Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 1319

August 18, 2018Phillips County, Sedgwick County, Colorado; 11 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2018, 2:26 PM MDT for Phillips County, Sedgwick County, Colorado; 11 counties in Nebraska. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Aug 18, 2018, 2:26 PM MDT (20:26 UTC)
Expired: Aug 18, 2018, 5:00 PM MDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Phillips County, CO, Sedgwick County, CO, Arthur County, NE, Chase County, NE, Cherry County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, McPherson County, NE, Perkins County, NE, Sheridan County, NE

The radar

The North Platte radar (KLNX), 135 km from the middle of the area, began a volume at 20:28 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

Denver, CO (KDEN), launched 12:00Z, 8.4 hours before the alert went out and 205 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: 412 J/kg
Mixed-layer CIN: -229 J/kg
Mixed-layer LCL: 1881 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: 13 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 18, 12:25 PM MDT	Mesoscale Discussion	SPC	Baca, Bent, Cheyenne, Crowley, El Paso, Kiowa and 5 more	2 hr
Aug 18, 12:47 PM MDT	Severe Thunderstorm Watch	SPC	Baca, Bent, Cheyenne, Crowley, Elbert, El Paso and 8 more	7 hr
Aug 18, 2:50 PM MDT	Mesoscale Discussion	SPC	Baca, Bent, Cheyenne, Crowley, Elbert, El Paso and 7 more	55 min
Aug 18, 5:34 PM MDT	Mesoscale Discussion	SPC	Baca, Prowers	116 min

Nearby

Mesoscale Discussions in Nebraska, 2018 Mesoscale Discussions in Colorado, 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.