Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 535

May 1, 20049 counties in Arkansas; 16 parishes in Louisiana; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 1, 2004, 2:38 AM CDT for 9 counties in Arkansas; 16 parishes in Louisiana; 4 counties in Texas. It was in force for 37 min.

The area

The outline as issued.

The facts

Issued
May 1, 2004, 2:38 AM CDT (07:38 UTC)
Expired
May 1, 2004, 3:15 AM CDT
In force
37 min
Issued by
the Storm Prediction Center
All 29 counties

Bradley County, AR, Calhoun County, AR, Columbia County, AR, Hempstead County, AR, Lafayette County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 52 km from the middle of the area, began a volume at 07:38 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.

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 7.6 hours before the alert went out and 44 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-pSkew-T log-p diagram, Shreveport, LA at 00:00Z on 2004-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2142 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Shreveport, LA at 00:00Z on 2004-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
2142 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
1062 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
0.8
Supercell composite
5.2

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.

IssuedProductOfficeCountiesLasted
Apr 30, 7:06 PM CDTMesoscale DiscussionSPCBenton, Carroll, Crawford, Franklin, Logan, Madison and 3 more114 min
Apr 30, 7:22 PM CDTMesoscale DiscussionSPCHempstead, Howard, Little River, Miller, Sevier83 min
Apr 30, 7:40 PM CDTSevere Thunderstorm WatchSPCHoward, Little River, Pike, Sevier5 hr
Apr 30, 9:05 PM CDTSevere Thunderstorm WatchSPCBenton, Crawford, Sebastian, Washington5 hr
Apr 30, 9:54 PM CDTMesoscale DiscussionSPCHoward, Little River, Pike, Sevier96 min
Apr 30, 11:45 PM CDTMesoscale DiscussionSPCBenton, Crawford, Sebastian, Washington90 min
May 1, 12:50 AM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more6 hr
May 1, 1:11 AM CDTMesoscale DiscussionSPCCrawford, Sebastian, Washington64 min
May 1, 3:10 AM CDTSevere Thunderstorm WatchSPCAshley, Bradley, Calhoun, Cleveland, Columbia, Dallas and 5 more6 hr
May 1, 5:13 AM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Cleveland, Columbia, Dallas and 5 more92 min
Apr 30, 11:56 PM CDTMesoscale DiscussionSPCBeauregard, Calcasieu, Cameron, Jefferson Davis94 min
May 1, 7:24 AM CDTMesoscale DiscussionSPCNatchitoches, Sabine, Winn96 min
May 1, 9:45 AM CDTTornado WatchSPCAllen, Beauregard, Calcasieu, Cameron, Jefferson Davis, Vernon5 hr
May 1, 1:45 PM CDTMesoscale DiscussionSPCEast Baton Rouge, East Feliciana, Iberville, Livingston, Saint Helena, Saint Tammany and 3 more3 hr
May 1, 4:00 PM CDTSevere Thunderstorm WatchSPCWashington5 hr
Apr 30, 7:00 PM CDTMesoscale DiscussionSPCBosque, Brown, Coleman, Comanche, Concho, Eastland and 11 more90 min
Apr 30, 8:14 PM CDTMesoscale DiscussionSPCArcher, Clay, Collin, Cooke, Denton, Grayson and 8 more91 min
Apr 30, 9:07 PM CDTMesoscale DiscussionSPCBosque, Brown, Comanche, Coryell, Erath, Hamilton and 8 more53 min
Apr 30, 10:34 PM CDTMesoscale DiscussionSPCBrown, Coleman, Concho, Crockett, Edwards, Irion and 15 more86 min
Apr 30, 11:35 PM CDTSevere Thunderstorm WatchSPCBlanco, Concho, Crockett, Edwards, Gillespie, Irion and 13 more5 hr
May 1, 1:34 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Blanco, Comal, Concho and 24 more86 min
May 1, 1:49 AM CDTMesoscale DiscussionSPCAnderson, Bell, Cherokee, Falls, Freestone, Henderson and 5 more86 min
May 1, 3:28 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Blanco, Concho, Crockett and 23 more92 min
May 1, 3:41 AM CDTMesoscale DiscussionSPCAustin, Brazoria, Brazos, Burleson, Chambers, Colorado and 18 more64 min
May 1, 3:50 AM CDTTornado WatchSPCAngelina, Austin, Bastrop, Brazos, Burleson, Chambers and 25 more6 hr
May 1, 5:40 AM CDTSevere Thunderstorm WatchSPCAtascosa, Bee, Bexar, Caldwell, DeWitt, Dimmit and 17 more6 hr
May 1, 6:08 AM CDTMesoscale DiscussionSPCAngelina, Austin, Brazos, Burleson, Chambers, Colorado and 24 more97 min
May 1, 7:33 AM CDTMesoscale DiscussionSPCAtascosa, Bee, Bexar, Caldwell, DeWitt, Dimmit and 16 more87 min
May 1, 7:47 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Brazos, Burleson, Chambers, Colorado and 23 more88 min
May 1, 9:16 AM CDTMesoscale DiscussionSPCBrazoria, Chambers, Fort Bend, Galveston, Hardin, Harris and 3 more59 min
May 1, 9:36 AM CDTMesoscale DiscussionSPCNueces114 min
May 1, 9:55 AM CDTSevere Thunderstorm WatchSPCBrooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Kleberg and 3 more5 hr
May 1, 11:15 AM CDTMesoscale DiscussionSPCKenedy2 hr
May 1, 1:14 PM CDTMesoscale DiscussionSPCWillacy2 hr

Nearby

Mesoscale Discussions in Louisiana, 2004Mesoscale Discussions in Arkansas, 2004Mesoscale Discussions in Texas, 2004Every 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.