Alert archive / Mississippi / Mesoscale Discussions in 2011

Mesoscale Discussion 436

April 15, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2011, 10:28 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2011, 10:28 AM CDT (15:28 UTC)
Expired
Apr 15, 2011, 12:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 99 counties

Autauga County, AL, Baldwin County, AL, Bibb County, AL, Blount County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Cullman County, AL, Dallas County, AL, Escambia County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lawrence County, AL, Limestone County, AL, Lowndes County, AL, Madison County, AL, Marengo County, AL, Marshall County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Wilcox County, AL, Winston County, AL, Escambia County, FL, Santa Rosa County, FL, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Richland Parish, LA, Tensas Parish, LA, Washington Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hinds County, MS, Holmes County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Warren County, MS, Wayne County, MS, Wilkinson County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 113 km from the middle of the area, began a volume at 15:29 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

Jackson, MS (KJAN), launched 12:00Z, 3.5 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-pSkew-T log-p diagram, Jackson, MS at 12:00Z on 2011-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1458 joules per kilogram.LCLEL10008507005003002001001 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 12:00Z on 2011-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 382 square meters per square second.1939587897Sfc1 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
1458 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
523 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
382 m²/s²
0-3 km storm-relative helicity
565 m²/s²
Significant tornado parameter
4.0
Supercell composite
14.6

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 15, 4:21 AM CDTMesoscale DiscussionSPCColbert, Franklin, Lamar, Lauderdale, Marion, Pickens84 min
Apr 15, 7:32 AM CDTTornado WatchSPCBlount, Choctaw, Clarke, Colbert, Cullman, Fayette and 20 more7 hr
Apr 15, 11:21 AM CDTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 44 more9 hr
Apr 15, 1:30 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Butler, Calhoun and 46 more2 hr
Apr 15, 3:35 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Butler, Chambers and 39 more85 min
Apr 15, 5:57 PM CDTMesoscale DiscussionSPCColbert, Franklin, Lamar, Lauderdale, Lawrence, Marion2 hr
Apr 14, 11:24 PM CDTSevere Thunderstorm WatchSPCBossier, Caddo, Claiborne, De Soto, Webster3 hr
Apr 14, 11:56 PM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto, Webster94 min
Apr 15, 1:27 AM CDTMesoscale DiscussionSPCBienville, Bossier, Claiborne, East Carroll, Jackson, Lincoln and 5 more93 min
Apr 15, 2:19 AM CDTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more8 hr
Apr 15, 2:41 PM CDTTornado WatchSPCAcadia, Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge and 19 more7 hr
Apr 15, 6:09 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 12 more96 min
Apr 15, 12:29 PM CDTMesoscale DiscussionSPCAlcorn, Benton, DeSoto, Lafayette, Marshall, Panola and 4 more61 min
Apr 15, 2:09 PM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, DeSoto, Itawamba and 13 more7 hr

Nearby

Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Alabama, 2011Mesoscale Discussions in Louisiana, 2011Every mesoscale discussion in 2011

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.