Alert archive / Mississippi / Mesoscale Discussions in 2007

Mesoscale Discussion 2158

November 21, 200728 counties in Mississippi; Hardin County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Nov 21, 2007, 9:57 PM CST for 28 counties in Mississippi; Hardin County, Tennessee. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Nov 21, 2007, 9:57 PM CST (03:57 UTC)
Expired: Nov 21, 2007, 11:00 PM CST
In force: 63 min
Issued by: the Storm Prediction Center

All 29 counties

Alcorn County, MS, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Itawamba County, MS, Leake County, MS, Lee County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS, Hardin County, TN

The radar

The Jackson/Brandon,MS radar (KDGX), 74 km from the middle of the area, began a volume at 03:58 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 00:00Z, 4.0 hours before the alert went out and 76 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: 586 J/kg
Mixed-layer CIN: -53 J/kg
Mixed-layer LCL: 1050 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 176 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.7

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
Nov 21, 7:33 PM CST	Mesoscale Discussion	SPC	Adams, Alcorn, Amite, Attala, Benton, Bolivar and 51 more	87 min

Nearby

Mesoscale Discussions in Mississippi, 2007 Mesoscale Discussions in Tennessee, 2007 Every mesoscale discussion in 2007

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.