MESOSCALE DISCUSSION 1028
   NWS STORM PREDICTION CENTER NORMAN OK
   0829 PM CDT MON JUN 15 2015

   AREAS AFFECTED...WY...SE ID...NRN UT

   CONCERNING...SEVERE THUNDERSTORM WATCH 301...

   VALID 160129Z - 160300Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 301
   CONTINUES.

   SUMMARY...A SEVERE THREAT IS EXPECTED TO PERSIST THROUGH LATE
   EVENING ACROSS PARTS OF WY...SE ID AND NRN UT. WIND DAMAGE AND
   ISOLATED LARGE HAIL SHOULD BE THE PRIMARY THREATS ALTHOUGH A BRIEF
   TORNADO CAN NOT BE RULED OUT.

   DISCUSSION...LATEST WATER VAPOR SHOWS A SHORTWAVE TROUGH AND A
   WELL-DEFINED VORITICY MAX OVER NRN NV. AT THE SFC...A LOW IS PRESENT
   OVER NW UT WITH BACKED SELY FLOW ACROSS SE ID AND PARTS OF SWRN WY
   WHICH IS HELPING TO ENHANCE LOW-LEVEL CONVERGENCE NEAR THE ID-WY
   STATE LINE. THIS COMBINED WITH INCREASING LARGE-SCALE ASCENT
   ASSOCIATED WITH THE APPROACHING SHORTWAVE TROUGH SHOULD RESULT IN A
   GRADUAL INCREASE IN CONVECTIVE COVERAGE OVER THE NEXT FEW HOURS AS
   IS SUPPORTED BY THE HRRR. THE 00Z SOUNDING AT RIVERTON SHOWS SBCAPE
   JUST ABOVE 1200 J/KG WITH 700-500 MB LAPSE RATE NEAR 8.0 C/KM AND
   0-6 KM SHEAR AROUND 55 KT. THIS ENVIRONMENT SHOULD BE FAVORABLE FOR
   SUPERCELLS WITH ISOLATED LARGE HAIL. A BRIEF TORNADO CAN NOT BE
   RULED OUT. AS CELLS GRADUALLY INCREASE IN COVERAGE AND MOVE EWD INTO
   WRN AND CNTRL WY OVER THE NEXT FEW HOURS...WIND DAMAGE WILL ALSO BE
   POSSIBLE ESPECIALLY IF CELLS CAN CONGEAL INTO A SEMI-LINEAR
   STRUCTURE.

   ..BROYLES/MEAD.. 06/16/2015


   ATTN...WFO...UNR...BOU...CYS...BYZ...RIW...GJT...TFX...SLC...
   PIH...

   LAT...LON   40980403 40990995 40780995 40801017 40791051 40681094
               40541109 40571135 40691144 40501178 40431194 40471217
               40401217 40111215 39981221 39911242 39921401 42001401
               41931301 42561298 42551320 42721324 43031320 43091321
               43101296 43271296 43311285 43441290 43431279 43541278
               43521268 44041266 44061223 43971206 43971187 43881172
               43931139 43931111 43961103 44671105 44651069 44591062
               44561031 44301024 44011006 43900987 43790977 43930961
               43980951 43880938 43800925 43810909 43910908 43900891
               44000891 44020873 44070875 44100855 44180857 44150710
               44380713 44470731 44570734 44540602 43500602 43480494
               42620489 42610407 40980403