Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 411

April 6, 200320 parishes in Louisiana; Claiborne County, Issaquena County, Warren County, Mississippi; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2003, 12:03 PM CDT for 20 parishes in Louisiana; Claiborne County, Issaquena County, Warren County, Mississippi; 5 counties in Texas. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Apr 6, 2003, 12:03 PM CDT (17:03 UTC)
Expired
Apr 6, 2003, 2:00 PM CDT
In force
117 min
Issued by
the Storm Prediction Center
All 28 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Claiborne County, MS, Issaquena County, MS, Warren County, MS, Gregg County, TX, Harrison County, TX, Marion County, TX, Panola County, TX, Rusk County, TX

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 12:00Z, 5.1 hours before the alert went out and 56 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 12:00Z on 2003-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1292 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 12:00Z on 2003-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 259 square meters per square second.1939587897117Sfc1 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
1292 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
492 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
259 m²/s²
0-3 km storm-relative helicity
405 m²/s²
Significant tornado parameter
2.5
Supercell composite
20.3

Open this sounding in Storm Lab

The text

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

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 7:38 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 16 more97 min
Apr 6, 7:50 AM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Claiborne, East Carroll, Franklin and 9 more5 hr
Apr 6, 10:00 AM CDTMesoscale DiscussionSPCEast Carroll, Madison, West Carroll2 hr
Apr 6, 10:20 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 16 more55 min
Apr 6, 10:30 AM CDTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more6 hr
Apr 6, 3:26 PM CDTMesoscale DiscussionSPCBienville, Caldwell, De Soto, Franklin, Grant, Jackson and 11 more2 hr
Apr 6, 3:45 PM CDTTornado WatchSPCAllen, Avoyelles, Beauregard, Bienville, Bossier, Caddo and 26 more5 hr
Apr 6, 5:35 PM CDTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Bienville, Bossier, Caddo and 26 more115 min
Apr 6, 6:23 PM CDTMesoscale DiscussionSPCAvoyelles, Beauregard, Bienville, Bossier, Caldwell, Catahoula and 23 more97 min
Apr 6, 6:50 PM CDTTornado WatchSPCAvoyelles, Caldwell, Catahoula, Concordia, East Carroll, Evangeline and 11 more6 hr
Apr 6, 11:05 AM CDTSevere Thunderstorm WatchSPCAlcorn, Benton, Bolivar, Calhoun, Chickasaw, Coahoma and 15 more5 hr
Apr 6, 12:27 PM CDTMesoscale DiscussionSPCBenton, Coahoma, DeSoto, Lafayette, Marshall, Panola and 8 more2 hr
Apr 6, 12:40 PM CDTMesoscale DiscussionSPCAttala, Choctaw, Holmes, Kemper, Lauderdale, Leake and 9 more2 hr
Apr 6, 1:35 PM CDTTornado WatchSPCChoctaw, Clarke, Jasper, Jones, Kemper, Lauderdale and 7 more5 hr
Apr 6, 2:56 PM CDTMesoscale DiscussionSPCKemper, Lauderdale, Leake, Neshoba, Newton, Noxubee and 2 more2 hr
Apr 5, 6:11 PM CSTMesoscale DiscussionSPCBaylor, Briscoe, Cottle, Crosby, Dickens, Floyd and 9 more64 min
Apr 5, 6:35 PM CSTMesoscale DiscussionSPCArcher, Clay, Collin, Cooke, Dallas, Delta and 23 more115 min
Apr 5, 6:40 PM CSTTornado WatchSPCBriscoe, Childress, Cottle, Crosby, Dickens, Fisher and 16 more5 hr
Apr 5, 8:04 PM CSTMesoscale DiscussionSPCArcher, Baylor, Clay, Collin, Cooke, Dallas and 25 more116 min
Apr 5, 9:20 PM CSTMesoscale DiscussionSPCArcher, Camp, Clay, Collin, Cooke, Dallas and 31 more55 min
Apr 5, 9:35 PM CSTTornado WatchSPCArcher, Bowie, Camp, Cass, Clay, Collin and 38 more5 hr
Apr 5, 10:26 PM CSTMesoscale DiscussionSPCBaylor, Childress, Cottle, Dickens, Fisher, Foard and 11 more64 min
Apr 5, 11:43 PM CSTMesoscale DiscussionSPCArcher, Camp, Clay, Collin, Cooke, Dallas and 31 more92 min
Apr 6, 3:13 AM CDTMesoscale DiscussionSPCArcher, Baylor, Camp, Cass, Cherokee, Clay and 39 more107 min
Apr 6, 3:39 AM CDTMesoscale DiscussionSPCArcher, Baylor, Camp, Cass, Cherokee, Clay and 39 more66 min
Apr 6, 4:50 AM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Coke, Coleman and 27 more115 min
Apr 6, 5:35 AM CDTSevere Thunderstorm WatchSPCWichita4 hr
Apr 6, 9:12 AM CDTMesoscale DiscussionSPCAnderson, Bosque, Camp, Cass, Cherokee, Collin and 41 more2 hr
Apr 6, 12:40 PM CDTTornado WatchSPCAnderson, Brazos, Burleson, Cherokee, Collin, Cooke and 33 more5 hr
Apr 6, 2:55 PM CDTSevere Thunderstorm WatchSPCBowie, Delta, Lamar, Red River5 hr
Apr 6, 3:00 PM CDTMesoscale DiscussionSPCAnderson, Brazos, Cherokee, Delta, Freestone, Grimes and 21 more90 min

Nearby

Mesoscale Discussions in Louisiana, 2003Mesoscale Discussions in Texas, 2003Mesoscale Discussions in Mississippi, 2003Every 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.