MESOSCALE DISCUSSION 1663
   NWS STORM PREDICTION CENTER NORMAN OK
   0349 PM CDT TUE JUL 19 2011
   
   AREAS AFFECTED...CNTRL THROUGH N-CNTRL MT
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 192049Z - 192215Z
   
   ISOLATED DOWNBURST WINDS WILL BE POSSIBLE INTO THE EARLY TO MIDDLE
   EVENING AS STORMS INCREASE ACROSS CNTRL MT. WW ISSUANCE IS POSSIBLE
   BUT NOT LIKELY GIVEN THAT COVERAGE OF SEVERE EVENTS IS EXPECTED TO
   REMAIN SOMEWHAT ISOLATED.
   
   OROGRAPHIC FORCING EMBEDDED WITHIN ZONE OF DEEPER ASCENT ASSOCIATED
   WITH PROGRESSIVE SHORTWAVE TROUGH MOVING INTO THE NRN ROCKIES WILL
   LIKELY SUPPORT ADDITIONAL STORMS DEVELOPING FROM W-CNTRL THROUGH
   CNTRL MT INTO THE EVENING. DEEPLY MIXED BOUNDARY LAYERS WITH STEEP
   LAPSE RATES...TEMPERATURE-DEWPOINT SPREADS AROUND 50F AND MLCAPE AOB
   1000 J/KG IS SUPPORTING HIGH BASED STORMS THAT WILL LIKELY DEVELOP
   UPDRAFT ROTATION GIVEN 40-50 KT EFFECTIVE SHEAR. THIS ENVIRONMENT
   WILL SUPPORT POTENTIAL FOR DOWNBURSTS AND AT LEAST MARGINALLY SEVERE
   HAIL. OVERALL THREAT APPEARS SOMEWHAT LIMITED BY A RELATIVELY
   SHALLOW CAPE LAYER WITH MODEST INSTABILITY...AND COVERAGE OF SEVERE
   EVENTS IS EXPECTED TO REMAIN ISOLATED.
   
   ..DIAL.. 07/19/2011
   
   
   ATTN...WFO...BYZ...GGW...TFX...
   
   LAT...LON   48920876 48620730 47110782 46391043 47311222 48621156
               48920876