SPC Severe Thunderstorm Watch 431

WW 431 SEVERE TSTM MT 261720Z - 262300Z
URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 431 NWS STORM PREDICTION CENTER NORMAN OK 1120 AM MDT TUE JUN 26 2012 THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF NORTHWEST AND NORTH CENTRAL MONTANA EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 1120 AM UNTIL 500 PM MDT. HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE MILES EITHER SIDE OF A LINE FROM 70 MILES SOUTH SOUTHWEST OF CUT BANK MONTANA TO 40 MILES EAST OF HAVRE MONTANA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1). REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. DISCUSSION...STRONG STORMS HAVE DEVELOPED IN A BAND ALONG THE LEADING EDGE OF INTENSE LARGE SCALE ASCENT ASSOCIATED WITH AN UPPER SHORT WAVE TROUGH MOVING NEWD ACROSS THE NRN INTERMOUNTAIN REGION. STEEP LAPSE RATES AND INCREASING MOISTURE WITH EWD EXTENT WILL SUPPORT STRONG/SEVERE STORMS WITH POTENTIAL TO PRODUCE LARGE HAIL AND DAMAGING WINDS. AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR 22035. ...WEISS Read more

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