Alert archive / Louisiana / Mesoscale Discussions in 2008

Mesoscale Discussion 285

February 21, 200838 parishes in Louisiana; 6 counties in Mississippi; Jasper County, Newton County, Orange County, Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2008, 10:31 PM CST for 38 parishes in Louisiana; 6 counties in Mississippi; Jasper County, Newton County, Orange County, Texas. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: Feb 21, 2008, 10:31 PM CST (04:31 UTC)
Expired: Feb 22, 2008, 12:30 AM CST
In force: 119 min
Issued by: the Storm Prediction Center

All 47 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Bernard 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, Terrebonne Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Stone County, MS, Wilkinson County, MS, Jasper County, TX, Newton County, TX, Orange County, TX

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 4.5 hours before the alert went out and 170 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: 1139 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 643 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 3.1

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.

Issued	Product	Office	Counties	Lasted
Feb 21, 6:53 PM CST	Severe Thunderstorm Watch	SPC	Bienville, Caldwell, Catahoula, Claiborne, Concordia, East Carroll and 13 more	7 hr
Feb 21, 7:22 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more	83 min
Feb 21, 8:54 PM CST	Tornado Watch	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 27 more	7 hr
Feb 21, 10:59 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more	2 hr
Feb 22, 1:05 AM CST	Mesoscale Discussion	SPC	Attala, Carroll, Choctaw, Holmes, Humphreys, Issaquena and 15 more	55 min
Feb 22, 1:44 AM CST	Severe Thunderstorm Watch	SPC	Clarke, Copiah, Covington, Franklin, Jasper, Jefferson Davis and 12 more	5 hr
Feb 22, 4:41 AM CST	Mesoscale Discussion	SPC	Clarke, Covington, Forrest, Jones, Lamar, Marion and 2 more	64 min
Feb 22, 5:13 AM CST	Mesoscale Discussion	SPC	Austin, Bastrop, Caldwell, Colorado, DeWitt, Fayette and 7 more	92 min

Nearby

Mesoscale Discussions in Louisiana, 2008 Mesoscale Discussions in Mississippi, 2008 Mesoscale Discussions in Texas, 2008 Every mesoscale discussion in 2008

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.