Alert archive / Nebraska / Mesoscale Discussions in 2007

Mesoscale Discussion 682

May 4, 20074 counties in Iowa; 38 counties in Nebraska; 4 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 4, 2007, 1:19 PM CDT for 4 counties in Iowa; 38 counties in Nebraska; 4 counties in South Dakota. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: May 4, 2007, 1:19 PM CDT (18:19 UTC)
Expired: May 4, 2007, 2:45 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center

All 46 counties

Harrison County, IA, Mills County, IA, Monona County, IA, Pottawattamie County, IA, Antelope County, NE, Boone County, NE, Boyd County, NE, Buffalo County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Garfield County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Holt County, NE, Howard County, NE, Knox County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Wheeler County, NE, York County, NE, Bon Homme County, SD, Clay County, SD, Union County, SD, Yankton County, SD

The radar

The Omaha radar (KOAX), 120 km from the middle of the area, began a volume at 18:21 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.

Tornado Watch 226May 4, 2:25 PM CDT

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 6.3 hours before the alert went out and 120 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: 91 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 597 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 84 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
May 3, 7:34 PM CDT	Mesoscale Discussion	SPC	Banner, Cheyenne, Deuel, Kimball, Morrill, Scotts Bluff	26 min
May 3, 7:43 PM CDT	Tornado Watch	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more	5 hr
May 3, 9:57 PM CDT	Mesoscale Discussion	SPC	Cheyenne, Deuel, Garden, Kimball, Morrill	93 min
May 4, 2:24 PM CDT	Tornado Watch	SPC	Antelope, Blaine, Boone, Boyd, Brown, Buffalo and 22 more	7 hr
May 4, 5:07 PM CDT	Mesoscale Discussion	SPC	Chase, Dundy, Hayes, Hitchcock	83 min
May 4, 6:20 PM CDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boone, Boyd, Cedar, Custer and 16 more	85 min
May 4, 6:36 PM CDT	Tornado Watch	SPC	Chase, Deuel, Dundy, Frontier, Hayes, Hitchcock and 3 more	7 hr

Nearby

Mesoscale Discussions in Nebraska, 2007 Mesoscale Discussions in Iowa, 2007 Mesoscale Discussions in South Dakota, 2007 Every mesoscale discussion in 2007

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.