

641 

WWUS20 KWNS 021926

SEL3

SPC WW 021926

MTZ000-NEZ000-SDZ000-WYZ000-030300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 653

NWS STORM PREDICTION CENTER NORMAN OK

125 PM MDT WED JUL 2 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SMALL PART OF SOUTH CENTRAL MONTANA

       PARTS OF WESTERN NEBRASKA PANHANDLE

       PARTS OF SOUTHWESTERN SOUTH DAKOTA

       MUCH OF NORTHERN WYOMING



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 125 PM UNTIL

900 PM 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 85

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST

NORTHWEST OF CODY WYOMING TO 10 MILES SOUTHEAST OF CHADRON

NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 651...WW 652...



DISCUSSION...COMBINATION OF MOIST/UNSTABLE UNSLOPED FLOW AND 30-40

KT OF DEEP LAYER SHEAR SUPPORTS DEVELOPMENT OF SEVERE THUNDERSTORMS

THIS AFTERNOON.  STORMS WILL DEVELOP INITIALLY OVER HIGHER TERRAIN

AND THEN PROPAGATE SEWD WITH POTENTIAL FOR SUPERCELLS.  ALTHOUGH

THERE IS POTENTIAL FOR A BRIEF TORNADO OR TWO...PRIMARY THREAT WILL

BE LARGE HAIL AND DOWNBURSTS WINDS.



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 32020.





...HALES

