MESOSCALE DISCUSSION 1280
   NWS STORM PREDICTION CENTER NORMAN OK
   0107 AM CDT TUE JUN 23 2009
   
   AREAS AFFECTED...WESTERN NEB/SOUTHWEST SD
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 230607Z - 230700Z
   
   A DAMAGING WIND/HAIL THREAT MAY CONTINUE OVERNIGHT
   EAST-NORTHEASTWARD ACROSS PORTIONS OF WESTERN NEB INTO SOUTHWEST SD.
   CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WATCH.
   
   ONGOING STRONG/SEVERE CONVECTIVE CLUSTER NEAR THE CO/WY/NEB BORDER
   VICINITY CONTINUES TO STEADILY EXPAND/DEVELOP EAST-NORTHEASTWARD
   EARLY IN THE OVERNIGHT. WHILE A SURFACE COLD POOL CONTINUES TO
   EXPAND/ORGANIZE...INCREASING EASTERLY FLOW HAS BEEN NOTED IN THE
   LOWEST 1 KM OF THE NORTH PLATTE WSR-88D VWP AHEAD OF THIS EVOLVING
   MCS. THESE TRENDS...ALONG WITH VEERING WIND PROFILES/STEEP MID LEVEL
   LAPSE RATES PER 00Z OBSERVED NORTH PLATTE/RAPID CITY/BOULDER
   RAOBS...MAY CONTRIBUTE TO A SUSTAINED/AT LEAST ISOLATED DAMAGING
   WIND/HAIL RISK OVERNIGHT ACROSS WESTERN NEB INTO SOUTHWEST SD.
   
   ..GUYER.. 06/23/2009
   
   
   ATTN...WFO...LBF...UNR...BOU...CYS...
   
   LAT...LON   40830363 41300419 42760383 43670132 42609922 40950081
               40830363