Alert archive / North Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1954

August 12, 201117 counties in Minnesota; 19 counties in North Dakota; 8 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 12, 2011, 1:18 PM CDT for 17 counties in Minnesota; 19 counties in North Dakota; 8 counties in South Dakota. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: Aug 12, 2011, 1:18 PM CDT (18:18 UTC)
Expired: Aug 12, 2011, 2:15 PM CDT
In force: 57 min
Issued by: the Storm Prediction Center

All 44 counties

Becker County, MN, Big Stone County, MN, Chippewa County, MN, Clay County, MN, Douglas County, MN, Grant County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Norman County, MN, Otter Tail County, MN, Pope County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Wilkin County, MN, Yellow Medicine County, MN, Barnes County, ND, Cass County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Nelson County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Traill County, ND, Wells County, ND, Brown County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Grant County, SD, Marshall County, SD, McPherson County, SD, Roberts County, SD

The radar

The Aberdeen radar (KABR), 126 km from the middle of the area, began a volume at 18:19 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 771Aug 12, 1:50 PM CDT

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 6.3 hours before the alert went out and 179 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: 9 J/kg
Mixed-layer CIN: -231 J/kg
Mixed-layer LCL: 847 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 18 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
Aug 11, 7:19 PM CDT	Severe Thunderstorm Watch	SPC	Pipestone, Rock	5 hr
Aug 11, 9:42 PM CDT	Mesoscale Discussion	SPC	Lincoln, Pipestone, Rock	63 min
Aug 12, 3:44 PM CDT	Mesoscale Discussion	SPC	Becker, Beltrami, Big Stone, Cass, Chippewa, Clay and 26 more	91 min
Aug 11, 7:16 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bowman, Hettinger, Slope	4 hr
Aug 11, 9:55 PM CDT	Mesoscale Discussion	SPC	Adams, Bowman, Hettinger, Slope	65 min
Aug 12, 1:47 PM CDT	Severe Thunderstorm Watch	SPC	Barnes, Benson, Cass, Dickey, Eddy, Foster and 13 more	6 hr

Nearby

Mesoscale Discussions in North Dakota, 2011 Mesoscale Discussions in Minnesota, 2011 Mesoscale Discussions in South 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.