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WWUS20 KWNS 010549

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 820

NWS STORM PREDICTION CENTER NORMAN OK

1250 AM CDT THU SEP 1 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST MINNESOTA

       NORTHEAST AND EAST CENTRAL NORTH DAKOTA



EFFECTIVE THIS THURSDAY MORNING FROM 1250 AM UNTIL 700 AM CDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 95

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH OF

HALLOCK MINNESOTA TO 55 MILES SOUTH SOUTHEAST OF GRAND FORKS

NORTH DAKOTA.  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 819...



DISCUSSION...BOWING LINE OF STRONG THUNDERSTORMS IS MOVING RAPIDLY

ENEWD OVER CENTRAL ND.  THIS CONVECTIVE MESOSYSTEM IS EXPECTED TO

PROGRESS TOWARD THE RED RIVER AND INTO NWRN MN BY 09Z WITH A

CONTINUED THREAT FOR DAMAGING WIND GUSTS AND ISOLATED LARGE

HAIL...SUPPORTED BY 40-50 KT SWLY FLOW ALOFT AND A STRONG SSWLY LOW

LEVEL JET.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

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

MOTION VECTOR 24045.





...WEISS

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