Alert archive / Virginia / Mesoscale Discussions in 2016

Mesoscale Discussion 1399

July 25, 20165 states

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2016, 7:06 PM EDT for 5 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jul 25, 2016, 7:06 PM EDT (23:06 UTC)
Expired: Jul 25, 2016, 8:30 PM EDT
In force: 84 min
Issued by: the Storm Prediction Center

All 53 counties

Kent County, DE, Sussex County, DE, Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Washington County, MD, Wicomico County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Loudoun County, VA, Madison County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 25 km from the middle of the area, began a volume at 23:06 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.1 hours before the alert went out and 27 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: 494 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1400 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jul 25, 3:05 PM EDT	Mesoscale Discussion	SPC	Kent, Sussex	115 min
Jul 25, 3:30 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	6 hr
Jul 25, 5:02 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	88 min
Jul 25, 12:41 PM EDT	Mesoscale Discussion	SPC	Allegany, Carroll, Frederick, Garrett, Washington	64 min
Jul 25, 12:43 PM EDT	Severe Thunderstorm Watch	SPC	Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more	7 hr
Jul 25, 3:03 PM EDT	Mesoscale Discussion	SPC	Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more	57 min
Jul 25, 4:52 PM EDT	Mesoscale Discussion	SPC	Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more	83 min

Nearby

Mesoscale Discussions in Virginia, 2016 Mesoscale Discussions in Maryland, 2016 Mesoscale Discussions in West Virginia, 2016 Every mesoscale discussion in 2016

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.