Tornado Watch 71

Issued

Mar 26, 2009, 3:57 PM CDT (20:57 UTC)

Expired

Mar 26, 2009, 11:00 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

Two or more tornadoes

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 277Mar 26, 3:06 PM CDT
• Mesoscale Discussion 280Mar 26, 5:36 PM CDT
• Mesoscale Discussion 282Mar 26, 6:56 PM CDT
• Mesoscale Discussion 283Mar 26, 9:13 PM CDT

294 
WWUS20 KWNS 262059
SEL1  
SPC WW 262059
LAZ000-TXZ000-CWZ000-270400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 71
NWS STORM PREDICTION CENTER NORMAN OK
355 PM CDT THU MAR 26 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       NORTHERN AND SOUTHWEST LOUISIANA
       EAST CENTRAL AND SOUTHEAST TEXAS
       COASTAL WATERS

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 355 PM UNTIL
1100 PM CDT.

TORNADOES...HAIL TO 2 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 90 STATUTE
MILES EITHER SIDE OF A LINE FROM 45 MILES NORTHWEST OF PORT
ARTHUR TEXAS TO 40 MILES SOUTH SOUTHEAST OF ALEXANDRIA 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 70...

DISCUSSION...THUNDERSTORM ARE SLOWLY INCREASING IN COVERAGE AND
INTENSITY OVER PARTS OF SERN TX...AND ACTIVITY IS EXPECTED TO SPREAD
EWD/NEWD THIS EVENING IN LEFT EXIT REGION OF STRONG UPPER LEVEL JET.
 AIR MASS HAS RECOVERED IN THE WAKE OF EARLIER OUTFLOW
BOUNDARY...WITH SURFACE DEW POINTS IN UPPER 60S AND TEMPERATURES
75-80F.  THIS IS CONTRIBUTING TO UNSTABLE ENVIRONMENT WITH MLCAPE OF
2000-2500 J/KG.  STRONG DEEP LAYER SHEAR OF 45-55 KT WILL SUPPORT
SUPERCELL DEVELOPMENT WITH POTENTIAL FOR LARGE HAIL AND DAMAGING
WIND GUSTS.  IN ADDITION...SUFFICIENT LOW LEVEL SHEAR AND HELICITY
ARE EVIDENT IN LCH 18Z RAOB AND LATEST LCH VWP SUGGESTING POTENTIAL
FOR A FEW TORNADOES.

AVIATION...TORNADOES AND 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
550. MEAN STORM MOTION VECTOR 24030.


...WEISS

Tornado Watches in Louisiana, 2009Tornado Watches in Texas, 2009Every tornado watch in 2009

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.