MESOSCALE DISCUSSION 0855
   NWS STORM PREDICTION CENTER NORMAN OK
   0148 PM CDT MON JUN 01 2015

   AREAS AFFECTED...SERN IDAHO...NWRN WY AND SWRN MT

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 011848Z - 012045Z

   PROBABILITY OF WATCH ISSUANCE...60 PERCENT

   SUMMARY...THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND
   INTENSITY FROM SERN IDAHO INTO NWRN WY AND SWRN MT AFTER 19-20Z. THE
   PRIMARY THREATS WILL BE LARGE HAIL AND DAMAGING WIND GUSTS. TRENDS
   ARE BEING MONITORED FOR A WW.

   DISCUSSION...MOSTLY SUNNY CONDITIONS ARE DESTABILIZING THE BOUNDARY
   LAYER FROM SERN ID INTO NWRN WY AND SWRN MT THIS AFTERNOON. SFC
   DEWPOINTS AROUND 50F ALONG WITH STEEP MID-LEVEL LAPSE RATES ARE
   SUPPORTING 1000-1500 J/KG MLCAPE. OBSERVED SOUNDINGS AND RUC PFCS
   INDICATE CONVECTIVE INHIBITION WILL WEAKEN SUFFICIENTLY TO SUPPORT
   MORE ROBUST STORM DEVELOPMENT AS SFC TEMPERATURES APPROACH 80F. SOME
   INCREASE IN THUNDERSTORM INTENSITY HAS BEEN RECENTLY OBSERVED NEAR
   THE ID/NEV BORDER. ADDITIONAL STORMS SHOULD INCREASE ALONG AND AHEAD
   OF PRE-EXISTING CONVECTIVE OUTFLOW BOUNDARY CURRENTLY EXTENDING FROM
   SRN IDAHO INTO SWRN MT. WV IMAGERY SHOWS WELL DEFINED VORTICITY
   MAXIMUM APPROACHING SWRN ID. FORCING FOR ASCENT ACCOMPANYING THIS
   FEATURE SHOULD FURTHER SUPPORT AN INCREASE IN THUNDERSTORMS. A 40 KT
   MID-LEVEL JET MOVING THROUGH BASE OF VORT MAX HAS OVERSPREAD THE
   UNSTABLE WARM SECTOR...CONTRIBUTING TO 30-40 KT EFFECTIVE BULK SHEAR
   WHICH WILL PROMOTE UPDRAFT ROTATION. BOTH BOWING SEGMENTS AND SOME
   SUPERCELL STRUCTURES ARE POSSIBLE AS STORMS MATURE LATER THIS
   AFTERNOON AND EVENING.

   ..DIAL/MEAD.. 06/01/2015


   ATTN...WFO...BYZ...RIW...TFX...SLC...PIH...MSO...BOI...

   LAT...LON   41961372 42681405 43531328 44401286 45231290 45871177
               45880995 44631054 42321110 41961372