Alert archive / Texas / Tornado Watches in 2021
Tornado Watch 99
The Storm Prediction Center issued this tornado watch at Apr 23, 2021, 2:00 PM CDT for 19 parishes in Louisiana; 28 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 23, 2021, 2:00 PM CDT (19:00 UTC)
- Expired
- Apr 23, 2021, 9:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 47 counties
Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Austin County, TX, Brazos County, TX, Burleson County, TX, Chambers County, TX, Cherokee County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Houston County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Madison County, TX, Montgomery County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX
The radar
The Houston radar (KHGX), 154 km from the middle of the area, began a volume at 19:03 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
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 23, 4:47 PM CDT | Severe Thunderstorm Warning | LCH | Jasper, Tyler | 28 min |
| Apr 23, 5:01 PM CDT | Severe Thunderstorm Warning | SHV | Angelina, Sabine, San Augustine | 44 min |
| Apr 23, 5:12 PM CDT | Severe Thunderstorm Warning | LCH | Jasper, Tyler | 63 min |
| Apr 23, 5:19 PM CDT | Severe Thunderstorm Warning | HGX | Montgomery, Walker | 26 min |
| Apr 23, 5:45 PM CDT | Tornado Warning | HGX | Liberty, Montgomery, San Jacinto | 30 min |
| Apr 23, 5:48 PM CDT | Severe Thunderstorm Warning | HGX | Montgomery, Polk, San Jacinto, Walker | 27 min |
| Apr 23, 6:08 PM CDT | Severe Thunderstorm Warning | LCH | Jasper, Newton | 67 min |
| Apr 23, 6:09 PM CDT | Tornado Warning | HGX | Liberty, Polk, San Jacinto | 36 min |
| Apr 23, 6:27 PM CDT | Severe Thunderstorm Warning | HGX | Liberty, Polk | 18 min |
| Apr 23, 6:42 PM CDT | Severe Thunderstorm Warning | LCH | Hardin, Jasper, Newton, Tyler | 63 min |
| Apr 23, 7:15 PM CDT | Severe Thunderstorm Warning | LCH | Vernon | 60 min |
| Apr 23, 7:30 PM CDT | Tornado Warning | LCH | Jasper, Newton, Tyler | 30 min |
| Apr 23, 7:35 PM CDT | Tornado Warning | LCH | Vernon | 25 min |
| Apr 23, 7:45 PM CDT | Severe Thunderstorm Warning | LCH | Beauregard | 22 min |
| Apr 23, 7:57 PM CDT | Tornado Warning | LCH | Beauregard | 33 min |
| Apr 23, 8:00 PM CDT | Severe Thunderstorm Warning | LCH | Rapides, Vernon | 60 min |
| Apr 23, 8:25 PM CDT | Severe Thunderstorm Warning | LCH | Avoyelles, Rapides | 1 min |
| Apr 23, 8:26 PM CDT | Tornado Warning | LCH | Rapides, Vernon | 34 min |
| Apr 23, 8:29 PM CDT | Tornado Warning | LCH | Beauregard | 31 min |
| Apr 23, 9:00 PM CDT | Severe Thunderstorm Warning | LCH | Avoyelles, Rapides | 60 min |
| Apr 23, 9:00 PM CDT | Severe Thunderstorm Warning | LCH | Allen, Beauregard, Evangeline, Rapides, Vernon | 14 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, 7.0 hours before the alert went out and 161 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
- 12 J/kg
- Mixed-layer CIN
- -108 J/kg
- Mixed-layer LCL
- 523 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 373 m²/s²
- 0-3 km storm-relative helicity
- 419 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
682
WWUS20 KWNS 231853
SEL9
SPC WW 231853
LAZ000-TXZ000-CWZ000-240200-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 99
NWS Storm Prediction Center Norman OK
155 PM CDT Fri Apr 23 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Central and Western Louisiana
Southeast Texas
Coastal Waters
* Effective this Friday afternoon and evening from 155 PM until
900 PM CDT.
* Primary threats include...
A few tornadoes possible
Scattered damaging wind gusts to 70 mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
SUMMARY...Thunderstorms will increase in coverage and intensity this
afternoon across the region. A few supercell storms are
expected,capable of damaging winds, tornadoes, and large hail.
The tornado watch area is approximately along and 65 statute miles
north and south of a line from 35 miles south southwest of College
Station TX to 30 miles east of Alexandria LA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 98...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 25035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 23, 12:43 PM CDT | Mesoscale Discussion | SPC | Allen, Beauregard, Calcasieu, Cameron, De Soto, Jefferson Davis and 3 more | 2 hr |
| Apr 23, 5:36 PM CDT | Mesoscale Discussion | SPC | Allen, Avoyelles, Catahoula, Concordia, De Soto, East Feliciana and 12 more | 54 min |
| Apr 23, 11:29 AM CDT | Mesoscale Discussion | SPC | Archer, Bastrop, Bell, Bexar, Blanco, Bosque and 52 more | 91 min |
| Apr 23, 12:37 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Archer, Bastrop, Bell, Blanco, Bosque and 53 more | 7 hr |
| Apr 23, 12:43 PM CDT | Mesoscale Discussion | SPC | Baylor, Childress, Collingsworth, Cottle, Foard, Hall and 2 more | 3 hr |
| Apr 23, 3:14 PM CDT | Tornado Watch | SPC | Archer, Baylor, Childress, Clay, Collingsworth, Cottle and 7 more | 5 hr |
| Apr 23, 3:27 PM CDT | Mesoscale Discussion | SPC | Baylor, Foard, Hardeman, Wilbarger | 2 hr |
| Apr 23, 3:28 PM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Comanche, Eastland, Erath, Hamilton and 11 more | 2 hr |
| Apr 23, 5:26 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Clay, Foard, Hardeman, Knox and 2 more | 2 hr |
| Apr 23, 6:46 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bell, Bexar, Blanco, Bosque, Burnet and 19 more | 89 min |
Nearby
Tornado Watches in Texas, 2021Tornado Watches in Louisiana, 2021Every tornado watch in 2021
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.