSION 1989
   NWS STORM PREDICTION CENTER NORMAN OK
   0933 PM CDT TUE SEP 25 2012
   
   AREAS AFFECTED...WRN OK...NWRN TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 650...
   
   VALID 260233Z - 260400Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 650
   CONTINUES.
   
   SUMMARY...LOCALLY DAMAGING WINDS AND PERHAPS SOME LARGE HAIL WILL
   ACCOMPANY REMNANT CONVECTION AS IT SPREADS EWD ACROSS THE SWRN
   QUADRANT OF OK AND ADJACENT REGIONS OF NWRN TX.
   
   DISCUSSION...DIURNALLY DRIVEN CONVECTION THAT DEVELOPED OVER THE SRN
   HIGH PLAINS OF NWRN TX/WRN OK HAS PROGRESSED DOWNSTREAM INTO
   PORTIONS OF CNTRL OK AT ROUGHLY 25KT.  THIS ACTIVITY APPEARS TO BE
   PARTLY SUPPORTED ALOFT BY A WEAK SHORT-WAVE TROUGH WITH MODEST WLY
   COMPONENT AT MID LEVELS.  ONGOING CONVECTION HAS PRODUCED PERIODIC
   STRONG DOWNDRAFTS DUE IN PART TO STEEP LAPSE RATE ENVIRONMENT
   COUPLED WITH RELATIVELY DRY SUB-CLOUD LAYER AND MARGINAL SFC DEW
   POINTS.  IT APPEARS DIURNAL COOLING WILL CONTRIBUTE TO A STABILIZING
   BOUNDARY LAYER OVER THE NEXT SEVERAL HOURS WHICH SHOULD LESSON THE
   SEVERE WIND THREAT WITH TIME.
   
   ..DARROW.. 09/26/2012
   
   
   ATTN...WFO...FWD...OUN...LUB...
   
   LAT...LON   33390022 36979916 36959699 33399812 33390022