Alert archive / Louisiana / Mesoscale Discussions in 2020

Mesoscale Discussion 28

January 11, 202027 parishes in Louisiana; 17 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 11, 2020, 4:31 AM CST for 27 parishes in Louisiana; 17 counties in Mississippi. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Jan 11, 2020, 4:31 AM CST (10:31 UTC)
Expired
Jan 11, 2020, 5:30 AM CST
In force
59 min
Issued by
the Storm Prediction Center
All 44 counties

Acadia Parish, LA, Ascension Parish, LA, Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Richland Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Tensas Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lincoln County, MS, Madison County, MS, Sharkey County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 10.5 hours before the alert went out and 154 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

The text

As transmitted.

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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, 5:18 AM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more7 hr
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

Mesoscale Discussions in Louisiana, 2020Mesoscale Discussions in Mississippi, 2020Every mesoscale discussion 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.