Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 1245

August 6, 2018Harrison County, Mills County, Pottawattamie County, Iowa; 32 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 6, 2018, 2:31 PM CDT for Harrison County, Mills County, Pottawattamie County, Iowa; 32 counties in Nebraska. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Aug 6, 2018, 2:31 PM CDT (19:31 UTC)
Expired: Aug 6, 2018, 4:00 PM CDT
In force: 89 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 35 counties

Harrison County, IA, Mills County, IA, Pottawattamie County, IA, Boone County, NE, Buffalo County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dodge County, NE, Douglas County, NE, Garfield County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Lancaster County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Otoe County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Valley County, NE, Washington County, NE, Wheeler County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 119 km from the middle of the area, began a volume at 19:32 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 nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.5 hours before the alert went out and 123 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: 94 J/kg
Mixed-layer CIN: -247 J/kg
Mixed-layer LCL: 731 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -49 m²/s²
0-3 km storm-relative helicity: -183 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

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
Aug 5, 9:32 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Boone, Butler, Calhoun and 29 more	2 hr
Aug 6, 6:38 PM CDT	Mesoscale Discussion	SPC	Adams, Appanoose, Clarke, Davis, Decatur, Fremont and 11 more	2 hr
Aug 5, 7:05 PM CDT	Mesoscale Discussion	SPC	Banner, Cheyenne, Kimball, Scotts Bluff, Sioux	115 min
Aug 5, 8:16 PM CDT	Mesoscale Discussion	SPC	Harlan	119 min
Aug 6, 3:02 PM CDT	Mesoscale Discussion	SPC	Banner, Kimball	88 min
Aug 6, 3:37 PM CDT	Severe Thunderstorm Watch	SPC	Banner, Cheyenne, Kimball, Morrill, Scotts Bluff	7 hr
Aug 6, 3:49 PM CDT	Mesoscale Discussion	SPC	Box Butte, Cherry, Dawes, Sheridan, Sioux	86 min
Aug 6, 6:24 PM CDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Kimball, Morrill, Scotts Bluff and 1 more	66 min

Nearby

Mesoscale Discussions in Nebraska, 2018 Mesoscale Discussions in Iowa, 2018 Every mesoscale discussion in 2018

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.