Alert archive / South Carolina / Mesoscale Discussions in 2013

Mesoscale Discussion 455

April 12, 201311 counties in Georgia; Columbus County, North Carolina; 27 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2013, 12:46 AM EDT for 11 counties in Georgia; Columbus County, North Carolina; 27 counties in South Carolina. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2013, 12:46 AM EDT (04:46 UTC)
Expired
Apr 12, 2013, 2:15 AM EDT
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 39 counties

Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Screven County, GA, Tattnall County, GA, Toombs County, GA, Columbus County, NC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Chesterfield County, SC, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Richland County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 51 km from the middle of the area, began a volume at 04:49 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 4.8 hours before the alert went out and 347 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, Greensboro/Hi Pt, NC at 00:00Z on 2013-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 29 joules per kilogram.LCLLFCEL10008507005003002001001 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, Greensboro/Hi Pt, NC at 00:00Z on 2013-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 square meters per square second.19395878Sfc1 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
29 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
1610 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
100 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.

IssuedProductOfficeCountiesLasted
Apr 11, 8:24 PM EDTTornado WatchSPCBaker, Baldwin, Banks, Barrow, Bartow, Ben Hill and 121 more8 hr
Apr 11, 10:52 PM EDTMesoscale DiscussionSPCBaker, Baldwin, Banks, Barrow, Bibb, Bleckley and 75 more83 min
Apr 12, 1:06 AM EDTTornado WatchSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 22 more6 hr
Apr 11, 9:19 PM EDTMesoscale DiscussionSPCCherokee, Graham, Haywood, Jackson, Macon, Madison and 1 more86 min
Apr 12, 1:58 AM EDTMesoscale DiscussionSPCAlamance, Bertie, Caswell, Chatham, Cumberland, Davidson and 34 more92 min
Apr 12, 2:57 AM EDTTornado WatchSPCAlamance, Anson, Chatham, Cumberland, Davidson, Durham and 25 more6 hr
Apr 12, 4:00 AM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, New Hanover, Pender, Robeson and 1 more90 min
Apr 12, 5:21 AM EDTTornado WatchSPCNorthampton3 hr
Apr 12, 7:25 AM EDTMesoscale DiscussionSPCEdgecombe, Franklin, Greene, Halifax, Johnston, Nash and 6 more65 min
Apr 12, 2:34 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Camden, Chowan, Columbus and 15 more116 min

Nearby

Mesoscale Discussions in South Carolina, 2013Mesoscale Discussions in Georgia, 2013Mesoscale Discussions in North Carolina, 2013Every mesoscale discussion in 2013

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.