Alert archive / Louisiana / Mesoscale Discussions in 2020

Mesoscale Discussion 24

January 11, 202017 parishes in Louisiana; 16 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jan 11, 2020, 12:21 AM CST for 17 parishes in Louisiana; 16 counties in Texas. It was in force for 99 min.

The area

The outline as issued.

The facts

Issued: Jan 11, 2020, 12:21 AM CST (06:21 UTC)
Expired: Jan 11, 2020, 2:00 AM CST
In force: 99 min
Issued by: the Storm Prediction Center
Concerning: Tornado watch 6

All 33 counties

Acadia Parish, LA, Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Brazoria County, TX, Chambers County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Tyler County, TX

The radar

The Lake Charles radar (KLCH), 56 km from the middle of the area, began a volume at 06:21 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 watches that followed

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

Tornado Watch 8Jan 11, 12:30 AM CST

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 6.4 hours before the alert went out and 57 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: 2102 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 501 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 197 m²/s²
0-3 km storm-relative helicity: 232 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 9.2

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
Jan 10, 7:30 PM CST	Mesoscale Discussion	SPC	Bossier, Caddo, Webster	2 hr
Jan 10, 10:40 PM CST	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 2 more	2 hr
Jan 11, 12:28 AM CST	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 24 more	8 hr
Jan 11, 1:19 AM CST	Mesoscale Discussion	SPC	Bienville, Caldwell, Claiborne, De Soto, Jackson, Lincoln and 7 more	86 min
Jan 11, 2:22 AM CST	Mesoscale Discussion	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more	53 min
Jan 11, 2:37 AM CST	Tornado Watch	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more	8 hr
Jan 11, 4:31 AM CST	Mesoscale Discussion	SPC	Acadia, Ascension, Avoyelles, Caldwell, Catahoula, Concordia and 21 more	59 min
Jan 11, 5:18 AM CST	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more	7 hr
Jan 11, 7:39 AM CST	Mesoscale Discussion	SPC	Ascension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 8 more	96 min
Jan 10, 6:30 PM CST	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 16 more	2 hr
Jan 10, 8:49 PM CST	Mesoscale Discussion	SPC	Angelina, Austin, Brazoria, Brazos, Burleson, Chambers and 25 more	116 min
Jan 10, 9:09 PM CST	Tornado Watch	SPC	Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more	5 hr
Jan 11, 7:34 AM CST	Mesoscale Discussion	SPC	Cooke, Denton, Fannin, Grayson	116 min

Nearby

Mesoscale Discussions in Louisiana, 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.