MESOSCALE DISCUSSION 1911
   NWS STORM PREDICTION CENTER NORMAN OK
   0335 PM CDT TUE AUG 18 2009
   
   AREAS AFFECTED...SERN WY/SWRN AND S CENTRAL SD/PARTS OF NWRN NEB AND
   THE NEB PNHDL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 182035Z - 182230Z
   
   INCREASE IN CONVECTION FORECAST OVER THE NEXT COUPLE OF HOURS COULD
   WARRANT WW ISSUANCE.
   
   TCU/CB DEVELOPMENT CONTINUES TO EXPAND ACROSS THE DISCUSSION AREA
   PER LATEST VISIBLE SATELLITE IMAGERY...IN CONJUNCTION WITH DAYTIME
   HEATING WHICH HAS CONTRIBUTED TO THE DEVELOPMENT OF 1000 TO 2000
   J/KG MIXED LAYER CAPE.  THE OBSERVED INCREASE IN CONVECTION APPEARS
   TO BE ASSOCIATED WITH A VERY WEAK/SUBTLE CIRCULATION
   CENTER...EVIDENT IN LATEST WV LOOP MOVING EWD ACROSS THE WRN
   DAKOTAS.
   
   WHILE ADDITIONAL DESTABILIZATION SHOULD REMAIN LIMITED DUE TO MODEST
   BOUNDARY-LAYER MOISTURE...SHEAR PROFILES -- PER LATEST VWP/PROFILER
   OBS -- ARE SUPPORTIVE OF MULTICELL/WEAK SUPERCELL ORGANIZATION. 
   RESULTING SEVERE POTENTIAL IN CONJUNCTION WITH THE ANTICIPATED
   INCREASE IN CONVECTIVE COVERAGE COULD EVENTUALLY WARRANT WW
   ISSUANCE.
   
   ..GOSS.. 08/18/2009
   
   
   ATTN...WFO...FSD...ABR...LBF...UNR...BOU...CYS...
   
   LAT...LON   40980416 41060451 41510449 43240344 44430335 44840162
               43829925 42859892 41070159 40980416