Alert archive / Louisiana / Mesoscale Discussions in 2014

Mesoscale Discussion 285

April 4, 201421 parishes in Louisiana; 18 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2014, 5:04 AM CDT for 21 parishes in Louisiana; 18 counties in Mississippi. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2014, 5:04 AM CDT (10:04 UTC)
Expired
Apr 4, 2014, 7:00 AM CDT
In force
116 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 39 counties

Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Pointe Coupee 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, Tangipahoa Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Pike County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Wilkinson County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 10.1 hours before the alert went out and 181 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, Jackson, MS at 00:00Z on 2014-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 514 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, Jackson, MS at 00:00Z on 2014-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 square meters per square second.19395878Sfc1 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
514 J/kg
Mixed-layer CIN
-205 J/kg
Mixed-layer LCL
1384 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
218 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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 3, 8:44 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more31 min
Apr 3, 8:54 PM CDTTornado WatchSPCBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more7 hr
Apr 4, 12:20 AM CDTMesoscale DiscussionSPCCaldwell, Catahoula, East Carroll, Franklin, LaSalle, Madison and 5 more55 min
Apr 4, 12:40 AM CDTTornado WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more5 hr
Apr 4, 12:55 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 4 more95 min
Apr 4, 3:34 AM CDTSevere Thunderstorm WatchSPCAllen, Beauregard, Calcasieu, Caldwell, Cameron, De Soto and 9 more6 hr
Apr 4, 3:45 AM CDTMesoscale DiscussionSPCCaldwell, East Carroll, Franklin, Jackson, Madison, Morehouse and 4 more60 min
Apr 4, 5:25 AM CDTSevere Thunderstorm WatchSPCAcadia, Ascension, Assumption, Avoyelles, Catahoula, Concordia and 30 more7 hr
Apr 4, 5:28 AM CDTMesoscale DiscussionSPCCatahoula, Concordia, Madison, Tensas92 min
Apr 4, 5:49 AM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Caldwell, De Soto, Franklin and 8 more56 min
Apr 4, 7:22 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 26 more83 min
Apr 4, 10:12 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Avoyelles, Cameron, Catahoula and 28 more63 min
Apr 3, 10:45 PM CDTMesoscale DiscussionSPCBenton, Bolivar, Calhoun, Carroll, Coahoma, DeSoto and 16 more60 min
Apr 4, 2:29 AM CDTMesoscale DiscussionSPCAlcorn, Clay, Itawamba, Lee, Lowndes, Monroe and 3 more31 min
Apr 4, 2:52 AM CDTTornado WatchSPCClay, Kemper, Lauderdale, Lowndes, Neshoba, Newton and 4 more5 hr

Nearby

Mesoscale Discussions in Louisiana, 2014Mesoscale Discussions in Mississippi, 2014Every mesoscale discussion in 2014

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.