MESOSCALE DISCUSSION 0639
   NWS STORM PREDICTION CENTER NORMAN OK
   1035 PM CDT MON MAY 13 2013
   
   AREAS AFFECTED...CENTRAL MT
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 159...
   
   VALID 140335Z - 140430Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 159
   CONTINUES.
   
   SUMMARY...OVERALL SEVERE WEATHER THREAT WILL CONTINUE TO
   DIMINISH...ALLOWING WW 159 TO EXPIRE AT 04Z.
   
   DISCUSSION...FORCING FOR ASCENT/HEIGHT FALLS SPREADING EWD FROM
   CENTRAL MT INTO THE NRN PLAINS TONIGHT WILL SUPPORT A CONTINUATION
   IN CONVECTION WITH EWD EXTENT.  IN ADDITION...AN INCREASE IN LOW
   LEVEL WAA AND THE PRESENCE OF STEEP MIDLEVEL LAPSE RATES SUGGEST
   TSTMS WILL REMAIN POSSIBLE...WITH THIS ACTIVITY BEING MAINLY
   ELEVATED GIVEN THE INCREASE IN SURFACE BASED INHIBITION. THUS...THE
   DECREASE IN INSTABILITY IS EXPECTED TO LIMIT THE OVERALL SEVERE
   WEATHER THREAT AND PRECLUDES THE NEED FOR A NEW WATCH ISSUANCE.
   
   ..PETERS.. 05/14/2013
   
   
   ATTN...WFO...BYZ...GGW...TFX...MSO...
   
   LAT...LON   46391222 46941288 48231327 48601213 48361119 48470677
               47080730 46391222