Alert archive / Texas / Mesoscale Discussions in 2020

Mesoscale Discussion 405

April 19, 2020Beauregard Parish, Calcasieu Parish, Vernon Parish, Louisiana; 17 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2020, 12:39 PM CDT for Beauregard Parish, Calcasieu Parish, Vernon Parish, Louisiana; 17 counties in Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Apr 19, 2020, 12:39 PM CDT (17:39 UTC)
Expired: Apr 19, 2020, 1:45 PM CDT
In force: 66 min
Issued by: the Storm Prediction Center

Counties Beauregard Parish, LA, Calcasieu Parish, LA, Vernon Parish, LA, Brazoria County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Jacinto County, TX, Tyler County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 88 km from the middle of the area, began a volume at 17:39 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 122Apr 19, 2:40 PM CDT

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 5.7 hours before the alert went out and 136 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: 1153 J/kg
Mixed-layer CIN: -291 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 276 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.7

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
Apr 18, 8:27 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more	2 hr
Apr 18, 8:56 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Cameron, East Baton Rouge and 26 more	2 hr
Apr 19, 8:41 AM CDT	Tornado Watch	SPC	Allen, Beauregard, Bienville, Bossier, Caddo, Calcasieu and 18 more	6 hr
Apr 19, 10:45 AM CDT	Mesoscale Discussion	SPC	Caldwell, De Soto, Grant, Jackson, LaSalle, Natchitoches and 5 more	2 hr
Apr 19, 11:06 AM CDT	Mesoscale Discussion	SPC	Avoyelles, Catahoula, Concordia, Franklin, Madison, Richland and 1 more	54 min
Apr 19, 11:45 AM CDT	Tornado Watch	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more	9 hr
Apr 19, 12:47 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Bienville, Caldwell, Catahoula, Concordia, De Soto and 14 more	58 min
Apr 19, 2:03 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Assumption, Avoyelles, Beauregard, Calcasieu and 23 more	57 min
Apr 19, 2:39 PM CDT	Tornado Watch	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 39 more	9 hr
Apr 19, 3:07 PM CDT	Mesoscale Discussion	SPC	Madison, Tensas	113 min
Apr 19, 5:40 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 18 more	2 hr
Apr 19, 6:37 PM CDT	Mesoscale Discussion	SPC	Washington	53 min
Apr 19, 7:22 AM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Austin, Bastrop, Bell, Brazoria and 52 more	113 min
Apr 19, 11:19 AM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Collin, Dallas, Delta and 16 more	116 min

Nearby

Mesoscale Discussions in Texas, 2020 Mesoscale Discussions in Louisiana, 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.