Alert archive / Texas / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 162
The Storm Prediction Center issued this severe thunderstorm watch at Apr 19, 2011, 11:45 PM CDT for 7 counties in Arkansas; 6 parishes in Louisiana; 12 counties in Texas. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 19, 2011, 11:45 PM CDT (04:45 UTC)
- Expired
- Apr 20, 2011, 3:02 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 25 counties
Columbia County, AR, Hempstead County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Union County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Lincoln Parish, LA, Union Parish, LA, Webster 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, Red River County, TX, Titus County, TX, Upshur County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 85 km from the middle of the area, began a volume at 04:46 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 12:09 AM CDT | Severe Thunderstorm Warning | SHV | Hempstead, Lafayette, Miller | 33 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, 4.8 hours before the alert went out and 86 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.
- Mixed-layer CAPE
- 2277 J/kg
- Mixed-layer CIN
- -179 J/kg
- Mixed-layer LCL
- 1895 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 127 m²/s²
- 0-3 km storm-relative helicity
- 165 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 4.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 7:47 PM CDT | Mesoscale Discussion | SPC | Conway, Franklin, Howard, Johnson, Little River, Logan and 13 more | 88 min |
| Apr 19, 8:07 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clay, Cleveland, Craighead, Crittenden, Cross and 18 more | 83 min |
| Apr 19, 10:14 PM CDT | Tornado Watch | SPC | Ashley, Chicot | 7 hr |
| Apr 19, 11:17 PM CDT | Mesoscale Discussion | SPC | Columbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more | 58 min |
| Apr 20, 3:37 AM CDT | Severe Thunderstorm Watch | SPC | Ashley, Chicot | 8 hr |
| Apr 20, 12:46 PM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Columbia, Desha and 8 more | 89 min |
| Apr 20, 1:02 PM CDT | Severe Thunderstorm Watch | SPC | Ashley, Chicot, Lee, Phillips | 7 hr |
| Apr 20, 2:04 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleburne, Cleveland and 36 more | 7 hr |
| Apr 20, 5:24 PM CDT | Mesoscale Discussion | SPC | Chicot, Drew | 96 min |
| Apr 20, 5:56 PM CDT | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Dallas and 23 more | 2 hr |
| Apr 19, 9:03 PM CDT | Mesoscale Discussion | SPC | Bell, Coryell, Falls, Freestone, Henderson, Hill and 3 more | 57 min |
| Apr 20, 1:52 PM CDT | Mesoscale Discussion | SPC | Bell, Bosque, Brown, Burnet, Coleman, Comanche and 21 more | 53 min |
| Apr 20, 2:21 PM CDT | Severe Thunderstorm Watch | SPC | Bandera, Bell, Blanco, Burnet, Concho, Coryell and 20 more | 8 hr |
| Apr 20, 5:47 PM CDT | Mesoscale Discussion | SPC | Blanco, Burnet, Concho, Crockett, Edwards, Gillespie and 15 more | 58 min |
Nearby
Severe Thunderstorm Watches in Texas, 2011Severe Thunderstorm Watches in Arkansas, 2011Severe Thunderstorm Watches in Louisiana, 2011Every severe thunderstorm 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; radar from the NEXRAD Level II archive.