MESOSCALE DISCUSSION 1277
   NWS STORM PREDICTION CENTER NORMAN OK
   0628 PM CDT MON JUN 22 2009
   
   AREAS AFFECTED...WRN AND CNTRL ND
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 492...
   
   VALID 222328Z - 230100Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 492
   CONTINUES.
   
   THREAT FOR ISOLATED DAMAGING WIND AND HAIL WILL PERSIST ACROSS CNTRL
   ND NEXT 2-3 HOURS. SOME STORMS WILL APPROACH THE ERN LIMITS OF WW
   492 NEAR 01Z. CURRENT THINKING IS THAT STORMS MIGHT BEGIN TO
   STRUGGLE AFTER ANOTHER COUPLE HOURS. HOWEVER...DEPENDING ON
   CONVECTIVE TRENDS...WW MIGHT NEED TO BE LOCALLY EXTENDED FARTHER
   EAST INTO BIS CWA.
   
   EARLY THIS EVENING WIDELY SCATTERED STORMS CONTINUE ALONG AND EAST
   OF A COUPLE CONVERGENCE BOUNDARIES ACROSS WRN AND CNTRL ND. THE
   ATMOSPHERE DOWNSTREAM REMAINS MODERATELY UNSTABLE WITH 1500 J/KG
   MLCAPE. WEAK LOW LEVEL FORCING AND WLY BULK SHEAR OF 35-50 KT
   SUGGEST DISCRETE SUPERCELLS WILL REMAIN THE DOMINANT MODE. RUC
   ANALYSIS AND WV IMAGERY INDICATE WEAK SHORTWAVE RIDGING IMPLYING
   NEUTRAL TO WEAK LARGE SCALE SUBSIDENCE HAS OVERSPREAD THIS REGION IN
   WAKE OF A SHORTWAVE TROUGH LIFTING NWD INTO MANITOBA. THIS IN
   CONJUNCTION WITH ONSET OF NOCTURNAL COOLING AND PRESENCE OF ONLY
   MODEST LOW LEVEL FORCING LOWERS CONFIDENCE THAT STORMS WILL BE ABLE
   TO PERSIST OR MAINTAIN THEIR INTENSITY BEYOND ABOUT 02Z.
   
   ..DIAL.. 06/22/2009
   
   
   ATTN...WFO...FGF...ABR...BIS...
   
   LAT...LON   48880047 48049966 46239958 45920113 46190264 47290285
               48720215 48880047