Alert archive / Louisiana / Severe Thunderstorm Watches in 2020
Severe Thunderstorm Watch 42
The Storm Prediction Center issued this severe thunderstorm watch at Mar 4, 2020, 5:02 AM CST for 18 parishes in Louisiana; 11 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 4, 2020, 5:02 AM CST (11:02 UTC)
- Expired
- Mar 4, 2020, 12:00 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 29 counties
Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Ouachita 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, Cherokee County, TX, Jasper County, TX, Nacogdoches County, TX, Newton County, TX, Panola County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Tyler County, TX
The radar
The Ft Polk radar (KPOE), 33 km from the middle of the area, began a volume at 11:01 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
- 40%
- 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
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 4, 5:12 AM CST | Severe Thunderstorm Warning | SHV | Sabine | 48 min |
| Mar 4, 5:57 AM CST | Severe Thunderstorm Warning | SHV | Natchitoches, Sabine | 41 min |
| Mar 4, 6:44 AM CST | Severe Thunderstorm Warning | SHV | Cherokee, Rusk, Smith | 46 min |
| Mar 4, 6:48 AM CST | Severe Thunderstorm Warning | SHV | Harrison, Panola, Rusk | 42 min |
| Mar 4, 7:21 AM CST | Severe Thunderstorm Warning | SHV | Harrison, Panola, Rusk | 39 min |
| Mar 4, 7:24 AM CST | Severe Thunderstorm Warning | SHV | Cherokee, Rusk, Smith | 51 min |
| Mar 4, 7:26 AM CST | Severe Thunderstorm Warning | SHV | Caddo, De Soto | 49 min |
| Mar 4, 7:34 AM CST | Flash Flood Warning | SHV | Cherokee, Rusk, Smith | 3 hr |
| Mar 4, 7:52 AM CST | Severe Thunderstorm Warning | SHV | Caddo, De Soto | 27 min |
| Mar 4, 8:03 AM CST | Severe Thunderstorm Warning | SHV | Bienville, Bossier, Caddo, De Soto, Red River, Webster | 21 min |
| Mar 4, 8:44 AM CST | Flash Flood Warning | SHV | Bossier, Caddo, De Soto, Webster | 3 hr |
| Mar 4, 9:51 AM CST | Flash Flood Warning | SHV | Bossier, Caddo, De Soto, Red River | 4 hr |
| Mar 4, 11:12 AM CST | Flash Flood Warning | SHV | De Soto, Sabine | 3 hr |
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, 11.0 hours before the alert went out and 148 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1591 m above ground
- 0-6 km bulk shear
- 87 kt
- 0-1 km storm-relative helicity
- -20 m²/s²
- 0-3 km storm-relative helicity
- 221 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 4, 1:19 AM CST | Mesoscale Discussion | SPC | Avoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 24 more | 2 hr |
| Mar 4, 1:53 AM CST | Tornado Watch | SPC | Catahoula, Concordia, East Carroll, East Feliciana, Franklin, Madison and 9 more | 8 hr |
| Mar 4, 4:20 AM CST | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Caldwell, De Soto, Grant and 11 more | 115 min |
| Mar 4, 10:50 AM CST | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Bienville, Caldwell, Catahoula and 24 more | 115 min |
| Mar 4, 1:57 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, Iberia, Iberville, Jefferson and 17 more | 2 hr |
| Mar 4, 5:05 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 13 more | 2 hr |
| Mar 3, 9:05 PM CST | Mesoscale Discussion | SPC | Bandera, Bastrop, Bell, Blanco, Burleson, Burnet and 23 more | 2 hr |
| Mar 4, 2:03 AM CST | Mesoscale Discussion | SPC | Bandera, Edwards, Gillespie, Kendall, Kerr, Kimble and 11 more | 117 min |
| Mar 4, 2:28 AM CST | Severe Thunderstorm Watch | SPC | Bandera, Bexar, Blanco, Burnet, Comal, Edwards and 13 more | 6 hr |
| Mar 4, 7:33 AM CST | Severe Thunderstorm Watch | SPC | Anderson, Brazos, Burleson, Falls, Freestone, Grimes and 10 more | 4 hr |
Nearby
Severe Thunderstorm Watches in Louisiana, 2020Severe Thunderstorm Watches in Texas, 2020Every severe thunderstorm watch in 2020
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.