Alert archive / South Dakota / Mesoscale Discussions in 2005

Mesoscale Discussion 1819

July 21, 20056 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2005, 6:23 PM MDT for 6 counties in South Dakota. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Jul 21, 2005, 6:23 PM MDT (00:23 UTC)
Expired: Jul 21, 2005, 7:30 PM MDT
In force: 67 min
Issued by: the Storm Prediction Center

Counties Haakon County, SD, Jones County, SD, Meade County, SD, Pennington County, SD, Stanley County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 72 km from the middle of the area, began a volume at 00:22 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.

Severe Thunderstorm Watch 658Jul 21, 6:30 PM MDT

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 0.4 hours before the alert went out and 271 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: 1122 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 1835 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 198 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 5.1

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
Jul 21, 6:30 PM MDT	Severe Thunderstorm Watch	SPC	Dewey, Haakon, Jackson, Jones, Meade, Pennington and 2 more	5 hr
Jul 21, 8:16 PM MDT	Mesoscale Discussion	SPC	Campbell, Corson, Dewey, Haakon, Jackson, Jones and 7 more	89 min
Jul 21, 10:25 PM MDT	Mesoscale Discussion	SPC	Bennett, Jackson, Oglala Lakota	65 min

Nearby

Mesoscale Discussions in South Dakota, 2005 Every mesoscale discussion in 2005

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.