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WWUS20 KWNS 020346

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 437

NWS STORM PREDICTION CENTER NORMAN OK

940 PM MDT THU JUL 1 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME EASTERN MONTANA

       WESTERN NORTH DAKOTA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 940 PM

UNTIL 300 AM MDT.



HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 90

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH OF

WILLISTON NORTH DAKOTA TO 35 MILES SOUTHEAST OF BAKER MONTANA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 436...



DISCUSSION...BOWING MCS OVER ERN MT IS EXPECTED TO CONTINUE MOVING

EWD 30-35 KT INTO AN INCREASINGLY MOIST AND UNSTABLE ENVIRONMENT

WITH SURFACE DEWPOINTS IN THE MID/UPPER 60S AND MLCAPE TO 2000 J/KG.

ENELY LOW LEVEL WINDS COUPLED WITH SWLY MID LEVEL WINDS OF 30-40 KT

ARE RESULTING IN DEEP LAYER SHEAR OF 35-40 KT SUPPORTIVE OF

ORGANIZED CONVECTIVE STORMS INCLUDING ISOLATED SUPERCELLS AND BOWING

LINE SEGMENTS.  THREAT FOR DAMAGING WIND GUSTS AND LARGE HAIL WILL

CONTINUE FOR AT LEAST SEVERAL MORE HOURS TONIGHT.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 24030.





...WEISS

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