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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 668

NWS STORM PREDICTION CENTER NORMAN OK

700 PM CDT WED OCT 17 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTHERN ARKANSAS

       NORTHERN AND CENTRAL LOUISIANA

       CENTRAL MISSISSIPPI

       NORTHEAST TEXAS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 700 PM

UNTIL 300 AM CDT.



TORNADOES...HAIL TO 1.5 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 145 STATUTE

MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH NORTHEAST OF

GREENVILLE MISSISSIPPI TO 45 MILES EAST SOUTHEAST OF NATCHITOCHES

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 666...WW 667...



DISCUSSION...TSTMS...INCLUDING A FEW SUPERCELLS...EXPECTED TO

DEVELOP SWD ALONG AND AHEAD OF NE-SW COLD FRONT NOW APPROACHING THE

ARKLATEX AS ASSOCIATED ERN OK SHORTWAVE TROUGH FURTHER AMPLIFIES ESE

ACROSS REGION. THE STRONGEST/LONGEST-LIVED STORMS WITH THE GREATEST

TORNADO RISK ARE EXPECTED ALONG NE-SW CONFLUENCE AXIS NOW EXTENDING

FROM JUST E OF SHREVEPORT TO E OF LITTLE ROCK. STORMS WILL BE

FAST-MOVING AND ULTIMATELY MAY OUT-RUN LOW-LVL MOIST AXIS IN ERN MS

EARLY THU. BUT WIND PROFILES AND KINEMATIC ENVIRONMENT SUGGEST GOOD

LIKELIHOOD FOR SUBSTANTIAL MID-LVL STORM ROTATION. THUS...SVR

RISK/TORNADO POTENTIAL MAY EXTEND A BIT E OF THE MORE

SLOWLY-ADVANCING MOIST AXIS IN MS.



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

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

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

500. MEAN STORM MOTION VECTOR 29035.





...CORFIDI

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