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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 537

NWS STORM PREDICTION CENTER NORMAN OK

520 PM CDT MON JUL 26 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN MONTANA

       WESTERN AND NORTH-CENTRAL NORTH DAKOTA

       NORTHWEST SOUTH DAKOTA



EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 520 PM

UNTIL 300 AM CDT.



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 90

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

WILLISTON NORTH DAKOTA TO 40 MILES WEST SOUTHWEST OF BUFFALO

SOUTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 536...



DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY THIS EVENING ALONG W-E ORIENTED FRONT IN PLACE FROM NERN

MT INTO N-CNTRL ND...AS WELL AS ALONG PRE-FRONTAL WIND SHIFT

/ORIENTED N-S/ ACROSS ERN MT.  FORCING FOR ASCENT ATTENDANT TO

MIDLEVEL IMPULSE TRANSLATING INTO NERN MT IN CONJUNCTION WITH A

MODERATELY UNSTABLE AIR MASS /I.E. MLCAPE OF 2000-3000 J PER KG/ AND

40-50 KT OF DEEP NWLY SHEAR SHOULD YIELD ORGANIZED STORM

DEVELOPMENT...INCLUDING SUPERCELLS WITH THE THREAT FOR MAINLY LARGE

HAIL AND DAMAGING WIND GUSTS.



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 550. MEAN STORM

MOTION VECTOR 28025.





...MEAD

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