Alert archive / Alabama / Mesoscale Discussions in 2016

Mesoscale Discussion 1843

November 29, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Nov 29, 2016, 5:24 PM CST for 4 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Nov 29, 2016, 5:24 PM CST (23:24 UTC)
Expired: Nov 29, 2016, 7:00 PM CST
In force: 96 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 25 counties

Colbert County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Winston County, AL, Dade County, GA, Itawamba County, MS, Tishomingo County, MS, Bedford County, TN, Coffee County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Lawrence County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Moore County, TN, Wayne County, TN

The radar

The Northeast Alabama radar (KHTX), 81 km from the middle of the area, began a volume at 23:24 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

Nashville Metro, TN (KBNA), launched 12:00Z, 11.4 hours before the alert went out and 149 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1116 m above ground
0-6 km bulk shear: 81 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Nov 28, 6:36 PM CST	Mesoscale Discussion	SPC	Choctaw, Clarke, Monroe, Washington	2 hr
Nov 28, 7:00 PM CST	Mesoscale Discussion	SPC	Bibb, Blount, Chilton, Cullman, DeKalb, Etowah and 7 more	90 min
Nov 28, 8:39 PM CST	Mesoscale Discussion	SPC	Choctaw, Washington	96 min
Nov 28, 11:38 PM CST	Mesoscale Discussion	SPC	Autauga, Butler, Clarke, Dallas, Elmore, Lowndes and 5 more	3 hr
Nov 29, 3:08 PM CST	Mesoscale Discussion	SPC	Colbert, Franklin, Lamar, Lauderdale, Marion	2 hr
Nov 29, 3:48 PM CST	Tornado Watch	SPC	Colbert, Franklin, Lauderdale	7 hr
Nov 29, 4:46 PM CST	Mesoscale Discussion	SPC	Fayette, Greene, Hale, Lamar, Marion, Pickens and 2 more	2 hr
Nov 29, 5:37 PM CST	Tornado Watch	SPC	Fayette, Greene, Hale, Lamar, Marion, Pickens and 4 more	3 hr
Nov 29, 12:38 PM CST	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Covington, Franklin and 18 more	2 hr
Nov 29, 1:48 PM CST	Tornado Watch	SPC	Adams, Attala, Bolivar, Carroll, Choctaw, Claiborne and 27 more	7 hr
Nov 29, 4:20 PM CST	Mesoscale Discussion	SPC	Attala, Carroll, Choctaw, Claiborne, Copiah, Hinds and 17 more	55 min

Nearby

Mesoscale Discussions in Alabama, 2016 Mesoscale Discussions in Tennessee, 2016 Mesoscale Discussions in Mississippi, 2016 Every mesoscale discussion in 2016

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.