Alert archive / Virginia / Mesoscale Discussions in 2008

Mesoscale Discussion 827

May 8, 200811 counties in North Carolina; 44 counties in Virginia; 6 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 8, 2008, 6:12 PM EDT for 11 counties in North Carolina; 44 counties in Virginia; 6 counties in West Virginia. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: May 8, 2008, 6:12 PM EDT (22:12 UTC)
Expired: May 8, 2008, 7:15 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center

All 61 counties

Alamance County, NC, Alleghany County, NC, Caswell County, NC, Forsyth County, NC, Guilford County, NC, Person County, NC, Randolph County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Yadkin County, NC, Albemarle County, VA, Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Danville, VA, City of Galax, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Greene County, VA, Halifax County, VA, Henry County, VA, Highland County, VA, Montgomery County, VA, Nelson County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Wythe County, VA, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Pendleton County, WV, Pocahontas County, WV, Summers County, WV

The radar

The Roanoke radar (KFCX), 50 km from the middle of the area, began a volume at 22:14 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.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 10.2 hours before the alert went out and 23 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: 29 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 977 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 182 m²/s²
0-3 km storm-relative helicity: 200 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 8, 2:22 PM EDT	Mesoscale Discussion	SPC	Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 10 more	83 min
May 8, 6:48 PM EDT	Tornado Watch	SPC	Alleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more	9 hr
May 8, 7:20 PM EDT	Tornado Watch	SPC	Alamance, Alexander, Anson, Avery, Buncombe, Burke and 29 more	8 hr

Nearby

Mesoscale Discussions in Virginia, 2008 Mesoscale Discussions in North Carolina, 2008 Mesoscale Discussions in West Virginia, 2008 Every mesoscale discussion in 2008

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.