Alert archive / Oklahoma / Mesoscale Discussions in 2007

Mesoscale Discussion 1828

August 20, 2007Barber County, Harper County, Kingman County, Kansas; 11 counties in Oklahoma; Hemphill County, Lipscomb County, Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 20, 2007, 11:11 PM CDT for Barber County, Harper County, Kingman County, Kansas; 11 counties in Oklahoma; Hemphill County, Lipscomb County, Texas. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Aug 20, 2007, 11:11 PM CDT (04:11 UTC)
Expired: Aug 21, 2007, 12:15 AM CDT
In force: 64 min
Issued by: the Storm Prediction Center

Counties Barber County, KS, Harper County, KS, Kingman County, KS, Alfalfa County, OK, Blaine County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Harper County, OK, Major County, OK, Roger Mills County, OK, Woods County, OK, Woodward County, OK, Hemphill County, TX, Lipscomb County, TX

The radar

The Vance AFB radar (KVNX), 100 km from the middle of the area, began a volume at 04:14 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

Lamont, OK (KLMN), launched 00:00Z, 4.2 hours before the alert went out and 154 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: 2658 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1347 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 58 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.2

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 20, 8:01 PM CDT	Mesoscale Discussion	SPC	Barber, Clark, Comanche, Edwards, Finney, Ford and 15 more	89 min
Aug 20, 9:13 PM CDT	Mesoscale Discussion	SPC	Barber, Barton, Butler, Chase, Clark, Coffey and 40 more	32 min
Aug 20, 9:45 PM CDT	Severe Thunderstorm Watch	SPC	Barber, Barton, Butler, Chase, Clark, Comanche and 25 more	3 hr
Aug 21, 2:47 PM CDT	Mesoscale Discussion	SPC	Cheyenne, Decatur, Rawlins, Sherman	118 min
Aug 21, 3:50 PM CDT	Severe Thunderstorm Watch	SPC	Cheyenne, Decatur, Gove, Graham, Greeley, Logan and 8 more	6 hr
Aug 21, 5:53 PM CDT	Mesoscale Discussion	SPC	Decatur, Greeley, Logan, Norton, Rawlins, Sheridan and 3 more	97 min

Nearby

Mesoscale Discussions in Oklahoma, 2007 Mesoscale Discussions in Kansas, 2007 Mesoscale Discussions in Texas, 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.