

287 

WWUS20 KWNS 212156

SEL0

SPC WW 212156

MTZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 370

NWS STORM PREDICTION CENTER NORMAN OK

355 PM MDT MON JUN 21 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EASTERN MONTANA



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 355 PM UNTIL 900

PM MDT.



TORNADOES...HAIL TO 2.5 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 75 STATUTE

MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH OF WOLF POINT

MONTANA TO 50 MILES WEST SOUTHWEST OF GLENDIVE 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.



OTHER WATCH INFORMATION...CONTINUE...WW 367...WW 368...WW 369...



DISCUSSION...UPPER LOW AND ASSOCIATED 60 KT UPPER LEVEL JET MAX

MOVING INTO ERN MT HAS RESULTED IN SUFFICIENT LIFT FOR THUNDERSTORMS

TO DEVELOP. THESE STORMS SHOULD INCREASE IN COVERAGE INTO THE

EVENING HOURS. SHEAR AND INSTABILITY ARE FAVORABLE FOR SUPERCELLS

WITH TORNADOES AND LARGE HAIL.



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

SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE

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

450. MEAN STORM MOTION VECTOR 24025.





...IMY

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