

830 

WWUS20 KWNS 070124

SEL8

SPC WW 070124

MTZ000-070700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 558

NWS STORM PREDICTION CENTER NORMAN OK

725 PM MDT MON JUL 6 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEASTERN MONTANA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 725 PM UNTIL

100 AM MDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 95

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH

NORTHEAST OF GLASGOW MONTANA TO 60 MILES WEST SOUTHWEST OF

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 553...WW 554...WW

555...WW 556...WW 557...



DISCUSSION...STRONG UPPER TROUGH WILL PUSH A LINE OF THUNDERSTORMS

EASTWARD  ACROSS NORTHEASTERN MT OVERNIGHT. ALTHOUGH THIS AREA IS

LOCATED NORTH OF WARM FRONT IN SERN MT...STRONG ELY BOUNDARY LAYER

WINDS AND MODERATE INSTABILITY ARE LIKELY TO ENHANCE THE FORWARD

SPEED OF THE SYSTEM AND POTENTIAL FOR DAMAGING WINDS.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 23030.





...IMY

