Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 1960

August 11, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2004, 12:22 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 11, 2004, 12:22 PM CDT (17:22 UTC)
Expired: Aug 11, 2004, 2:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 50 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Columbia County, AR, Desha County, AR, Drew County, AR, Lafayette County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Panola County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Washington County, MS, Yalobusha County, MS, Cherokee County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Nacogdoches County, TX, Panola County, TX, Rusk County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 131 km from the middle of the area, began a volume at 17:25 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 nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 5.4 hours before the alert went out and 122 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: 189 J/kg
Mixed-layer CIN: -112 J/kg
Mixed-layer LCL: 1474 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -18 m²/s²
0-3 km storm-relative helicity: -49 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Aug 11, 1:07 AM CDT	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Cleburne, Conway and 30 more	113 min
Aug 11, 1:35 AM CDT	Severe Thunderstorm Watch	SPC	Baxter, Benton, Boone, Carroll, Cleburne, Conway and 37 more	5 hr
Aug 11, 5:23 AM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Cleburne, Conway, Craighead, Crawford and 27 more	97 min
Aug 11, 6:49 AM CDT	Mesoscale Discussion	SPC	Conway, Crawford, Faulkner, Franklin, Garland, Hot Spring and 20 more	116 min
Aug 10, 11:30 PM CDT	Severe Thunderstorm Watch	SPC	Hansford, Hartley, Hemphill, Hutchinson, Lipscomb, Moore and 3 more	5 hr
Aug 11, 1:05 AM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Briscoe, Carson, Childress, Clay, Collingsworth and 14 more	6 hr
Aug 11, 2:42 AM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Carson, Childress, Clay, Collingsworth and 15 more	2 hr
Aug 11, 1:16 PM CDT	Mesoscale Discussion	SPC	Anderson, Austin, Bandera, Bastrop, Bell, Bexar and 44 more	2 hr

Nearby

Mesoscale Discussions in Louisiana, 2004 Mesoscale Discussions in Mississippi, 2004 Mesoscale Discussions in Arkansas, 2004 Every mesoscale discussion in 2004

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.