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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 438

NWS STORM PREDICTION CENTER NORMAN OK

140 PM MDT FRI JUL 2 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND NORTHEAST MONTANA



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 140 PM UNTIL

1100 PM 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 100

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH

NORTHEAST OF GLASGOW MONTANA TO 55 MILES SOUTH SOUTHEAST OF

LIVINGSTON MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY THIS AFTERNOON AS A COLD FRONT MOVES EAST ACROSS CENTRAL

AND NORTHEAST MT. VERY WARM AND UNSTABLE CONDITIONS AHEAD OF THE

FRONT WILL FOSTER ROBUST AND LONG-LIVED THUNDERSTORMS. GIVEN

STRENGTHENING MID LEVEL FLOW OF UP TO 50KT...EXPECT STORMS TO BE

WELL ORGANIZED AND INCLUDE SUPERCELLS...WITH THE PROSPECT OF LARGE

HAIL...AS WELL AS LINE SEGMENTS CAPABLE OF PRODUCING LOCALLY

DAMAGING WIND GUSTS.

CONVECTION WAS ALREADY INITIATING ACROSS THE HIGHER TERRAIN OF

SOUTHWEST MT WHERE OROGRAPHIC AND FRONTAL LIFT HAVE OVERCOME

INHIBITION. EXPECT ADDITIONAL DEVELOPMENT NEXT FEW HOURS AS THE

FRONT MOVES INTO CENTRAL MT. DRIER AIRMASS EMANATING FROM WY...MAY

INHIBIT DEVELOPMENT ACROSS SOUTH-CENTRAL MT. HOWEVER...ANY STORMS

MOVING ACROSS THIS AREA LATER WILL POSE SOME THREAT FOR DAMAGING

WINDS GIVEN DEEPLY MIXED AND HOT BOUNDARY LAYER AIRMASS EXPECTED.

ADDITIONAL...PERHAPS LINEAR DEVELOPMENT...MAY OCCUR LATER TODAY AND

INTO TONIGHT AS THE COLD FRONT MOVES INTO NERN MT. SOME GUIDANCE

SUGGESTS STORM MAY ACTUALLY FORM IMMEDIATELY BEHIND THE FRONTAL WIND

SHIFT. NONETHELESS...THIS ACTIVITY COULD STILL PRODUCE HAIL AND

GUSTY WINDS IN THESE AREAS THROUGH THE EVENING.



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.





...CARBIN

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