Alert archive / Texas / Mesoscale Discussions in 2019

Mesoscale Discussion 438

April 24, 20194 parishes in Louisiana; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2019, 11:19 PM CDT for 4 parishes in Louisiana; 5 counties in Texas. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Apr 24, 2019, 11:19 PM CDT (04:19 UTC)
Expired: Apr 25, 2019, 12:45 AM CDT
In force: 86 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Beauregard Parish, LA, Natchitoches Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Jasper County, TX, Newton County, TX, Orange County, TX, Sabine County, TX, San Augustine County, TX

The radar

The Ft Polk radar (KPOE), 80 km from the middle of the area, began a volume at 04:22 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 100Apr 24, 11:55 PM CDT

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 4.3 hours before the alert went out and 96 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: 369 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 768 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 92 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 0.9

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 24, 7:35 PM CDT	Mesoscale Discussion	SPC	Vernon	85 min
Apr 24, 11:52 PM CDT	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 19 more	8 hr
Apr 24, 11:57 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Claiborne, De Soto, Natchitoches, Red River and 2 more	63 min
Apr 25, 2:08 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 24 more	67 min
Apr 25, 2:43 AM CDT	Severe Thunderstorm Watch	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more	6 hr
Apr 25, 5:02 AM CDT	Mesoscale Discussion	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more	58 min
Apr 25, 5:24 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Beauregard, Calcasieu, Evangeline, Grant and 7 more	66 min
Apr 25, 7:10 AM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia and 22 more	2 hr
Apr 25, 8:06 AM CDT	Tornado Watch	SPC	Acadia, Ascension, Assumption, Avoyelles, East Baton Rouge, East Feliciana and 26 more	8 hr
Apr 25, 11:48 AM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more	117 min
Apr 25, 3:14 PM CDT	Mesoscale Discussion	SPC	Jefferson, Plaquemines, Saint Bernard	2 hr

Nearby

Mesoscale Discussions in Texas, 2019 Mesoscale Discussions in Louisiana, 2019 Every mesoscale discussion in 2019

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.