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045 

WWUS20 KWNS 082343

SEL3

SPC WW 082343

MTZ000-090700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 363

NWS STORM PREDICTION CENTER NORMAN OK

545 PM MDT FRI JUN 8 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EAST CENTRAL AND NORTHEAST MONTANA



EFFECTIVE THIS FRIDAY AFTERNOON AND SATURDAY MORNING FROM 545 PM

UNTIL 100 AM 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 100

STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH

NORTHEAST OF GLASGOW MONTANA TO 25 MILES WEST OF MILES CITY

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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...AN INCREASE IN COVERAGE/INTENSITY OF STORMS IS EXPECTED

THIS EVENING IN THE AREA W OF A LINE FROM GGW-MLS...ALONG A SURFACE

FRONT TO THE N OF A SURFACE LOW NEAR THE WY/MT BORDER...AS A

MIDLEVEL LOW MOVES EWD OVER THE NRN ROCKIES.  LOW-LEVEL MOISTURE

WILL CONTINUE TO SPREAD NWWD FROM THE DAKOTAS INTO ERN MT...WHERE

THE COMBINATION OF INSTABILITY/VERTICAL SHEAR WILL BE SUFFICIENT FOR

SUPERCELLS.  LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN SEVERE

THREATS THROUGH TONIGHT...THOUGH A TORNADO CANNOT BE RULED OUT LATE

THIS EVENING IN NE MT WHERE A DISCRETE STORM ENCOUNTERS A MORE MOIST

BOUNDARY LAYER IN THE GGW-GDV-JDN AREA.



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 500. MEAN STORM

MOTION VECTOR 25025.





...THOMPSON

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