Alert archive / Tennessee / Mesoscale Discussions in 2015

Mesoscale Discussion 2047

December 23, 201513 counties in Alabama; 44 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Dec 23, 2015, 4:26 PM CST for 13 counties in Alabama; 44 counties in Tennessee. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Dec 23, 2015, 4:26 PM CST (22:26 UTC)
Expired: Dec 23, 2015, 5:30 PM CST
In force: 64 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 57 counties

Blount County, AL, Colbert County, AL, Cullman 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, Bedford County, TN, Bledsoe County, TN, Cannon County, TN, Cheatham County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Moore County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Sequatchie County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 46 km from the middle of the area, began a volume at 22:25 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, 10.4 hours before the alert went out and 110 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: 596 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 194 m²/s²
0-3 km storm-relative helicity: 164 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Dec 23, 11:42 AM CST	Mesoscale Discussion	SPC	Barbour, Bullock, Coffee, Covington, Crenshaw, Dale and 4 more	93 min
Dec 23, 1:33 PM CST	Mesoscale Discussion	SPC	Autauga, Chilton, Choctaw, Clarke, Dallas, Greene and 7 more	57 min
Dec 23, 2:17 PM CST	Tornado Watch	SPC	Autauga, Bibb, Chilton, Choctaw, Clarke, Dallas and 11 more	6 hr
Dec 23, 2:49 PM CST	Mesoscale Discussion	SPC	Lauderdale	86 min
Dec 23, 4:49 PM CST	Tornado Watch	SPC	Colbert, Cullman, Franklin, Lauderdale, Lawrence, Limestone and 2 more	6 hr
Dec 23, 5:12 PM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Butler, Chilton, Choctaw, Clarke and 12 more	63 min
Dec 23, 6:13 AM CST	Mesoscale Discussion	SPC	Lake, Obion	2 hr
Dec 23, 9:05 AM CST	Mesoscale Discussion	SPC	Dyer, Lake, Lauderdale, Obion, Shelby, Tipton and 1 more	85 min
Dec 23, 9:13 AM CST	Tornado Watch	SPC	Crockett, Dyer, Gibson, Lake, Lauderdale, Obion and 1 more	8 hr
Dec 23, 10:58 AM CST	Mesoscale Discussion	SPC	Carroll, Chester, Crockett, Decatur, Dyer, Fayette and 9 more	2 hr
Dec 23, 11:57 AM CST	Tornado Watch PDS	SPC	Benton, Carroll, Chester, Decatur, Fayette, Hardeman and 8 more	9 hr
Dec 23, 12:48 PM CST	Mesoscale Discussion	SPC	Crockett, Dyer, Fayette, Gibson, Hardeman, Haywood and 4 more	57 min

Nearby

Mesoscale Discussions in Tennessee, 2015 Mesoscale Discussions in Alabama, 2015 Every mesoscale discussion in 2015

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.