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WWUS20 KWNS 171750

SEL1

SPC WW 171750

MNZ000-NDZ000-172200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 651

NWS STORM PREDICTION CENTER NORMAN OK

1250 PM CDT SUN JUL 17 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHWEST MINNESOTA

       EAST CENTRAL NORTH DAKOTA



EFFECTIVE THIS SUNDAY AFTERNOON FROM 1250 PM UNTIL 500 PM CDT.



TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 45 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 60 MILES WEST SOUTHWEST OF

GRAND FORKS NORTH DAKOTA TO 15 MILES SOUTHEAST OF BEMIDJI

MINNESOTA.  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...LONG-LIVED SUPERCELL CONTINUES TO MOVE EWD/ESEWD ALONG

A WEAK SURFACE BOUNDARY INTO E CENTRAL ND.  THE LOW LEVELS HAVE

CONTINUED TO DESTABILIZE...WITH MLCAPE NOW IN EXCESS OF 5000 J/KG

WITH DIMINISHING CONVECTIVE INHIBITION.  THE INSTABILITY/DEEP-LAYER

SHEAR COMBINATION WILL CONTINUE TO SUPPORT SUPERCELLS...WHILE THE

EXTREME INSTABILITY/RICH MOISTURE AND CORRIDOR OF ENHANCED LOW-LEVEL

SHEAR NEAR THE BOUNDARY WILL SUPPORT A RISK FOR A FEW TORNADOES THIS

AFTERNOON.  ALSO...THERE WILL STILL BE THE POTENTIAL FOR THE

CONVECTION TO GROW UPSCALE INTO A BOWING MCS...WITH AN ACCOMPANYING

RISK FOR DAMAGING WINDS.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

650. MEAN STORM MOTION VECTOR 28035.





...THOMPSON

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