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000 

WWUS20 KWNS 162020

SEL0

SPC WW 162020

MTZ000-170400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 400

NWS STORM PREDICTION CENTER NORMAN OK

220 PM MDT SAT JUN 16 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL MONTANA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 220 PM UNTIL

1000 PM MDT.



TORNADOES...HAIL TO 3 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 105 STATUTE

MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH NORTHEAST OF

GREAT FALLS MONTANA TO 65 MILES SOUTHWEST OF BILLINGS MONTANA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



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.



DISCUSSION...SEVERE THUNDERSTORMS WILL INCREASE IN COVERAGE AND

INTENSITY DURING THE NEXT HOUR OR SO AND SPREAD ENEWD THROUGH THE

EVENING. ENVIRONMENT STRONGLY FAVORS SUPERCELLS WITH VERY STRONG

SHEAR AND INCREASING MLCAPE THROUGH THE EARLY EVENING.  LARGE

HAIL...SOME EXCEEDING 2 INCHES IN DIAMETER...ALONG WITH ISOLATED

DAMAGING WINDS WILL BE COMMON WITH THESE STORMS.  TORNADO THREAT

WILL ALSO INCREASE INTO THE EARLY EVENING AS STORMS INTERACT WITH

ELY SURFACE WINDS AND RICHER LOW LEVEL MOISTURE ALREADY IN PLACE

OVER CENTRAL MT.  LATER THIS EVENING...ONE OR MORE BOW ECHO

COMPLEXES MAY EVOLVE INCREASING THE RISK OF DAMAGING WINDS.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 24025.





...EVANS

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