

000 

WWUS20 KWNS 221900

SEL6

SPC WW 221900

IDZ000-MTZ000-NVZ000-UTZ000-WYZ000-230300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 726

NWS STORM PREDICTION CENTER NORMAN OK

100 PM MDT TUE JUL 22 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       LARGE PART OF SOUTHERN IDAHO

       PARTS OF SOUTHWESTERN MONTANA

       PARTS OF NORTHEAST NEVADA

       NORTHWEST UTAH

       PARTS OF WESTERN WYOMING



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 100 PM UNTIL

900 PM 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 40 MILES WEST OF

DUGWAY UTAH TO 65 MILES EAST NORTHEAST OF DILLON MONTANA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU6).



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 724...WW 725...



DISCUSSION...THUNDERSTORMS WILL INCREASE IN NUMBER AND INTENSITY

ACROSS MUCH OF WATCH AREA AS A VERY MOIST AND INCREASINGLY UNSTABLE

AIRMASS IS AVAILABLE AHEAD OF OREGON UPPER TROUGH.  30-40KT OF SHEAR

COUPLED WITH MLCAPES AOA 1000 J/KG SUPPORT BOTH DAMAGING WINDS AND

LARGE HAIL.  POTENTIAL FOR ISOLATED SUPERCELLS LOCALLY ENHANCING

SEVERE THREAT INCLUDING POSSIBLE BRIEF TORNADOES.



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 23030.





...HALES

