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536 

WWUS20 KWNS 222241

SEL3

SPC WW 222241

NDZ000-SDZ000-230700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 673

NWS STORM PREDICTION CENTER NORMAN OK

535 PM CDT FRI JUL 22 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN AND SOUTHERN NORTH DAKOTA

       NORTHERN SOUTH DAKOTA



EFFECTIVE THIS FRIDAY AFTERNOON AND SATURDAY MORNING FROM 535 PM

UNTIL 200 AM 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 90 STATUTE

MILES EAST AND WEST OF A LINE FROM 70 MILES NORTHWEST OF MINOT

NORTH DAKOTA TO 55 MILES SOUTH OF LEMMON SOUTH DAKOTA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU3).



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 670...WW 671...WW 672...



DISCUSSION...TSTMS ARE BEGINNING TO FORM ALONG WNW/ESE ORIENTED WARM

FRONT IN  S CNTRL ND.  MODERATE TO STRONGLY VEERING LOW LVL WIND

PROFILES IN THIS REGION...STEEP LOW LVL LAPSE RATES...AND PRESENCE

OF AMPLE MOISTURE SUGGEST POTENTIAL FOR SUPERCELLS WITH

TORNADOES...IN ADDITION TO VERY LARGE HAIL/LOCALLY DMGG WIND.  WITH

TIME...BROKEN BAND OF STORMS WITH EMBEDDED SUPERCELLS NOW IN ERN MT

EXPECTED TO MOVE INTO WRN ND AS ASSOCIATED UPR LVL JET STREAK

CONTINUES NEWD.  THIS ACTIVITY MAY EVOLVE INTO A LARGER SCALE BOW

MCS...POSSIBLY YIELDING A MORE WIDESPREAD DMGG WIND THREAT...IN

ADDITION TO A CONTINUING RISK FOR ISOLD TORNADOES/SVR HAIL INTO LATE

TNGT/EARLY SAT.



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

600. MEAN STORM MOTION VECTOR 24020.





...CORFIDI

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