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095 

WWUS20 KWNS 242333

SEL2

SPC WW 242333

MTZ000-250700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 442

NWS STORM PREDICTION CENTER NORMAN OK

525 PM MDT WED JUL 24 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN AND EASTERN MONTANA



* EFFECTIVE THIS WEDNESDAY AFTERNOON AND THURSDAY MORNING FROM

  525 PM UNTIL 100 AM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES NORTH OF

SIDNEY MONTANA TO 50 MILES SOUTH SOUTHWEST OF CUT BANK MONTANA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU2).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 441...



DISCUSSION...TSTMS HAVE FORMED IN NE MT IN THE PAST 2 HOURS...IN

ZONE OF LOW-LVL ASCENT AND INSTABILITY ALONG AND N OF WEAK WNW-ESE

COLD FRONT. ADDITIONAL STORMS ARE EXPECTED TO CONTINUE FORMING IN

THE REGION...MOVING/DEVELOPING ESE WITH THE FRONT. FARTHER W...A

SEPARATE AREA OF SLIGHTLY POST-FRONTAL STORMS IS PRESENT ATTM ALONG

THE ERN SLOPES OF THE RCKYS IN SW AB. THIS ACTIVITY SHOULD DEVELOP

SEWD ALONG THE ERN SLOPES OF THE MOUNTAINS AND ADJACENT HIGH PLNS

INTO N CNTRL MT AS THE FRONT CONTINUES SLOWLY SWD...WITH THE

ACTIVITY FED BY ENHANCED UPSLOPE FLOW/MOISTURE TRANSPORT IN THE WAKE

OF THE BOUNDARY.

AS THE ENTIRE WW REGION WILL BE IN ZONE OF LARGE SCALE ASCENT AND

MODERATE DEEP SHEAR DOWNSTREAM FROM UPR IMPULSE CROSSING

AB/SK...SETUP MAY YIELD ADDITIONAL SCTD SUPERCELLS WITH A RISK FOR

LARGE HAIL...LOCALLY DMGG WIND...AND PERHAPS AN ISOLD TORNADO.

THE 01Z CONVECTIVE OTLK WILL BE ISSUED SLIGHTLY EARLY AND INCLUDE

PARTS OF THE NRN HIGH PLNS IN A SLIGHT RISK AREA.



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 30030.





...CORFIDI

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