

666 

WWUS20 KWNS 070135

SEL0

SPC WW 070135

MTZ000-070800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 670

NWS STORM PREDICTION CENTER NORMAN OK

735 PM MDT THU AUG 6 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF NORTH CENTRAL AND NORTHEAST MONTANA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 735 PM

UNTIL 200 AM MDT.



HAIL TO 2.5 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 115 MILES WEST

SOUTHWEST OF GLASGOW MONTANA TO 35 MILES SOUTH SOUTHEAST OF WOLF

POINT MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 667...WW 668...WW 669...



DISCUSSION...SEVERE THUNDERSTORMS CONTINUE TO DEVELOP/MOVE EWD INTO

A MOIST AND UNSTABLE AIR MASS ACROSS THE WATCH AREA.  FAVORABLE DEEP

LAYER SHEAR WILL MAINTAIN THREAT FOR SHORT LINE SEGMENTS ENHANCING

THE WIND DAMAGE THREAT.



AVIATION...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 500. MEAN STORM

MOTION VECTOR 24030.





...HALES

