Alert archive / Texas / Tornado Watches in 2010

Tornado Watch 89

April 24, 20109 counties in Arkansas; 17 parishes in Louisiana; 21 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 24, 2010, 1:50 AM CDT for 9 counties in Arkansas; 17 parishes in Louisiana; 21 counties in Texas. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Apr 24, 2010, 1:50 AM CDT (06:50 UTC)
Expired
Apr 24, 2010, 10:00 AM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
70 kt
All 47 counties

Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 53 km from the middle of the area, began a volume at 06:53 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
60%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 24, 1:57 AM CDTSevere Thunderstorm WarningSHVSmith, Wood63 min
Apr 24, 2:27 AM CDTTornado WarningSHVWood19 min
Apr 24, 2:41 AM CDTSevere Thunderstorm WarningSHVCamp, Franklin, Gregg, Morris, Titus, Upshur49 min
Apr 24, 3:14 AM CDTSevere Thunderstorm WarningSHVBowie, Cass, Harrison, Marion, Red River46 min
Apr 24, 3:55 AM CDTSevere Thunderstorm WarningSHVHempstead, Howard, Little River, Nevada, Sevier50 min
Apr 24, 5:25 AM CDTSevere Thunderstorm WarningSHVUnion50 min
Apr 24, 5:40 AM CDTSevere Thunderstorm WarningSHVBossier, Caddo, Webster35 min
Apr 24, 5:51 AM CDTTornado WarningSHVBossier, Claiborne, Webster39 min
Apr 24, 5:54 AM CDTSevere Thunderstorm WarningSHVBienville, Claiborne, Lincoln, Union51 min
Apr 24, 6:23 AM CDTTornado WarningSHVUnion52 min
Apr 24, 7:07 AM CDTSevere Thunderstorm WarningSHVUnion38 min
Apr 24, 7:12 AM CDTTornado WarningSHVUnion33 min
Apr 24, 7:23 AM CDTSevere Thunderstorm WarningSHVDe Soto, Natchitoches, Red River, Sabine52 min
Apr 24, 7:43 AM CDTSevere Thunderstorm WarningSHVNatchitoches, Sabine47 min
Apr 24, 8:01 AM CDTSevere Thunderstorm WarningSHVBienville, Jackson, Lincoln, Natchitoches, Red River, Winn44 min
Apr 24, 8:38 AM CDTSevere Thunderstorm WarningSHVGrant, Jackson, Natchitoches, Winn52 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

Shreveport, LA (KSHV), launched 00:00Z, 6.8 hours before the alert went out and 62 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, Shreveport, LA at 00:00Z on 2010-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2092 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, Shreveport, LA at 00:00Z on 2010-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 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
2092 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
810 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
1.6
Supercell composite
8.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 23, 11:40 PM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clay, Cleveland, Craighead and 25 more65 min
Apr 24, 1:20 AM CDTMesoscale DiscussionSPCColumbia, Lafayette25 min
Apr 24, 2:44 AM CDTMesoscale DiscussionSPCArkansas, Cleburne, Cleveland, Craighead, Crittenden, Cross and 24 more91 min
Apr 24, 3:02 AM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Dallas and 14 more8 hr
Apr 24, 5:01 AM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Columbia, Drew and 2 more89 min
Apr 24, 6:00 AM CDTTornado Watch PDSSPCAshley, Chicot, Clay, Craighead, Crittenden, Cross and 8 more6 hr
Apr 24, 7:25 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Cleveland, Drew, Jefferson and 3 more95 min
Apr 24, 9:31 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Chicot, Cleveland, Crittenden, Cross and 12 more59 min
Apr 24, 11:08 AM CDTMesoscale DiscussionSPCArkansas, Baxter, Clay, Cleburne, Conway, Craighead and 24 more67 min
Apr 24, 11:31 AM CDTTornado Watch PDSSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more8 hr
Apr 24, 1:52 PM CDTMesoscale DiscussionSPCBaxter, Boone, Marion53 min
Apr 24, 2:01 PM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Greene, Mississippi, Poinsett89 min
Apr 24, 6:15 AM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more7 hr
Apr 24, 10:28 AM CDTMesoscale DiscussionSPCAvoyelles, Catahoula, Concordia, East Baton Rouge, East Feliciana, Franklin and 10 more92 min
Apr 24, 12:47 PM CDTTornado WatchSPCAscension, Jefferson, Lafourche, Livingston, Orleans, Plaquemines and 8 more7 hr
Apr 23, 7:57 PM CDTMesoscale DiscussionSPCBandera, Bell, Bexar, Blanco, Bosque, Brown and 38 more63 min
Apr 23, 9:34 PM CDTTornado WatchSPCAtascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 39 more7 hr
Apr 23, 11:16 PM CDTSevere Thunderstorm WatchSPCBosque, Collin, Coryell, Dallas, Denton, Ellis and 12 more4 hr

Nearby

Tornado Watches in Texas, 2010Tornado Watches in Louisiana, 2010Tornado Watches in Arkansas, 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.