PORTIONS OF WW 354 IN W/N-CNTRL MT WILL BE UPGRADED TO A TORNADO WATCH

        MESOSCALE DISCUSSION 1059     NWS STORM PREDICTION CENTER NORMAN OK     0628 PM CDT MON JUN 04 2012          AREAS AFFECTED...W/N-CNTRL MT          CONCERNING...SEVERE THUNDERSTORM WATCH 354...          VALID 042328Z - 050030Z          THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 354     CONTINUES.          SUMMARY...PORTIONS OF WW 354 IN W/N-CNTRL MT WILL BE UPGRADED TO A     TORNADO WATCH BY 00Z.          DISCUSSION...A COUPLE OF SUPERCELLS CROSSING THE CONTINENTAL DIVIDE     SHOULD PROGRESS INTO AN INCREASINGLY FAVORABLE AIR MASS FOR     POTENTIAL TORNADIC DEVELOPMENT BY EARLY EVENING. ALTHOUGH SURFACE     DEW POINT DEPRESSIONS AROUND 25 TO 35 DEG F AT GTF/HLN ARE CURRENTLY     A MITIGATING FACTOR TO TORNADIC POTENTIAL...SURFACE DEW POINTS HAVE     INCREASED INTO THE MIDDLE TO UPPER 50S AT HVR TO LWT. WITH LOW-LEVEL     ELYS EXPECTED TO STRENGTHEN WITH APPROACH OF SHORT WAVE TROUGH OVER     NRN CA...ADVECTION OF RICHER LOW-LEVEL MOISTURE COMBINED WITH     INCREASING LOW-LEVEL SHEAR WILL INCREASE THE TORNADIC RISK THIS     EVENING.          ..GRAMS.. 06/04/2012               ATTN...WFO...BYZ...GGW...TFX...MSO...