Alert archive / Louisiana / Mesoscale Discussions in 2020

Mesoscale Discussion 154

March 4, 202030 parishes in Louisiana; 23 counties in Mississippi; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 4, 2020, 10:50 AM CST for 30 parishes in Louisiana; 23 counties in Mississippi; 11 counties in Texas. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Mar 4, 2020, 10:50 AM CST (16:50 UTC)
Expired: Mar 4, 2020, 12:45 PM CST
In force: 115 min
Issued by: the Storm Prediction Center

All 64 counties

Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Natchitoches Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Vernon Parish, LA, Washington Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Angelina County, TX, Houston County, TX, Jasper County, TX, Nacogdoches County, TX, Newton County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX

The radar

The Ft Polk radar (KPOE), 61 km from the middle of the area, began a volume at 16:51 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.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 4.8 hours before the alert went out and 161 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1481 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 488 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 294 m²/s²
Significant tornado parameter: 2.5
Supercell composite: 10.5

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.

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, 5:02 AM CST	Severe Thunderstorm Watch	SPC	Allen, Avoyelles, Beauregard, Bienville, Caldwell, De Soto and 12 more	7 hr
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

Mesoscale Discussions in Louisiana, 2020 Mesoscale Discussions in Mississippi, 2020 Mesoscale Discussions in Texas, 2020 Every 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; radar from the NEXRAD Level II archive.