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684 

WWUS20 KWNS 062346

SEL5

SPC WW 062346

MTZ000-070700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 435

NWS STORM PREDICTION CENTER NORMAN OK

545 PM MDT MON JUN 6 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL MONTANA



EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 545 PM

UNTIL 100 AM MDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE

MILES EAST AND WEST OF A LINE FROM 85 MILES NORTHEAST OF

LEWISTOWN MONTANA TO 55 MILES SOUTH OF BILLINGS MONTANA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU5).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 433...WW 434...



DISCUSSION...CONSIDERABLE STRENGTHENING OF FORCING FOR ASCENT AND

DEEP-LAYER WIND FIELD IS FORECAST IN THE 07/00-03Z TIME

FRAME...SUPPORTING A MARKED INCREASE IN STORM COVERAGE AND

INTENSITY.  THE PRESENCE OF BOUNDARY LAYER DEWPOINTS IN THE

50S...STEEP LAPSE RATES AND PRONOUNCED VEERING OF WINDS WITH HEIGHT

WILL FOSTER AN ENVIRONMENT FAVORABLE FOR SUPERCELLS CAPABLE OF LARGE

HAIL AND A FEW TORNADOES.



AVIATION...TORNADOES AND 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 21030.





...MEAD

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