Alert archive / Virginia / Mesoscale Discussions in 2015

Mesoscale Discussion 1209

June 27, 20157 counties in Maryland; 60 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 27, 2015, 12:56 PM EDT for 7 counties in Maryland; 60 counties in Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jun 27, 2015, 12:56 PM EDT (16:56 UTC)
Expired: Jun 27, 2015, 3:30 PM EDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 67 counties

Calvert County, MD, Charles County, MD, Dorchester County, MD, Prince George's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Accomack County, VA, Amelia County, VA, Arlington County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Fairfax, VA, City of Falls Church, VA, City of Franklin, VA, City of Fredericksburg, VA, City of Hampton, VA, City of Hopewell, VA, City of Manassas, VA, City of Manassas Park, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Lunenburg County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince George County, VA, Prince William County, VA, Richmond County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 69 km from the middle of the area, began a volume at 16:58 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.

Tornado Watch 364Jun 27, 1:55 PM EDT

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 4.9 hours before the alert went out and 123 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: 16 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 629 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: 79 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
Jun 27, 1:54 PM EDT	Tornado Watch	SPC	Calvert, Caroline, Charles, Dorchester, Kent, Queen Anne's and 5 more	6 hr
Jun 27, 4:39 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Calvert, Caroline, Charles, Dorchester, Prince George's and 6 more	96 min
Jun 27, 6:23 PM EDT	Mesoscale Discussion	SPC	Charles, Saint Mary's	2 hr
Jun 26, 8:05 PM EDT	Mesoscale Discussion	SPC	Bath, Dickenson, Highland, Lee, Russell, Scott and 3 more	85 min
Jun 26, 9:58 PM EDT	Mesoscale Discussion	SPC	Alleghany, Augusta, Bath, Highland, Rockbridge, Rockingham and 4 more	62 min
Jun 27, 2:06 PM EDT	Mesoscale Discussion	SPC	Amherst, Bedford, Botetourt, Campbell, Carroll, Charlotte and 15 more	2 hr

Nearby

Mesoscale Discussions in Virginia, 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.