Alert archive / Louisiana / Tornado Watches in 2020

Tornado Watch 11

January 11, 202022 parishes in Louisiana; 6 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jan 11, 2020, 5:18 AM CST for 22 parishes in Louisiana; 6 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jan 11, 2020, 5:18 AM CST (11:18 UTC)
Expired
Jan 11, 2020, 11:58 AM CST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 28 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Hancock 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
60%
One or more gusts of 65 knots or more
20%
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
70%

Warnings issued inside it

3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jan 11, 6:07 AM CSTSevere Thunderstorm WarningLIXIberville, Pointe Coupee, West Baton Rouge, West Feliciana38 min
Jan 11, 6:33 AM CSTSevere Thunderstorm WarningLIXPointe Coupee, West Feliciana27 min
Jan 11, 8:26 AM CSTSevere Thunderstorm WarningLIXLafourche, Saint Charles, Terrebonne34 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 00:00Z, 11.3 hours before the alert went out and 220 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.

Skew-T log-pSkew-T log-p diagram, Jackson, MS at 00:00Z on 2020-01-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 213 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 00:00Z on 2020-01-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 276 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
213 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
607 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
276 m²/s²
0-3 km storm-relative helicity
306 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 10, 7:30 PM CSTMesoscale DiscussionSPCBossier, Caddo, Webster2 hr
Jan 10, 10:40 PM CSTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 2 more2 hr
Jan 11, 12:21 AM CSTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 11 more99 min
Jan 11, 12:28 AM CSTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 24 more8 hr
Jan 11, 1:19 AM CSTMesoscale DiscussionSPCBienville, Caldwell, Claiborne, De Soto, Jackson, Lincoln and 7 more86 min
Jan 11, 2:22 AM CSTMesoscale DiscussionSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more53 min
Jan 11, 2:37 AM CSTTornado WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more8 hr
Jan 11, 4:31 AM CSTMesoscale DiscussionSPCAcadia, Ascension, Avoyelles, Caldwell, Catahoula, Concordia and 21 more59 min
Jan 11, 7:39 AM CSTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 8 more96 min
Jan 10, 11:58 PM CSTTornado WatchSPCBolivar, Coahoma, DeSoto, Leflore, Marshall, Panola and 6 more7 hr
Jan 11, 3:52 AM CSTMesoscale DiscussionSPCBenton, Bolivar, Coahoma, DeSoto, Grenada, Lafayette and 9 more83 min
Jan 11, 4:17 AM CSTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 8 more6 hr
Jan 11, 5:06 AM CSTMesoscale DiscussionSPCAlcorn, Benton, DeSoto, Lafayette, Lee, Marshall and 7 more54 min
Jan 11, 7:57 AM CSTTornado WatchSPCClarke, Clay, Covington, Forrest, George, Greene and 20 more9 hr
Jan 11, 9:54 AM CSTMesoscale DiscussionSPCClarke, Forrest, Greene, Jasper, Jones, Kemper and 10 more96 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.