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073 

WWUS20 KWNS 200141

SEL6

SPC WW 200141

ARZ000-KSZ000-MOZ000-OKZ000-TXZ000-200800-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 686

NWS STORM PREDICTION CENTER NORMAN OK

735 PM CST WED DEC 19 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN ARKANSAS

       EXTREME SOUTHEAST KANSAS

       SOUTHWEST MISSOURI

       EASTERN OKLAHOMA

       EXTREME NORTHEAST TEXAS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 735 PM

UNTIL 200 AM CST.



TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS

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



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH NORTHEAST OF

SPRINGFIELD MISSOURI TO 5 MILES EAST SOUTHEAST OF PARIS TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



DISCUSSION...STORMS ARE INTENSIFYING ALONG A DRY LINE FROM SOUTH

CENTRAL OK INTO FAR NORTH-CENTRAL TX...WITH LESS-ORGANIZED

CONVECTION DEVELOPING OVER NERN OK.  STORMS ARE LIKELY TO INCREASE

TONIGHT AS A STRONG COLD FRONT OVERTAKES THE DRY LINE AND BEGINS TO

SURGE EWD ACROSS THE AREA.  STRONG DYNAMIC FORCING FOR ASCENT

ASSOCIATED WITH AN INTENSE UPPER TROUGH MOVING INTO THE CENTRAL

PLAINS WILL ENHANCE FORCED LIFT ALONG THE COLD FRONT SUPPORTIVE OF

ADDITIONAL STRONG/SEVERE STORM DEVELOPMENT.  STRENGTHENING WINDS

ALOFT/DEEP LAYER SHEAR AND CLOCKWISE TURNING LOW-LEVEL HODOGRAPHS

FAVOR EMBEDDED SUPERCELL/QLCS STRUCTURES WITH DAMAGING WINDS AND

SEVERAL TORNADOES POSSIBLE TONIGHT.



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

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400.

MEAN STORM MOTION VECTOR 23045.





...WEISS

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