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119 

WWUS20 KWNS 201849

SEL9

SPC WW 201849

ARZ000-LAZ000-MSZ000-TXZ000-210200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 9

NWS STORM PREDICTION CENTER NORMAN OK

1250 PM CST THU FEB 20 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  PARTS OF EASTERN ARKANSAS

  CENTRAL AND NORTHERN LOUISIANA

  PARTS OF WESTERN MISSISSIPPI

  PARTS OF EAST CENTRAL AND SOUTHEAST TEXAS



* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1250 PM

  UNTIL 800 PM CST.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE

  A FEW TORNADOES POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 105

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES EAST

SOUTHEAST OF LUFKIN TEXAS TO 60 MILES NORTH NORTHEAST OF

GREENVILLE MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



&&



DISCUSSION...PRE-FRONTAL STORMS WILL CONTINUE TO INTENSIFY IN A

NE-SW BAND FROM E TX INTO SE AR THROUGH THE AFTERNOON.  INSTABILITY

AND DEEP-LAYER VERTICAL SHEAR WILL BE SUFFICIENT FOR A RISK OF

DAMAGING WINDS AND ISOLATED LARGE HAIL WITH THE STRONGEST EMBEDDED

LINE SEGMENTS/CELLS...SOME OF WHICH COULD HAVE SUPERCELL STRUCTURE.

WHILE A TORNADO OR TWO CANNOT BE RULED OUT...THE TENDENCY FOR MORE

LINEAR CONVECTION AND WEAKENING LOW-LEVEL SHEAR WITH A NOTED

VEER-BACK SIGNATURE AROUND 700 MB ALL SUGGEST THAT TORNADOES SHOULD

NOT BE THE PRIMARY THREAT.



AVIATION...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 24040.





...THOMPSON

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