

960 

WWUS20 KWNS 201446

SEL2

SPC WW 201446

LAZ000-TXZ000-CWZ000-202200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 92

NWS STORM PREDICTION CENTER NORMAN OK

945 AM CDT TUE MAR 20 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN LOUISIANA

       EXTREME EAST CENTRAL AND SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 945 AM UNTIL

500 PM CDT.



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 40 STATUTE

MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH NORTHEAST OF

SHREVEPORT LOUISIANA TO 45 MILES SOUTH SOUTHEAST OF PORT ARTHUR

TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...N-S LINE OF THUNDERSTORMS WILL CONTINUE TO DRIFT EWD

FROM E TX INTO WRN LA IN ADVANCE OF A CLOSED LOW NEAR THE NM/TX

BORDER.  AN INFLUX OF BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S

WILL SUPPORT MODERATE INSTABILITY IN ADVANCE OF THE LINE...DESPITE

CLOUDS THAT WILL SLOW SURFACE HEATING SOMEWHAT.

ADDITIONALLY...LOW-LEVEL SLY SHEAR IS SUFFICIENT FOR CIRCULATIONS IN

THE LINE AND AN ATTENDANT RISK FOR A COUPLE OF TORNADOES AND

ISOLATED DAMAGING GUSTS THROUGH THE AFTERNOON.



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 500.

MEAN STORM MOTION VECTOR 21045.





...THOMPSON

