Alert archive / Louisiana / Tornado Watches in 2020
Tornado Watch 494
The Storm Prediction Center issued this tornado watch at Sep 23, 2020, 2:37 PM CDT for 10 parishes in Louisiana; 8 counties in Mississippi. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 23, 2020, 2:37 PM CDT (19:37 UTC)
- Expired
- Sep 23, 2020, 10:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
Counties Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Copiah County, MS, Franklin County, MS, Jefferson County, MS, Lincoln County, MS, Pike County, MS, Wilkinson County, MS
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 30%
Warnings issued inside it
17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 23, 2:39 PM CDT | Flash Flood Warning | LCH | Avoyelles, Evangeline, Rapides | 96 min |
| Sep 23, 2:58 PM CDT | Tornado Warning | LCH | Avoyelles | 17 min |
| Sep 23, 3:00 PM CDT | Severe Thunderstorm Warning | JAN | Catahoula, Concordia | 60 min |
| Sep 23, 3:13 PM CDT | Tornado Warning | LIX | Wilkinson | 32 min |
| Sep 23, 3:14 PM CDT | Tornado Warning | JAN | Concordia | 61 min |
| Sep 23, 3:35 PM CDT | Tornado Warning | LIX | West Feliciana | 40 min |
| Sep 23, 3:52 PM CDT | Tornado Warning | LIX | Wilkinson | 23 min |
| Sep 23, 4:03 PM CDT | Flash Flood Warning | LCH | Allen, Avoyelles, Evangeline, Rapides, Vernon | 6 hr |
| Sep 23, 4:15 PM CDT | Severe Thunderstorm Warning | JAN | Adams, Franklin | 37 min |
| Sep 23, 4:18 PM CDT | Severe Thunderstorm Warning | LIX | Wilkinson | 38 min |
| Sep 23, 5:13 PM CDT | Severe Thunderstorm Warning | LIX | East Feliciana, West Feliciana | 47 min |
| Sep 23, 5:15 PM CDT | Tornado Warning | LIX | Wilkinson | 12 min |
| Sep 23, 5:23 PM CDT | Flash Flood Warning | JAN | Catahoula, Concordia, Tensas | 3 hr |
| Sep 23, 5:39 PM CDT | Severe Thunderstorm Warning | JAN | Adams, Franklin, Jefferson | 26 min |
| Sep 23, 7:37 PM CDT | Flash Flood Warning | JAN | Adams, Claiborne, Copiah, Franklin, Jefferson, Lincoln | 3 hr |
| Sep 23, 8:10 PM CDT | Flash Flood Warning | JAN | Claiborne, Copiah, Franklin, Jefferson, Lincoln | 3 hr |
| Sep 23, 8:36 PM CDT | Tornado Warning | JAN | Claiborne, Jefferson | 28 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
Jackson, MS (KJAN), launched 12:00Z, 7.6 hours before the alert went out and 171 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
- 729 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 134 m²/s²
- 0-3 km storm-relative helicity
- 148 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 |
|---|---|---|---|---|
| Sep 23, 1:14 PM CDT | Mesoscale Discussion | SPC | Allen, Ascension, Assumption, Avoyelles, Catahoula, Concordia and 19 more | 2 hr |
| Sep 23, 5:20 PM CDT | Mesoscale Discussion | SPC | Avoyelles, Concordia, East Feliciana, Pointe Coupee, Saint Landry, West Feliciana | 115 min |
Nearby
Tornado Watches in Louisiana, 2020Tornado Watches in Mississippi, 2020Every tornado 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.