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000 

WWUS20 KWNS 022041

SEL2

SPC WW 022041

MTZ000-WYZ000-030500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 472

NWS STORM PREDICTION CENTER NORMAN OK

240 PM MDT MON JUL 2 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN MONTANA

       NORTHEAST WYOMING



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

1100 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 80

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTHWEST OF

HAVRE MONTANA TO 35 MILES SOUTH OF GILLETTE WYOMING.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU2).



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...TSTMS/SUPERCELLS EXPECTED TO FORM IN THE NEXT 1-2 HRS

IN THE LEE OF THE NRN RCKYS AS LARGE SCALE ASCENT WITH APPROACHING

UPR TROUGH AND SFC HEATING FURTHER DESTABILIZE REGION.  WEAK

CONVERGENCE AND ISOLATED SOURCES OF INITIATION PROVIDED BY TERRAIN

SUGGEST GOOD LIKELIHOOD FOR ACTIVITY TO REMAIN AT LEAST

SEMI-DISCRETE FOR SOME TIME...PERHAPS ENHANCING THREAT FOR LARGE

HAIL IN ADDITION TO HIGH WIND.

PARTS OF E CNTRL AND NE MT MAY REQUIRE A TORNADO WATCH A BIT LATER

THIS AFTN OR EVENING AS STORMS IN PRESENT WW INTERACT WITH

RELATIVELY MOIST ESE LOW LEVEL FLOW N OF STALLING OUTFLOW

BOUNDARY/FRONT.



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 26035.





...CORFIDI

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