Alert archive / Louisiana / Tornado Watches in 2010

Tornado Watch 79

April 23, 201021 counties in Arkansas; 26 parishes in Louisiana; 16 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 23, 2010, 9:53 AM CDT for 21 counties in Arkansas; 26 parishes in Louisiana; 16 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 23, 2010, 9:53 AM CDT (14:53 UTC)
Expired
Apr 23, 2010, 5:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 63 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 79 km from the middle of the area, began a volume at 14:57 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

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

Two or more tornadoes
60%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 23, 11:15 AM CDTSevere Thunderstorm WarningSHVJackson, Lincoln, Ouachita17 min
Apr 23, 12:08 PM CDTSevere Thunderstorm WarningJANMadison, Tensas52 min
Apr 23, 12:27 PM CDTSevere Thunderstorm WarningSHVOuachita29 min
Apr 23, 12:29 PM CDTSevere Thunderstorm WarningSHVClaiborne, Webster46 min
Apr 23, 12:31 PM CDTSevere Thunderstorm WarningJANMadison, Tensas44 min
Apr 23, 12:52 PM CDTSevere Thunderstorm WarningSHVColumbia, Union53 min
Apr 23, 1:13 PM CDTSevere Thunderstorm WarningLZKMontgomery, Pike, Polk34 min
Apr 23, 1:21 PM CDTSevere Thunderstorm WarningLZKClark, Garland, Hot Spring, Montgomery, Pike24 min
Apr 23, 1:37 PM CDTSevere Thunderstorm WarningLZKBradley, Calhoun, Ouachita38 min
Apr 23, 2:09 PM CDTSevere Thunderstorm WarningLZKClark, Garland, Hot Spring, Saline51 min
Apr 23, 3:48 PM CDTSevere Thunderstorm WarningLZKCalhoun, Cleveland, Dallas, Grant, Jefferson, Ouachita42 min
Apr 23, 4:29 PM CDTSevere Thunderstorm WarningLZKCleveland, Dallas, Grant, Jefferson, Lincoln46 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

Jackson, MS (KJAN), launched 12:00Z, 2.9 hours before the alert went out and 329 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, Jackson, MS at 12:00Z on 2010-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 37 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, Jackson, MS at 12:00Z on 2010-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 square meters per square second.19395878Sfc1 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
37 J/kg
Mixed-layer CIN
-425 J/kg
Mixed-layer LCL
519 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 23, 8:28 AM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Clark, Columbia, Hempstead and 9 more62 min
Apr 23, 12:08 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 14 more67 min
Apr 23, 12:51 PM CDTTornado WatchSPCArkansas, Clay, Cleburne, Conway, Craighead, Crittenden and 28 more9 hr
Apr 23, 2:50 PM CDTMesoscale DiscussionSPCClark, Columbia, Garland, Hempstead, Hot Spring, Howard and 9 more115 min
Apr 23, 3:47 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Clay, Cleburne, Conway, Craighead and 29 more58 min
Apr 23, 5:24 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more36 min
Apr 23, 5:41 PM CDTTornado WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more9 hr
Apr 23, 6:31 PM CDTMesoscale DiscussionSPCArkansas, Clay, Cleburne, Cleveland, Conway, Craighead and 26 more29 min
Apr 23, 6:51 PM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 40 more8 hr
Apr 22, 7:45 PM CDTMesoscale DiscussionSPCBriscoe, Childress, Collingsworth, Cottle, Crosby, Dickens and 20 more60 min
Apr 22, 8:31 PM CDTTornado WatchSPCAndrews, Archer, Baylor, Borden, Briscoe, Childress and 35 more7 hr
Apr 22, 9:17 PM CDTMesoscale DiscussionSPCCoke, Concho, Crane, Crockett, Ector, Edwards and 16 more28 min
Apr 22, 9:32 PM CDTTornado WatchSPCCallahan, Coke, Coleman, Concho, Crane, Crockett and 20 more6 hr
Apr 23, 12:00 AM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Briscoe, Callahan, Childress and 53 more60 min
Apr 23, 2:01 AM CDTMesoscale DiscussionSPCArcher, Callahan, Clay, Coleman, Concho, Eastland and 8 more119 min

Nearby

Tornado Watches in Louisiana, 2010Tornado Watches in Arkansas, 2010Tornado Watches in Texas, 2010Every tornado watch in 2010

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; radar from the NEXRAD Level II archive.