MESOSCALE DISCUSSION 1269
   NWS STORM PREDICTION CENTER NORMAN OK
   0750 PM CDT SUN JUN 21 2009
   
   AREAS AFFECTED...NRN WASATCH / SWRN WY
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 489...
   
   VALID 220050Z - 220145Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 489
   CONTINUES.
   
   REMAINING SEVERE POTENTIAL WILL LIKELY BE CONFINED TO ERN PORTIONS
   OF WW 489 FOR THE NEXT COUPLE OF HOURS.
   
   COMPOSITE SURFACE/RADAR ANALYSIS SHOWS A 1002 MB LOW INVOF SLC WITH
   AN EWD SWEEPING CONVECTIVE OUTFLOW BOUNDARY EXTENDING FROM ERN
   PORTIONS OF THE GREAT SALT LAKE SWWD INTO CNTRL TOOELE COUNTY.  THE
   AIRMASS TO THE W OF THE BOUNDARY AND AS WELL AS MUCH OF SERN ID HAS
   BEGUN TO STABILIZE DUE IN LARGE PART TO CONVECTIVE OVERTURNING. 
   FARTHER S IN SRN PARTS OF WW...BOUNDARY LAYER HAS BECOME MORE DEEPLY
   MIXED WITH TEMPS RISING INTO THE LOWER 80S WITH DEWPOINTS FALLING
   INTO THE MID 40S /PER RECENT PROVO OBSERVATION/.  THEREFORE THE
   LEAST DISTURBED THERMODYNAMIC ENVIRONMENT IS LIKELY LOCATED OVER THE
   NRN WASATCH EXTENDING NEWD INTO SWRN WY.  
   
   00Z SLC RAOB EXHIBITED VERY STEEP LAPSE RATES AMIDST A VEERING LOW
   LEVEL PROFILE WITH MORE THAN ADEQUATE DEEP LAYER SHEAR / 40 KTS 0-6
   KM SHEAR/ FOR STORM ORGANIZATION.  THIS WILL CONTINUE TO SUPPORT THE
   POTENTIAL FOR STORMS TO AQUIRE BRIEF ROTATION AT TIMES...WITH THE
   STRONGER STORMS BEING CAPABLE OF MAINLY ISOLD LARGE HAIL/DMGG WIND
   BEFORE STABILIZING PROCESSES /I.E. ADDITIONAL CONVECTIVE OVERTURNING
   AND DIURNAL COOLING/ COMMENCE AND BECOME MORE WIDESPREAD.
   
   ..SMITH.. 06/22/2009
   
   
   ATTN...WFO...RIW...SLC...PIH...
   
   LAT...LON   40961175 41321183 42661163 43341096 43291026 43050972
               42640948 40881016 40661080 40631128 40961175