Alert archive / South Dakota / Mesoscale Discussions in 2020

Mesoscale Discussion 826

June 4, 2020Keya Paha County, Nebraska; 17 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2020, 6:55 PM CDT for Keya Paha County, Nebraska; 17 counties in South Dakota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jun 4, 2020, 6:55 PM CDT (23:55 UTC)
Expired: Jun 4, 2020, 8:30 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 252

Counties Keya Paha County, NE, Bennett County, SD, Brule County, SD, Buffalo County, SD, Custer County, SD, Gregory County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Lyman County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD

The radar

The Rapid City radar (KUDX), 62 km from the middle of the area, began a volume at 23:54 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 254Jun 4, 7:40 PM CDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 11.9 hours before the alert went out and 63 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: 1303 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 350 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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
Jun 3, 8:54 PM CDT	Mesoscale Discussion	SPC	Adams, Clay, Fillmore, Franklin, Gage, Hall and 17 more	2 hr
Jun 3, 9:38 PM CDT	Severe Thunderstorm Watch	SPC	Gage, Jefferson, Johnson, Lancaster, Nemaha, Otoe and 4 more	6 hr
Jun 3, 10:44 PM CDT	Mesoscale Discussion	SPC	Cass, Gage, Jefferson, Johnson, Lancaster, Nemaha and 7 more	2 hr
Jun 4, 2:25 PM CDT	Mesoscale Discussion	SPC	Boyd, Brown, Cherry, Keya Paha, Rock	95 min
Jun 4, 5:23 PM CDT	Mesoscale Discussion	SPC	Blaine, Cherry, Frontier, Hayes, Hitchcock, Hooker and 5 more	2 hr
Jun 4, 3:27 PM CDT	Severe Thunderstorm Watch	SPC	Bennett, Butte, Custer, Dewey, Haakon, Harding and 15 more	8 hr
Jun 4, 5:14 PM CDT	Mesoscale Discussion	SPC	Lincoln	91 min

Nearby

Mesoscale Discussions in South Dakota, 2020 Mesoscale Discussions in Nebraska, 2020 Every mesoscale discussion in 2020

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.