

000 

WWUS20 KWNS 121719

SEL6

SPC WW 121719

ARZ000-LAZ000-OKZ000-TXZ000-CWZ000-130100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 16

NWS STORM PREDICTION CENTER NORMAN OK

1115 AM CST MON FEB 12 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN ARKANSAS

       WESTERN AND CENTRAL LOUISIANA

       FAR SOUTHEAST OKLAHOMA

       EAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS MONDAY MORNING AND EVENING FROM 1115 AM UNTIL 700

PM CST.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH

NORTHWEST OF TEXARKANA ARKANSAS TO 40 MILES SOUTHEAST OF PORT

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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...TSTMS EXPECTED TO STRENGTHEN THROUGH THE AFTERNOON

ALONG N/S CONFLUENCE ZONE IN E TX.  CONFLUENCE ZONE AND STORMS

SHOULD SHIFT SLOWLY ENE THROUGH THIS EVENING...WITH MOISTENING

BOUNDARY LAYER AND SFC HEATING CONTRIBUTING TO SUFFICIENT SBCAPE FOR

A HAIL AND HIGH WIND THREAT...ESPECIALLY WITH EMBEDDED ROTATING

UPDRAFTS.

WITH TIME...GREATER DESTABILIZATION AND BACKED LOW LEVEL FLOW MAY

POSE AN ENHANCED THREAT FOR LOW-LEVEL STORM ROTATION/POSSIBLE

TORNADOES WITH LIKELY SLIGHTLY-MORE-DISCRETE ACTIVITY IN SRN PART OF

LINE SSW TO THE MIDDLE TX GULF CST.  THIS REGION MAY REQUIRE UPGRADE

TO/ADDITION OF A TORNADO WATCH BY MID AFTERNOON.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM

MOTION VECTOR 23030.





...CORFIDI

