

213 

WWUS20 KWNS 262224

SEL8

SPC WW 262224

MTZ000-270600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 808

NWS STORM PREDICTION CENTER NORMAN OK

420 PM MDT FRI AUG 26 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTH CENTRAL THROUGH SOUTHWEST AND SOUTH CENTRAL MONTANA



EFFECTIVE THIS FRIDAY AFTERNOON FROM 420 PM UNTIL MIDNIGHT 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 35 MILES NORTHEAST OF

CUT BANK MONTANA TO 60 MILES SOUTH SOUTHWEST OF BILLINGS MONTANA.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU8).



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.



DISCUSSION...TSTMS SHOULD CONTINUE TO INCREASE OVER THE HIGHER

TERRAIN OF WRN MT OVER THE NEXT SEVERAL HOURS...WITH THE STORMS

SUBSEQUENTLY MOVING MAINLY E ACROSS THE HIGH PLNS.  MOISTURE WILL

REMAIN MODEST.../WITH SFC DEW POINTS AVERAGING IN THE UPR 40S F AND

PW VALUES AROUND .8 - .9 INCH/...BUT SUFFICIENT FOR SUSTAINED

UPDRAFTS GIVEN STEEP LOW TO MID LVL LAPSE RATES...LIGHT LOW LVL ESE

FLOW...AND 35-40 KT WLY WINDS AT MID LVLS.  POTENTIAL FOR

DEVELOPMENT MAY BE FURTHER ENHANCED BY UPR IMPULSE MOVING EWD FROM

ID.  OVERALL SETUP APPEARS FAVORABLE FOR A FEW SUSTAINED MULTICELLS

AND SUPERCELLS...WITH AN ATTENDANT RISK FOR HIGH WIND AND POSSIBLY

SVR HAIL THROUGH LATE EVE.



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 26035.





...CORFIDI

