Alert archive / Louisiana / Tornado Watches in 2011

Tornado Watch 210

April 25, 20116 parishes in Louisiana; 4 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 25, 2011, 10:47 PM CDT for 6 parishes in Louisiana; 4 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 25, 2011, 10:47 PM CDT (03:47 UTC)
Expired
Apr 26, 2011, 4:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt

Counties Allen Parish, LA, Beauregard Parish, LA, Evangeline Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Hardin County, TX, Jasper County, TX, Newton County, TX, Tyler County, TX

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
30%
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
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 25, 11:20 PM CDTTornado WarningLCHJasper25 min
Apr 25, 11:28 PM CDTSevere Thunderstorm WarningLCHJasper, Newton, Tyler62 min
Apr 25, 11:43 PM CDTTornado WarningLCHJasper, Newton32 min
Apr 26, 12:14 AM CDTTornado WarningLCHVernon31 min
Apr 26, 12:35 AM CDTSevere Thunderstorm WarningLCHJasper, Tyler55 min
Apr 26, 12:43 AM CDTTornado WarningLCHVernon47 min
Apr 26, 1:13 AM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Tyler62 min
Apr 26, 1:21 AM CDTSevere Thunderstorm WarningLCHRapides, Vernon39 min
Apr 26, 2:06 AM CDTSevere Thunderstorm WarningLCHBeauregard, Calcasieu24 min
Apr 26, 2:17 AM CDTSevere Thunderstorm WarningLCHAllen, Avoyelles, Evangeline, Rapides, Saint Landry58 min
Apr 26, 2:23 AM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Tyler52 min
Apr 26, 2:35 AM CDTSevere Thunderstorm WarningLCHAllen, Beauregard, Calcasieu, Jefferson Davis55 min
Apr 26, 2:56 AM CDTTornado WarningLCHHardin34 min
Apr 26, 3:17 AM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Jefferson, Newton, Orange58 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 3.8 hours before the alert went out and 112 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2759 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 2011-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2759 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
581 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
1.5
Supercell composite
8.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

838 
WWUS20 KWNS 260342
SEL0
SPC WW 260342
LAZ000-TXZ000-260900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 210
NWS STORM PREDICTION CENTER NORMAN OK
1045 PM CDT MON APR 25 2011

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

       PARTS OF WESTERN AND SOUTHWEST LOUISIANA
       SMALL PART OF SOUTHEAST TEXAS

EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 1045 PM
UNTIL 400 AM CDT.

TORNADOES...HAIL TO 2.5 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 35 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 85 MILES WEST OF FORT POLK
LOUISIANA TO 55 MILES EAST SOUTHEAST OF FORT POLK LOUISIANA.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU0).

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 205...WW 206...WW 207...

DISCUSSION...LONG-LIVED SUPERCELL ECENTRAL TX WILL LIKELY CONTINUE
TO BE A THREAT FOR LARGE HAIL AND TORNADOS FOR A FEW MORE HOURS
GIVEN THE SHEAR AND INSTABILITY ENVIRONMENT ACROSS SWRN LA.  THUS
EXPECT THE COMPLEX TO MOVE ESEWD INTO WRN LA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 29025.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 7:34 PM CDTMesoscale DiscussionSPCBossier, Claiborne, Lincoln, Union, Webster116 min
Apr 25, 9:23 PM CDTTornado WatchSPCCaldwell, East Carroll, Franklin, Madison, Morehouse, Ouachita and 2 more7 hr
Apr 25, 9:37 PM CDTMesoscale DiscussionSPCDe Soto, Sabine83 min
Apr 25, 11:05 PM CDTMesoscale DiscussionSPCEast Carroll, Morehouse, West Carroll115 min
Apr 26, 1:34 AM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 1 more86 min
Apr 26, 1:52 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 7 more5 hr
Apr 26, 1:11 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more2 hr
Apr 26, 1:44 PM CDTTornado Watch PDSSPCBossier, Caddo, Claiborne, Union, Webster10 hr
Apr 26, 3:59 PM CDTMesoscale DiscussionSPCBossier, Caddo, Claiborne, Union, Webster91 min
Apr 26, 4:56 PM CDTTornado WatchSPCBeauregard, Bienville, Caldwell, De Soto, Grant, Jackson and 9 more5 hr
Apr 26, 6:43 PM CDTMesoscale DiscussionSPCBeauregard, Bienville, Bossier, Caddo, Caldwell, Claiborne and 13 more2 hr
Apr 26, 3:01 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bastrop, Bee, Bexar, Blanco and 22 more89 min
Apr 26, 3:15 PM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Clay, Collingsworth, Cottle and 16 more90 min
Apr 26, 3:43 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Foard, Hardeman, Knox and 2 more6 hr

Nearby

Tornado Watches in Louisiana, 2011Tornado Watches in Texas, 2011Every tornado watch in 2011

Sources

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.