MESOSCALE DISCUSSION 0628
   NWS STORM PREDICTION CENTER NORMAN OK
   0153 PM CDT TUE MAY 12 2015

   AREAS AFFECTED...PORTIONS OF SRN ID...FAR NERN NV...FAR NRN UT...FAR
   WRN WY

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 121853Z - 122100Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...THUNDERSTORMS HAVE DEVELOPED IN THE HIGH TERRAIN AND WILL
   EXPAND IN COVERAGE IN THE NEXT FEW HOURS. LOCALLY DMGG WIND GUSTS
   AND MARGINALLY SEVERE HAIL ARE POSSIBLE BUT A WATCH IS NOT
   ANTICIPATED AT THIS TIME.

   DISCUSSION...THUNDERSTORMS ARE DEVELOPING ON THE HEATED HIGH TERRAIN
   IN THE MCD AREA INVOF AN INVERTED TROUGH EMANATING FROM A SURFACE
   LOW PRESSURE AREA OVER CENTRAL NV. BOUNDARY-LAYER MOISTURE IS
   SOMEWHAT HIGHER THAN FORECAST BY THE 12Z NAM AND RECENT RAP
   RUNS...ESPECIALLY FROM THE SNAKE-RIVER VALLEY EWD INTO SERN
   ID...WHERE SURFACE DEWPOINTS HAVE HELD IN THE MID- TO UPPER 40S OVER
   MUCH OF THE AREA. MID-LEVEL LAPSE RATES OF 7.5 TO 8.0 C/KM AND VERY
   STEEP LOW-LEVEL LAPSE RATES IN THE MODESTLY MOIST BOUNDARY LAYER
   WILL SUPPORT SCATTERED THUNDERSTORMS CAPABLE OF LOCALLY-DMGG WIND
   GUSTS AND MARGINALLY SEVERE HAIL. WIND SHEAR IN THE CLOUD-BEARING
   LAYER OF 35-45 KT COULD SUPPORT LINEAR OR SMALL BOWING LINE SEGMENTS
   WHERE COLD POOLS CONSOLIDATE...WHICH WOULD LOCALLY ENHANCE THE
   SEVERE WIND THREAT. A WW IS NOT LIKELY AT THIS TIME BUT TRENDS WILL
   CONTINUE TO BE MONITORED.

   ..CONIGLIO/COHEN/CORFIDI.. 05/12/2015


   ATTN...WFO...RIW...TFX...SLC...PIH...MSO...BOI...LKN...PDT...

   LAT...LON   41631220 41561290 41621402 41781568 42281633 43181706
               43821762 44711834 45011806 45381762 45701729 45861610
               45841427 45271260 44391159 43611078 43341058 42801040
               42261086 41811163 41631220