

545 

WWUS20 KWNS 100000

SEL7

SPC WW 100000

MTZ000-100700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 597

NWS STORM PREDICTION CENTER NORMAN OK

600 PM MDT MON AUG 9 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN MONTANA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 600 PM UNTIL

100 AM MDT.



HAIL TO 1.5 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 65 MILES NORTHWEST OF

WILLISTON NORTH DAKOTA TO 25 MILES SOUTH OF MILES CITY MONTANA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 595...WW 596...



DISCUSSION...STRONG TO SVR TSTMS...AND POSSIBLY A COUPLE

SUPERCELLS...EXPECTED OVER ERN MT THIS EVE THROUGH EARLY TUE AS

LARGE SCALE ASCENT INCREASES AHEAD OF EJECTING UPR IMPULSE NOW IN

ERN ID/WRN WY.  SHALLOW NELY LOW LVL FLOW AND FAIRLY STEEP LOW LVL

LAPSE RATES OVER ERN MT SHOULD ENHANCE NEWD PROPAGATION OF

STORMS...WHERE DEEP WIND PROFILES SHOULD BE SUPPORTIVE OF BOWING

SEGMENTS WITH HIGH WIND/ MARGINALLY SVR HAIL.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 22030.





...CORFIDI

