Alert archive / Oklahoma / Mesoscale Discussions in 2020

Mesoscale Discussion 534

May 4, 202017 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 4, 2020, 3:46 PM CDT for 17 counties in Oklahoma. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: May 4, 2020, 3:46 PM CDT (20:46 UTC)
Expired: May 4, 2020, 5:45 PM CDT
In force: 119 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Carter County, OK, Cleveland County, OK, Garvin County, OK, Jefferson County, OK, Johnston County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Oklahoma County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 47 km from the middle of the area, began a volume at 20:47 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 165May 4, 4:40 PM CDT

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 8.8 hours before the alert went out and 38 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: 1672 J/kg
Mixed-layer CIN: -406 J/kg
Mixed-layer LCL: 989 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 431 m²/s²
0-3 km storm-relative helicity: 411 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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
May 4, 9:00 AM CDT	Mesoscale Discussion	SPC	Adair, Craig, Delaware, Ottawa, Sequoyah	90 min
May 4, 1:21 PM CDT	Mesoscale Discussion	SPC	Adair, Cherokee, Craig, Delaware, Mayes, Muskogee and 8 more	114 min
May 4, 2:32 PM CDT	Tornado Watch	SPC	Adair, Cherokee, Coal, Craig, Creek, Delaware and 21 more	9 hr
May 4, 4:38 PM CDT	Severe Thunderstorm Watch	SPC	Atoka, Bryan, Carter, Cleveland, Garvin, Jefferson and 7 more	5 hr
May 4, 6:42 PM CDT	Mesoscale Discussion	SPC	Adair, Cherokee, Delaware, Haskell, Hughes, Latimer and 11 more	2 hr

Nearby

Mesoscale Discussions in Oklahoma, 2020 Every mesoscale discussion in 2020

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.