MESOSCALE DISCUSSION 1101 NWS STORM PREDICTION CENTER NORMAN OK 0607 PM CDT FRI JUN 08 2012 AREAS AFFECTED...N-CNTRL AND NERN MT / FAR NWRN ND CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 082307Z - 090000Z PROBABILITY OF WATCH ISSUANCE...60 PERCENT SUMMARY...STORMS ARE EXPECTED TO CONTINUE TO DEVELOP/INTENSIFY THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS. IT APPEARS INCREASINGLY PROBABLE THAT A DEVELOPING ISOLD LARGE HAIL/SEVERE WIND RISK WILL EVENTUALLY NECESSITATE A SEVERE WW. DISCUSSION...LONG LOOP OF WATER VAPOR IMAGERY SHOWS AN UPPER LOW CONTINUING TO SLIDE EWD FROM THE ERN PACIFIC INTO THE PACIFIC NW...AND THIS IS CONTRIBUTING TO MORE APPRECIABLE MID LEVEL HEIGHT FALLS OVERSPREADING ERN MT/WRN ND. IN THE LOW LEVELS...A NORTH TO SOUTH BAROCLINIC ZONE EXTENDS FROM NEAR THE ALBERTA/SASKATCHEWAN/MT BORDER SWD TO A LOW INVOF THE UT/WY BORDER. TO THE E OF THE FRONT...ELY FLOW HAS ADVECTED LOW TO MID 50S DEWPOINTS INTO THE REGION AND HAS AIDED IN DESTABILIZING THE AIRMASS ACROSS THE DISCUSSION AREA. FOCUSED CONVERGENCE/FRONTAL FORCING AND FURTHER HEATING HAS CONSIDERABLY WEAKENED THE EXISTING CAP ACROSS CNTRL MT BY 23Z...IMPLIED BY BUILDING CU/REFLECTIVITY FIELD INVOF THE BOUNDARY. SHORT-TERM MODEL GUIDANCE GENERALLY SHOWS STORMS DEVELOPING AND INCREASING IN AREAL COVERAGE/INTENSITY IN THE 00-03Z PERIOD. AS STORMS MATURE...STRONG DEEP LAYER SHEAR WILL ACT TO ORGANIZE INITIALLY ISOLD ACTIVITY INTO A GROWING CLUSTER OF STORMS AS FRONTAL FORCING/WAA INCREASE DURING THIS TIMEFRAME. THE MAIN HAZARDS WITH THIS ACTIVITY WILL BE ISOLD LARGE HAIL/SEVERE WIND GUSTS AS STORMS MOVE FROM NERN MT INTO WRN ND TOWARDS THE OVERNIGHT. GIVEN A SUPERCELLULAR WIND PROFILE AND AN INITIALLY ISOLD EXPECTED STORM MODE...THERE IS A 1-2 HR PERIOD IN WHICH A WEAK TORNADO CANNOT BE RULED OUT AROUND DUSK AS TEMP/DEWPOINT SPREADS DECREASE WITHIN A SUFFICIENTLY SHEARED LOW LEVEL ELY FLOW REGIME. ..SMITH/THOMPSON.. 06/08/2012 ATTN...WFO...BIS...BYZ...GGW...TFX...
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