Alert archive / Louisiana / Mesoscale Discussions in 2023

Mesoscale Discussion 1149

June 18, 202321 parishes in Louisiana; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2023, 9:55 AM CDT for 21 parishes in Louisiana; 8 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 18, 2023, 9:55 AM CDT (14:55 UTC)
Expired: Jun 18, 2023, 12:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 332

All 29 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Claiborne County, MS, Hinds County, MS, Lauderdale County, MS, Leake County, MS, Neshoba County, MS, Newton County, MS, Rankin County, MS, Scott County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 118 km from the middle of the area, began a volume at 14:58 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 nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 2.9 hours before the alert went out and 109 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: 1451 J/kg
Mixed-layer CIN: -109 J/kg
Mixed-layer LCL: 796 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 251 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

<!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
Jun 18, 2:27 AM CDT	Severe Thunderstorm Watch	SPC	East Carroll, Franklin, Madison, Morehouse, Richland, Tensas and 1 more	10 hr
Jun 18, 5:21 AM CDT	Mesoscale Discussion	SPC	Madison	114 min
Jun 18, 7:08 AM CDT	Mesoscale Discussion	SPC	Bossier, Caddo	97 min
Jun 18, 3:12 PM CDT	Mesoscale Discussion	SPC	Caddo, De Soto	93 min
Jun 18, 3:45 PM CDT	Mesoscale Discussion	SPC	Tensas, Washington	90 min
Jun 18, 6:11 PM CDT	Mesoscale Discussion	SPC	East Carroll, Franklin, Madison, Morehouse, Ouachita, Richland and 2 more	64 min
Jun 18, 6:52 PM CDT	Tornado Watch	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more	6 hr
Jun 18, 2:01 AM CDT	Mesoscale Discussion	SPC	Bolivar, Coahoma, DeSoto, Humphreys, Leflore, Quitman and 4 more	119 min
Jun 18, 6:11 AM CDT	Severe Thunderstorm Watch	SPC	Covington, Forrest, George, Greene, Harrison, Jackson and 9 more	6 hr
Jun 18, 6:33 AM CDT	Mesoscale Discussion	SPC	Itawamba, Tishomingo	117 min
Jun 18, 11:32 AM CDT	Mesoscale Discussion	SPC	Clarke, George, Greene, Jackson, Jasper, Jones and 2 more	118 min
Jun 18, 5:31 PM CDT	Mesoscale Discussion	SPC	Benton, Bolivar, Calhoun, Coahoma, DeSoto, Grenada and 13 more	119 min

Nearby

Mesoscale Discussions in Louisiana, 2023 Mesoscale Discussions in Mississippi, 2023 Every mesoscale discussion in 2023

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.