MESOSCALE DISCUSSION 1408
   NWS STORM PREDICTION CENTER NORMAN OK
   0225 PM CDT SAT JUL 07 2007
   
   AREAS AFFECTED...SRN MT...NWRN/N-CNTRL WY...ERN ID
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 071925Z - 072100Z
   
   TSTMS WILL BECOME INCREASINGLY NUMEROUS AHEAD OF MID-LEVEL IMPULSE
   OVER SRN ID. MODEST DEEP-LAYER SHEAR SHOULD LIMIT THE OVERALL SEVERE
   THREAT...WITH A SEVERE TSTM WATCH ISSUANCE UNLIKELY ATTM.
   
   RECENT RADAR/LIGHTNING IMAGERY INDICATE TSTMS INCREASING IN AREAL
   EXTENT ACROSS THE HIGHER TERRAIN FROM THE SAWTOOTHS E/SEWD TO THE
   TETONS/WIND RIVER MTNS. THIS GROWTH IS LIKELY IN RESPONSE TO AN
   APPROACHING MID-LEVEL IMPULSE /EVIDENT IN WATER VAPOR IMAGERY IN 
   S-CNTRL WY/. ATTENDANT MODEST SPEED MAX OF 25 TO 30 KTS AT 500 MB
   /PER 12Z ELKO NV RAOB/...SHOULD BE SUFFICIENT FOR RELATIVELY BRIEF
   UPDRAFT ORGANIZATION. THIS MAY RESULT IN MARGINALLY SEVERE HAIL
   AMONGST STRONGER CORES. PERHAPS THE MORE SUBSTANTIAL THREAT WILL BE
   FROM GUSTY OUTFLOW WINDS INVOF BASIN/VALLEYS...ESPECIALLY FROM RIW
   TO BIL. WITHIN THIS CORRIDOR...TEMPERATURE/DEW POINT SPREADS HAVE
   ALREADY EXCEEDED 50 DEGREES. STEEP LOW-LEVEL LAPSE RATES/HIGH-BASED
   NATURE OF THE CONVECTION SHOULD SUPPORT ISOLATED STRONG TO SEVERE
   WIND GUSTS THROUGH THE AFTERNOON.
   
   ..GRAMS.. 07/07/2007
   
   
   ATTN...WFO...BYZ...RIW...TFX...PIH...MSO...BOI...
   
   46811032 46500817 45920689 45100629 43880649 43160786
   42820948 43111120 43511276 43781412 44541470 45231478
   46261337