Alert archive / Louisiana / Tornado Watches in 2008

Tornado Watch 133

March 18, 2008Union County, Arkansas; 33 parishes in Louisiana; 18 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 18, 2008, 6:47 PM CDT for Union County, Arkansas; 33 parishes in Louisiana; 18 counties in Texas. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Mar 18, 2008, 6:47 PM CDT (23:47 UTC)
Expired
Mar 19, 2008, 4:00 AM CDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 52 counties

Union County, AR, Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Iberia Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Union Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Anderson County, TX, Angelina County, TX, Chambers County, TX, Cherokee County, TX, Galveston County, TX, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, Shelby 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
80%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 18, 7:49 PM CDTSevere Thunderstorm WarningSHVCherokee, Rusk, Smith41 min
Mar 18, 9:17 PM CDTSevere Thunderstorm WarningSHVHarrison, Panola, Rusk43 min
Mar 18, 10:19 PM CDTSevere Thunderstorm WarningSHVCaddo41 min
Mar 18, 11:52 PM CDTTornado WarningLCHAvoyelles, Saint Landry23 min
Mar 19, 12:13 AM CDTTornado WarningLCHAvoyelles32 min
Mar 19, 12:30 AM CDTSevere Thunderstorm WarningLCHLafayette, Saint Landry, Saint Martin, Vermilion30 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 12:00Z, 11.8 hours before the alert went out and 147 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 12:00Z on 2008-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 650 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2008-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 463 square meters per square second.1939587897Sfc1 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
650 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
701 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
463 m²/s²
0-3 km storm-relative helicity
536 m²/s²
Significant tornado parameter
0.7
Supercell composite
7.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 17, 7:34 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 11 more56 min
Mar 17, 9:36 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 20 more114 min
Mar 17, 10:16 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 31 more8 hr
Mar 18, 1:13 AM CDTMesoscale DiscussionSPCWashington62 min
Mar 18, 2:23 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Fulton, Madison and 2 more2 hr
Mar 18, 2:46 AM CDTMesoscale DiscussionSPCBaxter, Cleburne, Conway, Crawford, Faulkner, Franklin and 27 more89 min
Mar 18, 5:54 AM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Madison, Washington2 hr
Mar 18, 9:26 AM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Conway, Dallas, Garland and 19 more2 hr
Mar 18, 10:16 AM CDTTornado Watch PDSSPCArkansas, Clark, Clay, Cleburne, Cleveland, Columbia and 48 more7 hr
Mar 18, 10:59 AM CDTTornado Watch PDSSPCUnion8 hr
Mar 18, 11:54 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 6 more3 hr
Mar 18, 12:10 PM CDTMesoscale DiscussionSPCArkansas, Clark, Cleburne, Cleveland, Conway, Craighead and 47 more2 hr
Mar 18, 1:51 PM CDTMesoscale DiscussionSPCPolk, Sevier3 hr
Mar 18, 3:54 PM CDTMesoscale DiscussionSPCClark, Cleburne, Columbia, Dallas, Faulkner, Garland and 21 more2 hr
Mar 18, 4:46 PM CDTMesoscale DiscussionSPCArkansas, Clark, Clay, Craighead, Crittenden, Cross and 19 more59 min
Mar 18, 5:19 PM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 43 more11 hr
Mar 18, 6:06 PM CDTMesoscale DiscussionSPCClark, Clay, Cleburne, Conway, Craighead, Cross and 20 more3 hr
Mar 18, 6:19 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 22 more56 min
Mar 17, 7:09 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Wichita, Wilbarger7 hr
Mar 17, 9:17 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 53 more58 min
Mar 17, 10:21 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Wichita, Wilbarger54 min
Mar 17, 11:06 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 53 more54 min
Mar 18, 1:32 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 9 more58 min
Mar 18, 1:43 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 9 more32 min
Mar 18, 1:52 AM CDTTornado WatchSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 34 more7 hr
Mar 18, 4:57 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Coryell, Gillespie, Hamilton and 7 more93 min
Mar 18, 7:22 AM CDTMesoscale DiscussionSPCAnderson, Austin, Bastrop, Bell, Brazoria, Brazos and 40 more113 min
Mar 18, 7:50 AM CDTMesoscale DiscussionSPCBandera, Bosque, Brown, Burnet, Coleman, Comanche and 19 more55 min
Mar 18, 1:19 PM CDTMesoscale DiscussionSPCAnderson, Austin, Bastrop, Bell, Brazos, Burleson and 37 more116 min

Nearby

Tornado Watches in Louisiana, 2008Tornado Watches in Texas, 2008Tornado Watches in Arkansas, 2008Every tornado watch in 2008

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.