Alert archive / Virginia / Mesoscale Discussions in 2015

Mesoscale Discussion 1094

June 20, 20154 states

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2015, 10:14 PM EDT for 4 states. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Jun 20, 2015, 10:14 PM EDT (02:14 UTC)
Expired: Jun 20, 2015, 11:15 PM EDT
In force: 61 min
Issued by: the Storm Prediction Center

All 55 counties

Kent County, DE, Sussex County, DE, Calvert County, MD, Caroline County, MD, Dorchester County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Bertie County, NC, Camden County, NC, Chowan County, NC, Edgecombe County, NC, Gates County, NC, Halifax County, NC, Hertford County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Washington County, NC, Accomack County, VA, Charles City County, VA, City of Chesapeake, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Gloucester County, VA, Greensville County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 83 km from the middle of the area, began a volume at 02:17 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.2 hours before the alert went out and 95 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: 261 J/kg
Mixed-layer CIN: -134 J/kg
Mixed-layer LCL: 1179 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 75 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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
Jun 20, 8:37 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	53 min
Jun 20, 8:56 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	4 hr
Jun 21, 2:52 PM EDT	Mesoscale Discussion	SPC	Buchanan, Dickenson, Lee, Russell, Tazewell, Wise and 1 more	113 min
Jun 21, 3:23 PM EDT	Severe Thunderstorm Watch	SPC	Alleghany, Bath, Bedford, Bland, Botetourt, Buchanan and 36 more	5 hr

Nearby

Mesoscale Discussions in Virginia, 2015 Mesoscale Discussions in North Carolina, 2015 Mesoscale Discussions in Maryland, 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; radar from the NEXRAD Level II archive.