Alert archive / Louisiana / Tornado Watches in 2020
Tornado Watch 107
The Storm Prediction Center issued this tornado watch at Apr 12, 2020, 1:24 PM CDT for 22 parishes in Louisiana; 17 counties in Mississippi. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2020, 1:24 PM CDT (18:24 UTC)
- Expired
- Apr 12, 2020, 10:23 PM CDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 39 counties
Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Pike County, MS, Walthall 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
- 50%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 3:14 PM CDT | Severe Thunderstorm Warning | LIX | Amite, Pike | 23 min |
| Apr 12, 3:23 PM CDT | Tornado Warning | LIX | Pike | 14 min |
| Apr 12, 3:28 PM CDT | Tornado Warning | LIX | Walthall | 32 min |
| Apr 12, 3:39 PM CDT | Tornado Warning | JAN | Covington, Jefferson Davis, Lamar, Lawrence, Marion | 66 min |
| Apr 12, 3:43 PM CDT | Severe Thunderstorm Warning | LIX | Saint Helena, Tangipahoa | 44 min |
| Apr 12, 3:48 PM CDT | Tornado Warning | LIX | Amite, Pike, Walthall | 27 min |
| Apr 12, 4:14 PM CDT | Tornado Warning | LIX | Pike, Walthall | 26 min |
| Apr 12, 4:28 PM CDT | Tornado Warning | JAN | Jefferson Davis, Lawrence, Marion | 47 min |
| Apr 12, 4:28 PM CDT | Tornado Warning | JAN | Jasper, Jones | 62 min |
| Apr 12, 5:01 PM CDT | Tornado Warning | JAN | Covington, Jasper, Jones, Smith | 59 min |
| Apr 12, 5:05 PM CDT | Severe Thunderstorm Warning | LIX | Ascension, Assumption, Livingston, Saint James, Saint John the Baptist | 25 min |
| Apr 12, 5:37 PM CDT | Severe Thunderstorm Warning | LIX | Saint Tammany, Tangipahoa, Washington | 68 min |
| Apr 12, 7:02 PM CDT | Severe Thunderstorm Warning | LIX | Livingston, Tangipahoa | 43 min |
| Apr 12, 8:20 PM CDT | Severe Thunderstorm Warning | JAN | Forrest, Lamar | 25 min |
| Apr 12, 8:40 PM CDT | Severe Thunderstorm Warning | LIX | Amite, Wilkinson | 33 min |
| Apr 12, 9:08 PM CDT | Severe Thunderstorm Warning | LIX | Saint Tammany | 31 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
Slidell Radar S, LA (KSIL), launched 12:00Z, 6.4 hours before the alert went out and 153 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
- 1968 J/kg
- Mixed-layer CIN
- -74 J/kg
- Mixed-layer LCL
- 480 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 302 m²/s²
- 0-3 km storm-relative helicity
- 580 m²/s²
- Significant tornado parameter
- 2.7
- Supercell composite
- 9.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 5:52 AM CDT | Tornado Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more | 8 hr |
| Apr 12, 7:18 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more | 87 min |
| Apr 12, 9:30 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more | 90 min |
| Apr 12, 10:24 AM CDT | Mesoscale Discussion | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more | 96 min |
| Apr 12, 10:41 AM CDT | Tornado Watch | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more | 10 hr |
| Apr 12, 12:03 PM CDT | Mesoscale Discussion | SPC | East Carroll, Franklin, Madison, Morehouse, Richland, West Carroll | 87 min |
| Apr 12, 1:02 PM CDT | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 12 more | 118 min |
| Apr 12, 5:27 PM CDT | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 6 more | 63 min |
| Apr 12, 5:44 PM CDT | Mesoscale Discussion | SPC | Madison, Tensas | 91 min |
| Apr 12, 5:59 PM CDT | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, Jackson and 5 more | 4 hr |
| Apr 12, 6:14 PM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Claiborne, Lincoln, Red River and 1 more | 91 min |
| Apr 12, 1:40 PM CDT | Mesoscale Discussion | SPC | Attala, Choctaw, Hinds, Holmes, Kemper, Lauderdale and 10 more | 95 min |
| Apr 12, 3:38 PM CDT | Mesoscale Discussion | SPC | Copiah, Covington, Jasper, Jefferson Davis, Kemper, Lauderdale and 14 more | 97 min |
| Apr 12, 3:52 PM CDT | Mesoscale Discussion | SPC | Covington, Jefferson Davis, Jones, Marion | 23 min |
| Apr 12, 3:53 PM CDT | Mesoscale Discussion | SPC | Greene, Perry, Wayne | 97 min |
| Apr 12, 4:26 PM CDT | Mesoscale Discussion | SPC | Covington, Jasper, Jones | 34 min |
| Apr 12, 4:38 PM CDT | Tornado Watch | SPC | George, Greene, Perry, Stone, Wayne | 7 hr |
| Apr 12, 4:54 PM CDT | Mesoscale Discussion | SPC | Clarke, Covington, Jasper, Jefferson Davis, Jones, Wayne | 66 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.