Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 915

May 23, 201121 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 23, 2011, 9:22 PM CDT for 21 counties in Oklahoma. It was in force for 23 min.

The area

The outline as issued.

The facts

Issued: May 23, 2011, 9:22 PM CDT (02:22 UTC)
Expired: May 23, 2011, 9:45 PM CDT
In force: 23 min
Issued by: the Storm Prediction Center

All 21 counties

Adair County, OK, Blaine County, OK, Canadian County, OK, Cherokee County, OK, Creek County, OK, Haskell County, OK, Hughes County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Payne County, OK, Pittsburg County, OK, Pottawatomie County, OK, Seminole County, OK, Sequoyah County, OK, Wagoner County, OK

The radar

The Norman radar (KTLX), 60 km from the middle of the area, began a volume at 02:23 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.

Severe Thunderstorm Watch 350May 23, 9:45 PM CDT

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 2.4 hours before the alert went out and 77 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: 2770 J/kg
Mixed-layer CIN: -141 J/kg
Mixed-layer LCL: 888 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 319 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 12.4

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 23, 7:50 PM CDT	Mesoscale Discussion	SPC	Comanche, Cotton, Jackson, Jefferson, Stephens, Tillman	55 min
May 23, 9:42 PM CDT	Severe Thunderstorm Watch	SPC	Blaine, Caddo, Canadian, Cleveland, Creek, Grady and 18 more	6 hr
May 24, 2:08 AM CDT	Mesoscale Discussion	SPC	Cherokee, Creek, Haskell, LeFlore, McIntosh, Muskogee and 5 more	97 min
May 24, 12:18 PM CDT	Mesoscale Discussion	SPC	Blaine, Caddo, Canadian, Carter, Cleveland, Comanche and 21 more	87 min
May 24, 12:47 PM CDT	Tornado Watch PDS	SPC	Alfalfa, Atoka, Blaine, Bryan, Caddo, Canadian and 51 more	11 hr
May 24, 2:35 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Grant, Kay, Woods	85 min
May 24, 4:48 PM CDT	Mesoscale Discussion	SPC	Caddo, Canadian, Carter, Cleveland, Cotton, Creek and 21 more	87 min
May 24, 6:43 PM CDT	Mesoscale Discussion	SPC	Bryan, Carter, Cleveland, Coal, Creek, Garvin and 17 more	62 min

Nearby

Mesoscale Discussions in Oklahoma, 2011 Every mesoscale discussion in 2011

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.