Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 669

May 1, 20034 states

The Storm Prediction Center issued this mesoscale discussion at May 1, 2003, 6:02 PM EDT for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: May 1, 2003, 6:02 PM EDT (22:02 UTC)
Expired: May 1, 2003, 9:00 PM EDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 62 counties

Allegany County, MD, Baltimore County, MD, Carroll County, MD, Frederick County, MD, Garrett County, MD, Howard County, MD, Montgomery County, MD, Washington County, MD, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Mifflin County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, York County, PA, Arlington County, VA, Augusta County, 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 Staunton, 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, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah 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 Sterling radar (KLWX), 70 km from the middle of the area, began a volume at 22:08 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, 10.0 hours before the alert went out and 77 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: 25 J/kg
Mixed-layer CIN: -259 J/kg
Mixed-layer LCL: 681 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 160 m²/s²
0-3 km storm-relative helicity: 151 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 1, 12:41 PM EDT	Mesoscale Discussion	SPC	Allegheny, Armstrong, Beaver, Bradford, Butler, Cameron and 16 more	3 hr
May 1, 1:30 PM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Armstrong, Beaver, Butler, Cameron, Clarion and 15 more	6 hr
May 1, 4:10 PM EDT	Mesoscale Discussion	SPC	Allegheny, Armstrong, Beaver, Butler, Cameron, Clarion and 13 more	95 min
May 1, 11:22 AM EDT	Mesoscale Discussion	SPC	Alleghany, Amherst, Bath, Bedford, Bland, Botetourt and 29 more	113 min
May 1, 1:50 PM EDT	Severe Thunderstorm Watch	SPC	Brooke, Ohio	5 hr

Nearby

Mesoscale Discussions in Virginia, 2003 Mesoscale Discussions in Pennsylvania, 2003 Mesoscale Discussions in West Virginia, 2003 Every mesoscale discussion in 2003

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.