MESOSCALE DISCUSSION 0843
   NWS STORM PREDICTION CENTER NORMAN OK
   0347 PM CDT FRI MAY 09 2008
   
   AREAS AFFECTED...ERN WY...SWRN SD...NEB PANHANDLE...NERN CO AND FAR
   NWRN
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 287...288...
   
   VALID 092047Z - 092245Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   287...288...CONTINUES.
   
   SEVERAL STG/SVR TSTMS WILL CONTINUE TO MOVE ACROSS WW/S 287/288 OVER
   THE NEXT FEW HOURS. THREAT FOR SVR HAIL/WIND WILL REMAIN WITH THE
   MOST ORGANIZED TSTMS. ACTIVITY MAY BEGIN TO SPREAD EAST OF PORTIONS
   OF WW 287 BEFORE 00Z AND THIS AREA WILL BE MONITORED FOR A POSSIBLE
   LOCAL WFO WATCH EXTENSION.
   
   STRENGTHENING MID LEVEL FLOW PER RECENT MEDICINE BOW PROFILER DATA
   /50 KTS AT 3 KM/ WAS MOVING ACROSS ERN WY...AND WILL CONTINUE TO
   DEVELOP EWD INTO SWRN SD/NEB PANHANDLE OVER THE NEXT SEVERAL HOURS.
   THE INCREASING MID LEVEL WINDS SHOULD SUPPORT AN INCREASE IN THE
   FORWARD STORM MOTION OF ONGOING CONVECTION OVER THE REGION. SFC
   ANALYSIS SHOWS A NARROW INSTABILITY AXIS WAS GRADUALLY EXPANDING EWD
   ACROSS SWRN SD/WRN NEB. THUS TSTMS CURRENTLY OVER THE NEB PANHANDLE
   ARE EXPECTED TO CONTINUE TO SUPPORT A SVR THREAT AFTER THEY MOVE OUT
   OF WW 287 BY 00Z. GIVEN THE LIMITED AREAL EXTENT OF ADDITIONAL SVR
   THREAT EAST OF WW 287 THROUGH SUNSET...A LOCAL EXTENSION OF WW 287
   MAY BECOME NECESSARY AFTER BEFORE 00Z. ADDITIONAL STRONG TSTMS OVER
   CENTRAL WY ARE EXPECTED TO INTENSIFY AS THEY ENCOUNTER GREATER
   INSTABILITY OVER ERN WY.
   
   FURTHER SOUTH OVER WW 288...TSTM INITIATION HAS BEEN SLOW TO OCCUR.
   HOWEVER...STRENGTHENING VERTICAL MOTION AHEAD OF SHORTWAVE TROUGH
   MOVING THROUGH WRN CO COMBINED WITH MODERATE SFC CONVERGENCE ALONG A
   DRYLINE SHOULD SUPPORT ISOLATED SVR TSTM DEVELOPMENT BEFORE 00Z.
   
   ..CROSBIE.. 05/09/2008
   
   
   ATTN...WFO...LBF...DDC...UNR...GLD...BOU...CYS...BYZ...RIW...
   
   39050315 39550316 39560381 39960375 40000344 40520348
   40970365 40990533 42350521 42490604 45000602 45030513
   44170500 44170402 43940396 43900277 42990296 42990212
   41030205 41020127 40280127 40300076 39210065 39080018
   38650019 38660187 39040198