Alert archive / Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 887

May 23, 20114 states

The Storm Prediction Center issued this mesoscale discussion at May 23, 2011, 10:33 AM EDT for 4 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: May 23, 2011, 10:33 AM EDT (14:33 UTC)
Expired: May 23, 2011, 12:00 PM EDT
In force: 87 min
Issued by: the Storm Prediction Center

All 80 counties

Allegany County, MD, Baltimore County, MD, Carroll County, MD, City of Baltimore, MD, Frederick County, MD, Garrett County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Adams County, PA, Armstrong County, PA, Bedford County, PA, Blair County, PA, Cambria County, PA, Cameron County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Cumberland County, PA, Elk County, PA, Fayette County, PA, Forest County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, McKean County, PA, Mifflin County, PA, Perry County, PA, Potter County, PA, Snyder County, PA, Somerset County, PA, Westmoreland County, PA, Albemarle County, VA, Arlington County, VA, Augusta County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV, Preston County, WV, Randolph County, WV, Tucker County, WV

The radar

The State College radar (KCCX), 85 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 338May 23, 10:50 AM EDT

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 2.6 hours before the alert went out and 180 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: 22 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 581 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 152 m²/s²
0-3 km storm-relative helicity: 177 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 23, 10:48 AM EDT	Severe Thunderstorm Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more	9 hr
May 23, 2:33 PM EDT	Mesoscale Discussion	SPC	Allegany, Carroll, Charles, Frederick, Howard, Montgomery and 1 more	87 min
May 23, 4:40 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles and 9 more	95 min
May 23, 8:25 AM EDT	Mesoscale Discussion	SPC	Crawford, Erie	65 min
May 22, 9:02 PM EDT	Mesoscale Discussion	SPC	Carroll, Craig, Floyd, Giles, Montgomery, Patrick and 5 more	58 min
May 23, 3:16 PM EDT	Severe Thunderstorm Watch	SPC	Alleghany, Amelia, Amherst, Appomattox, Bath, Bedford and 78 more	7 hr
May 23, 7:02 PM EDT	Mesoscale Discussion	SPC	Amelia, Appomattox, Brunswick, Buckingham, Campbell, Charles City and 40 more	58 min
May 23, 7:20 PM EDT	Mesoscale Discussion	SPC	Boone, Brooke, Cabell, Calhoun, Doddridge, Jackson and 16 more	85 min

Nearby

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