MESOSCALE DISCUSSION 1064

        MESOSCALE DISCUSSION 1064     NWS STORM PREDICTION CENTER NORMAN OK     0922 PM CDT MON JUN 04 2012          AREAS AFFECTED...N-CNTRL/NERN MT          CONCERNING...TORNADO WATCH 355...          VALID 050222Z - 050345Z          THE SEVERE WEATHER THREAT FOR TORNADO WATCH 355 CONTINUES.          SUMMARY...PRIMARY NEAR-TERM SEVERE THREAT EXISTS WITH SUPERCELL     STRUCTURE EMBEDDED WITHIN A TSTM CLUSTER CENTERED OVER CHOUTEAU     COUNTY. MONITORING ITS EVOLUTION FOR ITS POTENTIAL AFFECT ON     PORTIONS OF NERN MT AND POSSIBLE WW ISSUANCE.          DISCUSSION...INTENSE TSTM CLUSTER CENTERED OVER CHOUTEAU COUNTY HAS     HAD A HISTORY OF REPORTED SIGNIFICANT SEVERE HAIL AND SEVERE WIND     GUSTS. TORNADIC THREAT ASSOCIATED WITH THIS STORM SHOULD CONTINUE TO     INCREASE AS IT BEGINS TO INGEST UPPER 50S SURFACE DEW POINTS AMIDST     ENLARGING CYCLONIC HODOGRAPHS. CURRENT EXTRAPOLATION WILL TAKE THIS     CELL E/NEWD...THAT IF MAINTAINED...MAY GRAZE PORTIONS OF NERN MT     PRIOR TO MOVING INTO SASKATCHEWAN. FARTHER SE...CONVECTION ACROSS     S-CNTRL/SERN MT COULD INTENSIFY AS IT ENCOUNTERS THE LOW-LEVEL MOIST     AXIS ANCHORED ALONG THE UPPER MO VALLEY. BUT AS THE BOUNDARY LAYER     COOLS AND WITH STRONGER LARGE-SCALE ASCENT REMAINING FARTHER     WEST...THERE IS UNCERTAINTY OVER THIS SCENARIO WITH SEVERE POTENTIAL     LIKELY TO REMAIN MARGINAL OVER MOST OF ERN MT.          ..GRAMS.. 06/05/2012               ATTN...WFO...BYZ...GGW...TFX...