

000 

WWUS20 KWNS 222123

SEL0

SPC WW 222123

MTZ000-WYZ000-230500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 730

NWS STORM PREDICTION CENTER NORMAN OK

325 PM MDT TUE JUL 22 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN MONTANA

       NORTH CENTRAL WYOMING



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 325 PM UNTIL

1100 PM MDT.



HAIL TO 2 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST

SOUTHWEST OF LIVINGSTON MONTANA TO 35 MILES SOUTH SOUTHEAST OF

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 725...WW 726...WW

727...WW 728...WW 729...



DISCUSSION...A VERY WARM AND MOIST AIR MASS IS IN PLACE ACROSS THE

REGION AHEAD OF STRONG MID/UPPER LEVEL SYSTEM LIFTING NEWD INTO THE

NRN ROCKIES.  CONVECTION WILL LIKELY CONTINUE INCREASING ACROSS THE

AREA THROUGH THE EVENING AS THIS IMPULSE LIFTS INTO CENTRAL

MT...INCREASING DEEP LAYER SHEAR OVER SRN MT.  SUPERCELLS AND

ORGANIZED CLUSTERS/LINES WILL SPREAD ENEWD THROUGH THE EVENING WITH

ASSOCIATED THREATS OF LARGE HAIL AND DAMAGING WINDS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 25025.





...EVANS

