Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 2275

September 28, 20046 states

The Storm Prediction Center issued this mesoscale discussion at Sep 28, 2004, 1:49 PM EDT for 6 states. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Sep 28, 2004, 1:49 PM EDT (17:49 UTC)
Expired: Sep 28, 2004, 3:45 PM EDT
In force: 116 min
Issued by: the Storm Prediction Center

All 103 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Halifax County, NC, Hertford County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA, 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, Culpeper County, 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, Louisa County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 847Sep 28, 2:25 PM EDT

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.8 hours before the alert went out and 67 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: 1005 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 483 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 93 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.1

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
Sep 28, 8:56 AM EDT	Mesoscale Discussion	SPC	Sussex	2 hr
Sep 28, 2:25 PM EDT	Tornado Watch	SPC	Kent, New Castle, Sussex	7 hr
Sep 28, 4:36 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	114 min
Sep 28, 11:25 AM EDT	Tornado Watch	SPC	Calvert, Charles, Dorchester, Saint Mary's, Somerset, Wicomico and 1 more	6 hr
Sep 27, 9:10 PM EDT	Tornado Watch	SPC	Anson, Bladen, Brunswick, Chatham, Columbus, Cumberland and 15 more	7 hr
Sep 28, 12:46 AM EDT	Mesoscale Discussion	SPC	Anson, Bladen, Brunswick, Cabarrus, Chatham, Columbus and 16 more	89 min
Sep 28, 2:59 AM EDT	Mesoscale Discussion	SPC	Chatham, Cumberland, Durham, Harnett, Johnston, Lee and 5 more	2 hr

Nearby

Mesoscale Discussions in Virginia, 2004 Mesoscale Discussions in Maryland, 2004 Mesoscale Discussions in New Jersey, 2004 Every mesoscale discussion in 2004

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.