

719 

WWUS20 KWNS 041555

SEL1

SPC WW 041555

ARZ000-LAZ000-MSZ000-TXZ000-CWZ000-042300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 91

NWS STORM PREDICTION CENTER NORMAN OK

1055 AM CDT MON APR 4 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EXTREME SOUTHEAST ARKANSAS

       SOUTHERN LOUISIANA

       CENTRAL MISSISSIPPI

       EXTREME SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS MONDAY MORNING AND EVENING FROM 1055 AM UNTIL 600

PM 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 125 STATUTE

MILES EAST AND WEST OF A LINE FROM 50 MILES WEST NORTHWEST OF

COLUMBUS MISSISSIPPI TO 35 MILES SOUTH SOUTHWEST OF LAKE CHARLES

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 87...WW 88...WW 89...WW

90...



DISCUSSION...WELL-DEVELOPED SQUALL ALONG THE COLD FRONT WILL

PROGRESS EWD AND PERSIST THROUGH THE AFTERNOON.  A CONTINUED FEED OF

66-72 F DEWPOINTS AND MODEST SURFACE HEATING WILL RESULT IN MODERATE

INSTABILITY AHEAD OF THE LINE...WHILE DEEP-LAYER SWLY FLOW WILL

PROVIDE SUFFICIENT VERTICAL SHEAR FOR ORGANIZED/EMBEDDED BOWS AND

POSSIBLY SOME SUPERCELL STRUCTURES.  DAMAGING WINDS WILL BE THE MAIN

THREAT...THOUGH A FEW TORNADOES WILL ALSO BE POSSIBLE WITH

CIRCULATIONS EMBEDDED IN THE LINE.



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 26040.





...THOMPSON

