Alert archive / Texas / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 83
The Storm Prediction Center issued this severe thunderstorm watch at Apr 9, 2021, 5:32 PM CDT for 17 parishes in Louisiana; 22 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 9, 2021, 5:32 PM CDT (22:32 UTC)
- Expired
- Apr 10, 2021, 1:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 65 kt
All 39 counties
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, Brazos County, TX, Burleson County, TX, Cherokee County, TX, Gregg County, TX, Grimes County, TX, Harrison County, TX, Houston County, TX, Madison County, TX, Marion County, TX, Nacogdoches County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Smith County, TX, Trinity County, TX, Walker County, TX, Washington County, TX
The radar
The Ft Polk radar (KPOE), 93 km from the middle of the area, began a volume at 22:33 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
- 10%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
29 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 5:38 PM CDT | Severe Thunderstorm Warning | SHV | Bossier, Claiborne, Webster | 67 min |
| Apr 9, 5:44 PM CDT | Severe Thunderstorm Warning | SHV | Ouachita, Union | 46 min |
| Apr 9, 5:49 PM CDT | Severe Thunderstorm Warning | SHV | De Soto | 56 min |
| Apr 9, 5:54 PM CDT | Severe Thunderstorm Warning | SHV | Caldwell, Jackson, Ouachita, Winn | 66 min |
| Apr 9, 5:57 PM CDT | Severe Thunderstorm Warning | HGX | Houston, Trinity | 33 min |
| Apr 9, 5:58 PM CDT | Severe Thunderstorm Warning | SHV | Union | 21 min |
| Apr 9, 6:01 PM CDT | Severe Thunderstorm Warning | SHV | Panola, Rusk, Shelby | 59 min |
| Apr 9, 6:23 PM CDT | Severe Thunderstorm Warning | SHV | Bienville, Jackson, Lincoln, Natchitoches, Red River, Winn | 52 min |
| Apr 9, 6:33 PM CDT | Flash Flood Warning | SHV | Cherokee, Nacogdoches, Panola, Rusk, Smith | 3 hr |
| Apr 9, 6:40 PM CDT | Severe Thunderstorm Warning | SHV | Bienville, Claiborne, Lincoln, Union | 65 min |
| Apr 9, 6:49 PM CDT | Severe Thunderstorm Warning | SHV | Bienville, Caddo, De Soto, Red River | 56 min |
| Apr 9, 6:53 PM CDT | Severe Thunderstorm Warning | SHV | Panola, Rusk | 45 min |
| Apr 9, 6:55 PM CDT | Severe Thunderstorm Warning | SHV | Ouachita, Union | 65 min |
| Apr 9, 7:11 PM CDT | Severe Thunderstorm Warning | SHV | De Soto, Natchitoches, Red River, Sabine | 64 min |
| Apr 9, 7:11 PM CDT | Severe Thunderstorm Warning | SHV | Gregg, Harrison, Rusk | 27 min |
| Apr 9, 7:18 PM CDT | Severe Thunderstorm Warning | SHV | Caldwell, Jackson, Ouachita | 42 min |
| Apr 9, 7:35 PM CDT | Flash Flood Warning | SHV | Caldwell, Jackson, Lincoln, Ouachita, Union, Winn | 3 hr |
| Apr 9, 7:40 PM CDT | Severe Thunderstorm Warning | SHV | Bienville, Natchitoches, Red River, Winn | 42 min |
| Apr 9, 7:55 PM CDT | Severe Thunderstorm Warning | SHV | Bienville, Grant, Jackson, Natchitoches, Winn | 65 min |
| Apr 9, 7:57 PM CDT | Severe Thunderstorm Warning | SHV | Caldwell, Ouachita | 22 min |
| Apr 9, 8:08 PM CDT | Severe Thunderstorm Warning | SHV | Angelina, Nacogdoches, San Augustine | 42 min |
| Apr 9, 8:43 PM CDT | Severe Thunderstorm Warning | SHV | Caldwell, Ouachita, Winn | 62 min |
| Apr 9, 10:02 PM CDT | Severe Thunderstorm Warning | SHV | Cherokee, Nacogdoches, Rusk | 58 min |
| Apr 9, 10:27 PM CDT | Severe Thunderstorm Warning | SHV | Grant, LaSalle | 40 min |
| Apr 9, 10:29 PM CDT | Severe Thunderstorm Warning | HGX | Houston | 46 min |
