Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1759

July 26, 201110 counties in Minnesota; Richland County, North Dakota; 12 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2011, 8:10 PM CDT for 10 counties in Minnesota; Richland County, North Dakota; 12 counties in South Dakota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jul 26, 2011, 8:10 PM CDT (01:10 UTC)
Expired: Jul 26, 2011, 9:45 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

All 23 counties

Big Stone County, MN, Douglas County, MN, Grant County, MN, Lac qui Parle County, MN, Otter Tail County, MN, Pope County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Wilkin County, MN, Richland County, ND, Beadle County, SD, Brown County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Kingsbury County, SD, Marshall County, SD, Roberts County, SD, Spink County, SD

The radar

The Aberdeen radar (KABR), 108 km from the middle of the area, began a volume at 01:13 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

Aberdeen, SD (KABR), launched 00:00Z, 1.2 hours before the alert went out and 124 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: 3555 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 900 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 289 m²/s²
0-3 km storm-relative helicity: 399 m²/s²
Significant tornado parameter: 7.2
Supercell composite: 32.6

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 26, 7:24 PM CDT	Mesoscale Discussion	SPC	Big Stone, Grant, Stevens, Traverse, Wilkin	36 min
Jul 26, 7:32 PM CDT	Tornado Watch	SPC	Big Stone, Chippewa, Douglas, Grant, Lac qui Parle, Otter Tail and 6 more	5 hr
Jul 26, 8:17 PM CDT	Severe Thunderstorm Watch	SPC	Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more	8 hr
Jul 26, 9:53 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Chippewa, Cottonwood, Dakota and 37 more	67 min
Jul 26, 10:10 PM CDT	Severe Thunderstorm Watch	SPC	Anoka, Benton, Blue Earth, Brown, Carver, Chippewa and 30 more	8 hr
Jul 27, 2:49 AM CDT	Mesoscale Discussion	SPC	Anoka, Blue Earth, Brown, Carver, Chisago, Cottonwood and 29 more	56 min
Jul 26, 7:05 PM CDT	Mesoscale Discussion	SPC	Billings, Bowman, Divide, Golden Valley, McKenzie, Slope and 1 more	85 min
Jul 27, 3:49 PM CDT	Mesoscale Discussion	SPC	Custer, Fall River, Lawrence, Oglala Lakota, Pennington	86 min

Nearby

Mesoscale Discussions in South Dakota, 2011 Mesoscale Discussions in Minnesota, 2011 Mesoscale Discussions in North Dakota, 2011 Every mesoscale discussion in 2011

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.