Alert archive / Louisiana / Mesoscale Discussions in 2006

Mesoscale Discussion 595

April 20, 200616 parishes in Louisiana; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2006, 11:26 PM CDT for 16 parishes in Louisiana; 11 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Apr 20, 2006, 11:26 PM CDT (04:26 UTC)
Expired: Apr 21, 2006, 1:00 AM CDT
In force: 94 min
Issued by: the Storm Prediction Center

All 27 counties

Beauregard Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, De Soto Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Jasper County, TX, Nacogdoches County, TX, Newton County, TX, Panola County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 4.4 hours before the alert went out and 139 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: 479 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1245 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -34 m²/s²
0-3 km storm-relative helicity: -15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 10:00 PM CDT	Severe Thunderstorm Watch	SPC	Bossier, Caddo, Claiborne, De Soto, Union, Webster	7 hr
Apr 21, 2:15 AM CDT	Mesoscale Discussion	SPC	Lincoln, Union	2 hr
Apr 21, 9:51 AM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge and 23 more	84 min
Apr 21, 10:16 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Ascension, Assumption, Avoyelles, Catahoula, Concordia and 30 more	6 hr
Apr 21, 12:52 PM CDT	Mesoscale Discussion	SPC	Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more	83 min
Apr 21, 1:12 AM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 26 more	2 hr
Apr 21, 3:54 AM CDT	Severe Thunderstorm Watch	SPC	Bastrop, Caldwell, DeWitt, Fayette, Gonzales, Guadalupe and 4 more	106 min
Apr 21, 4:13 AM CDT	Mesoscale Discussion	SPC	Aransas, Atascosa, Austin, Bastrop, Bee, Bexar and 31 more	2 hr
Apr 21, 4:32 AM CDT	Severe Thunderstorm Watch	SPC	Aransas, Austin, Brazoria, Calhoun, Chambers, Colorado and 12 more	4 hr
Apr 21, 6:38 AM CDT	Mesoscale Discussion	SPC	Brazoria, Calhoun, Chambers, Galveston, Harris, Jefferson and 2 more	2 hr

Nearby

Mesoscale Discussions in Louisiana, 2006 Mesoscale Discussions in Texas, 2006 Every mesoscale discussion in 2006

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.