MESOSCALE DISCUSSION 1625
   NWS STORM PREDICTION CENTER NORMAN OK
   0107 PM CDT MON JUL 20 2009
   
   AREAS AFFECTED...SERN ND / NERN SD / NWRN AND W-CNTRL MN
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 201807Z - 201930Z
   
   THE THREAT FOR ISOLATED SEVERE STORMS CAPABLE OF DAMAGING WIND GUSTS
   AND HAIL SHOULD INCREASE THROUGH THE AFTERNOON.  CONVECTIVE TRENDS
   ARE BEING MONITORED FOR A POSSIBLE WW.
   
   LATEST MESOANALYSIS INDICATED COLD FRONT EXTENDING FROM E HCO-W OF
   FAR-ABR-E OF PIR.  WHILE MAJORITY OF TSTM ACTIVITY OVER WRN/CNTRL
   PARTS OF THE DAKOTAS HAVE LARGELY BEEN ELEVATED WITHIN POST-FRONTAL
   AIR MASS...RECENT RADAR DATA AND VISIBLE SATELLITE IMAGERY INDICATE
   INCREASING STORM DEVELOPMENT NEAR FRONT FROM ABR NEWD TO E OF TVF. 
   PRE-FRONTAL BOUNDARY LAYER HAS REMAINED RATHER COOL WITH
   TEMPERATURES LINGERING IN THE 70S.  HOWEVER...BASED ON 12Z BIS/RAP
   SOUNDINGS...MIDLEVEL LAPSE RATES ARE LIKELY STEEPENING IN ADVANCE OF
   SHORT WAVE TROUGH TRANSLATING EWD THROUGH THE NRN HIGH PLAINS.
   
   INCREASED FORCING FOR ASCENT ASSOCIATED WITH SHORT WAVE TROUGH
   COUPLED WITH GRADUAL AIR MASS DESTABILIZATION SHOULD SUPPORT A
   CONTINUED INCREASE IN STORM COVERAGE AND INTENSITY ALONG COLD FRONT
   THIS AFTERNOON.  VERTICAL SHEAR WILL REMAIN SOMEWHAT MARGINAL /AOB
   30-35 KT/...BUT THE STRONGER STORMS WILL BE CAPABLE OF SOME HAIL AND
   GUSTY WINDS.
   
   ..MEAD.. 07/20/2009
   
   
   ATTN...WFO...MPX...FGF...FSD...ABR...BIS...
   
   LAT...LON   44649890 45359878 47039716 47939645 47829560 47189516
               45569585 44469667 44189805 44649890