

000 

WWUS20 KWNS 040351

SEL5

SPC WW 040351

MTZ000-NDZ000-SDZ000-WYZ000-041100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 805

NWS STORM PREDICTION CENTER NORMAN OK

950 PM MDT SUN AUG 3 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN AND SOUTHERN MONTANA

       SOUTHWEST NORTH DAKOTA

       NORTHWEST SOUTH DAKOTA

       NORTHEAST WYOMING



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 950 PM UNTIL

500 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 125

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHEAST OF

MILES CITY MONTANA TO 55 MILES EAST OF GILLETTE WYOMING.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU5).



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 803...WW 804...



DISCUSSION...TSTMS FORMING ALONG ZONE OF ASCENT IN ENTRANCE REGION

OF MID/UPR LVL SPEED MAX CROSSING ERN MT EXPECTED TO SLOWLY INCREASE

IN STRENGTH THROUGH LATE TONIGHT AS ACTIVITY ENCOUNTERS INCREASING

MOISTURE WITH EWD EXTENT.  SEASONABLY STRONG DEEP UNIDIRECTIONAL WSW

FLOW AND STEEP CLOUD LAYER LAPSE RATES SUGGEST POTENTIAL FOR

SUSTAINED/ORGANIZED STORMS/POSSIBLE SUPERCELLS WITH HAIL/WIND.



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 27035.





...CORFIDI

