Alert archive / Oklahoma / Mesoscale Discussions in 2015

Mesoscale Discussion 688

May 18, 201511 counties in Oklahoma; Clay County, Montague County, Wichita County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 18, 2015, 1:07 PM CDT for 11 counties in Oklahoma; Clay County, Montague County, Wichita County, Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: May 18, 2015, 1:07 PM CDT (18:07 UTC)
Expired: May 18, 2015, 2:00 PM CDT
In force: 53 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Carter County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Pontotoc County, OK, Stephens County, OK, Clay County, TX, Montague County, TX, Wichita County, TX

The nearest sounding before it

Shreveport, LA (KBAD), launched 12:00Z, 6.1 hours before the alert went out and 378 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: 840 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.6

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 18, 2:58 PM CDT	Mesoscale Discussion	SPC	Carter, Comanche, Cotton, Garvin, Jackson, Jefferson and 6 more	2 hr
May 18, 2:16 PM CDT	Mesoscale Discussion	SPC	Andrews, Brewster, Crane, Ector, Jeff Davis, Loving and 8 more	59 min
May 18, 2:36 PM CDT	Severe Thunderstorm Watch	SPC	Andrews, Brewster, Crane, Ector, Jeff Davis, Loving and 7 more	7 hr
May 18, 6:00 PM CDT	Mesoscale Discussion	SPC	Andrews, Brewster, Crane, Ector, Gaines, Jeff Davis and 8 more	2 hr

Nearby

Mesoscale Discussions in Oklahoma, 2015 Mesoscale Discussions in Texas, 2015 Every mesoscale discussion in 2015

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.