Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 437

April 7, 200326 parishes in Louisiana; 5 counties in Mississippi; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2003, 2:13 PM CDT for 26 parishes in Louisiana; 5 counties in Mississippi; 4 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Apr 7, 2003, 2:13 PM CDT (19:13 UTC)
Expired: Apr 7, 2003, 4:45 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 35 counties

Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Hancock County, MS, Harrison County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Chambers County, TX, Hardin County, TX, Jefferson County, TX, Orange County, TX

The radar

The Lake Charles radar (KLCH), 81 km from the middle of the area, began a volume at 19:16 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.

Severe Thunderstorm Watch 114Apr 7, 3:40 PM CDT

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.2 hours before the alert went out and 79 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: 1791 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 518 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: -64 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: -0.6
Supercell composite: -2.0

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 6, 8:13 PM CDT	Mesoscale Discussion	SPC	Catahoula, Concordia, Franklin, LaSalle, Tensas	2 hr
Apr 7, 9:42 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Beauregard, Calcasieu and 16 more	3 hr
Apr 7, 10:05 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 26 more	6 hr
Apr 7, 11:02 AM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Cameron, East Baton Rouge, Iberville, Lafayette and 8 more	3 hr
Apr 7, 2:36 PM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge and 20 more	114 min
Apr 7, 3:40 PM CDT	Severe Thunderstorm Watch	SPC	Acadia, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge and 22 more	5 hr
Apr 7, 5:58 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, Cameron, Iberia, Iberville, Lafayette and 10 more	2 hr
Apr 6, 9:48 PM CDT	Mesoscale Discussion	SPC	Clarke, Covington, Jasper, Jefferson Davis, Jones, Kemper and 5 more	87 min
Apr 7, 4:49 AM CDT	Mesoscale Discussion	SPC	Kemper, Lauderdale, Newton	3 hr
Apr 7, 9:11 AM CDT	Mesoscale Discussion	SPC	Forrest, George, Greene, Jones, Lamar, Pearl River and 2 more	3 hr
Apr 7, 11:25 AM CDT	Mesoscale Discussion	SPC	George, Greene	3 hr
Apr 7, 12:07 PM CDT	Mesoscale Discussion	SPC	George, Greene	113 min
Apr 7, 12:22 PM CDT	Mesoscale Discussion	SPC	George, Greene	113 min
Apr 7, 12:24 PM CDT	Mesoscale Discussion	SPC	Atascosa, Austin, Bastrop, Bee, Bexar, Brazoria and 28 more	66 min
Apr 7, 1:00 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Austin, Bee, Bexar, Brazoria, Caldwell and 23 more	5 hr
Apr 7, 3:36 PM CDT	Mesoscale Discussion	SPC	Edwards, Kinney, Maverick, Real, Uvalde, Val Verde	114 min
Apr 7, 4:35 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bee, Bexar, Blanco, Caldwell and 22 more	5 hr

Nearby

Mesoscale Discussions in Louisiana, 2003 Mesoscale Discussions in Mississippi, 2003 Mesoscale Discussions in Texas, 2003 Every mesoscale discussion in 2003

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.