| Apr 9, 10:50 PM CDT | Severe Thunderstorm Warning | SHV | Nacogdoches, Rusk, San Augustine, Shelby | 55 min |
| Apr 9, 11:42 PM CDT | Severe Thunderstorm Warning | SHV | Caddo | 63 min |
| Apr 9, 11:47 PM CDT | Severe Thunderstorm Warning | SHV | Camp, Franklin, Gregg, Smith, Upshur, Wood | 43 min |
| Apr 10, 12:45 AM CDT | Severe Thunderstorm Warning | SHV | LaSalle | 45 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 12:00Z, 10.5 hours before the alert went out and 110 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
- 928 J/kg
- Mixed-layer CIN
- -310 J/kg
- Mixed-layer LCL
- 1043 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 6 m²/s²
- 0-3 km storm-relative helicity
- 61 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
735
WWUS20 KWNS 092229
SEL3
SPC WW 092229
LAZ000-TXZ000-100400-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 83
NWS Storm Prediction Center Norman OK
530 PM CDT Fri Apr 9 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northern Louisiana
East Texas
* Effective this Friday afternoon and evening from 530 PM until
1100 PM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
A tornado or two possible
SUMMARY...Multiple clusters along modifying outflow will pose a risk
for mainly large hail and locally damaging winds. Convection may
grow upscale into an MCS towards late evening with an increasing
severe threat.
The severe thunderstorm watch area is approximately along and 40
statute miles north and south of a line from 15 miles south of
Monroe LA to 15 miles west of College Station TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 76...WW 77...WW 78...WW
79...WW 80...WW 81...WW 82...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27025.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 2:49 AM CDT | Mesoscale Discussion | SPC | Jefferson, Plaquemines, Saint Bernard | 2 hr |
| Apr 9, 9:49 AM CDT | Mesoscale Discussion | SPC | Bossier, Caddo | 116 min |
| Apr 9, 12:07 PM CDT | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more | 6 hr |
| Apr 9, 1:25 PM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caldwell, Claiborne, De Soto, East Carroll and 12 more | 95 min |
| Apr 9, 3:10 PM CDT | Mesoscale Discussion | SPC | Claiborne, East Carroll, Lincoln, Morehouse, Ouachita, Richland and 2 more | 95 min |
| Apr 9, 3:42 PM CDT | Severe Thunderstorm Watch | SPC | East Carroll, Franklin, Madison, Morehouse, Richland, Tensas and 1 more | 7 hr |
| Apr 9, 5:19 PM CDT | Mesoscale Discussion | SPC | Bienville, Caldwell, Claiborne, De Soto, Franklin, Grant and 10 more | 116 min |
| Apr 9, 6:14 PM CDT | Mesoscale Discussion | SPC | Caldwell, East Carroll, Franklin, Madison, Morehouse, Ouachita and 2 more | 3 hr |
| Apr 8, 9:58 PM CDT | Mesoscale Discussion | SPC | Anderson, Brazos, Cherokee, Freestone, Grimes, Henderson and 7 more | 2 hr |
| Apr 9, 3:14 PM CDT | Mesoscale Discussion | SPC | Cooke, Delta, Fannin, Grayson, Lamar, Montague and 1 more | 61 min |
| Apr 9, 3:59 PM CDT | Mesoscale Discussion | SPC | Bastrop, Bell, Blanco, Bosque, Burnet, Caldwell and 14 more | 2 hr |
| Apr 9, 4:27 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bell, Bosque, Collin, Cooke, Coryell and 26 more | 9 hr |
Nearby
Severe Thunderstorm Watches in Texas, 2021Severe Thunderstorm Watches in Louisiana, 2021Every severe thunderstorm 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.