Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1890

August 7, 201131 counties in Nebraska; 14 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2011, 6:35 PM CDT for 31 counties in Nebraska; 14 counties in South Dakota. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Aug 7, 2011, 6:35 PM CDT (23:35 UTC)
Expired: Aug 7, 2011, 8:30 PM CDT
In force: 115 min
Issued by: the Storm Prediction Center

All 45 counties

Adams County, NE, Arthur County, NE, Blaine County, NE, Boyd County, NE, Brown County, NE, Buffalo County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Garfield County, NE, Gosper County, NE, Grant County, NE, Greeley County, NE, Hall County, NE, Holt County, NE, Hooker County, NE, Howard County, NE, Kearney County, NE, Keith County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Phelps County, NE, Rock County, NE, Sheridan County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, Bennett County, SD, Butte County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 112 km from the middle of the area, began a volume at 23:39 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 741Aug 7, 7:50 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.6 hours before the alert went out and 203 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: 774 J/kg
Mixed-layer CIN: -261 J/kg
Mixed-layer LCL: 1513 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: -23 m²/s²
0-3 km storm-relative helicity: 264 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -1.3

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 6, 8:10 PM CDT	Mesoscale Discussion	SPC	Boone, Burt, Butler, Cass, Colfax, Cuming and 23 more	2 hr
Aug 7, 10:48 AM CDT	Mesoscale Discussion	SPC	Nuckolls, Thayer	117 min
Aug 7, 1:23 PM CDT	Mesoscale Discussion	SPC	Arthur, Blaine, Brown, Cherry, Custer, Grant and 5 more	67 min
Aug 7, 2:58 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Brown, Buffalo, Cherry, Custer and 21 more	8 hr

Nearby

Mesoscale Discussions in Nebraska, 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.