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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 651

NWS STORM PREDICTION CENTER NORMAN OK

350 PM MDT THU SEP 9 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN NORTH DAKOTA

       NORTHWEST AND NORTH CENTRAL SOUTH DAKOTA



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 350 PM UNTIL

1100 PM MDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 65 MILES WEST NORTHWEST OF

DICKINSON NORTH DAKOTA TO 40 MILES SOUTH OF BISMARCK NORTH

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 650...



DISCUSSION...AREA OF BACKED/MODERATELY STRONG LOW LVL FLOW EXPECTED

TO PERSIST INVOF NW-SE ORIENTED WARM FRONT FROM W CNTRL ND INTO N

CNTRL SD THIS EVE.  CONTINUED EWD ADVANCE OF WRN STATES UPR TROUGH

AND SFC HEATING SHOULD SUPPORT ADDITIONAL SFC-BASED STORM

DEVELOPMENT IN PLUME OF DEEPLY-MIXED AIR EXTENDING FROM ERN WY/WRN

SD NNE INTO SW ND.  AS THE STORMS MOVE NNE WITHIN STRENGTHENING

MID/UPR LVL FLOW...POTENTIAL MAY INCREASE FOR LOW LVL STORM ROTATION

AS POSSIBLE TORNADOES AS THE UPDRAFTS ENCOUNTER AND/OR MOVE IN

TANDEM WITH WARM FRONT.



AVIATION...TORNADOES AND 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 24035.





...CORFIDI

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