Alert archive / Ohio / Mesoscale Discussions in 2011

Mesoscale Discussion 755

May 12, 201127 counties in Ohio; Greene County, Pennsylvania; 20 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 12, 2011, 10:30 AM EDT for 27 counties in Ohio; Greene County, Pennsylvania; 20 counties in West Virginia. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: May 12, 2011, 10:30 AM EDT (14:30 UTC)
Expired: May 12, 2011, 12:00 PM EDT
In force: 90 min
Issued by: the Storm Prediction Center

All 48 counties

Ashland County, OH, Belmont County, OH, Carroll County, OH, Coshocton County, OH, Crawford County, OH, Erie County, OH, Guernsey County, OH, Harrison County, OH, Holmes County, OH, Huron County, OH, Jefferson County, OH, Knox County, OH, Lorain County, OH, Medina County, OH, Monroe County, OH, Muskingum County, OH, Noble County, OH, Ottawa County, OH, Portage County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Stark County, OH, Summit County, OH, Tuscarawas County, OH, Washington County, OH, Wayne County, OH, Greene County, PA, Barbour County, WV, Braxton County, WV, Brooke County, WV, Calhoun County, WV, Doddridge County, WV, Gilmer County, WV, Harrison County, WV, Lewis County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Pleasants County, WV, Randolph County, WV, Ritchie County, WV, Taylor County, WV, Tyler County, WV, Upshur County, WV, Webster County, WV, Wetzel County, WV

The radar

The Cleveland radar (KCLE), 119 km from the middle of the area, began a volume at 14:33 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 290May 12, 11:05 AM EDT

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 2.5 hours before the alert went out and 137 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1624 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 12, 11:04 AM EDT	Severe Thunderstorm Watch	SPC	Ashland, Ashtabula, Athens, Belmont, Carroll, Columbiana and 39 more	8 hr
May 12, 3:36 PM EDT	Mesoscale Discussion	SPC	Ashland, Belmont, Carroll, Coshocton, Guernsey, Harrison and 12 more	84 min
May 12, 6:52 PM EDT	Mesoscale Discussion	SPC	Ashland, Ashtabula, Belmont, Carroll, Columbiana, Coshocton and 26 more
May 12, 4:28 PM EDT	Mesoscale Discussion	SPC	McDowell, Mercer, Monroe, Summers, Wyoming	2 hr

Nearby

Mesoscale Discussions in Ohio, 2011 Mesoscale Discussions in West Virginia, 2011 Mesoscale Discussions in Pennsylvania, 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.