Alert archive / Alabama / Mesoscale Discussions in 2008

Mesoscale Discussion 822

May 8, 200813 counties in Alabama; 4 counties in Georgia; 7 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 8, 2008, 12:37 PM CDT for 13 counties in Alabama; 4 counties in Georgia; 7 counties in Tennessee. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: May 8, 2008, 12:37 PM CDT (17:37 UTC)
Expired: May 8, 2008, 2:00 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center

All 24 counties

Blount County, AL, Cherokee County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Walker County, GA, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Lincoln County, TN, Marion County, TN, Moore County, TN, Sequatchie County, TN

The radar

The Northeast Alabama radar (KHTX), 59 km from the middle of the area, began a volume at 17:39 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 278May 8, 12:40 PM CDT

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 5.6 hours before the alert went out and 148 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: 212 J/kg
Mixed-layer CIN: -132 J/kg
Mixed-layer LCL: 567 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 193 m²/s²
0-3 km storm-relative helicity: 216 m²/s²
Significant tornado parameter: 0.1
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
May 8, 7:48 AM CDT	Mesoscale Discussion	SPC	Colbert, Fayette, Franklin, Lamar, Lawrence, Marion and 3 more	87 min
May 8, 8:04 AM CDT	Tornado Watch	SPC	Colbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 9 more	6 hr
May 8, 10:07 AM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 33 more	83 min
May 8, 12:13 PM CDT	Mesoscale Discussion	SPC	Bibb, Fayette, Greene, Hale, Jefferson, Perry and 4 more	92 min
May 8, 12:40 PM CDT	Tornado Watch	SPC	Bibb, Blount, Calhoun, Cherokee, Chilton, Choctaw and 29 more	5 hr
May 8, 3:13 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Calhoun, Chambers, Cherokee, Chilton and 17 more	2 hr
May 8, 1:22 PM CDT	Mesoscale Discussion	SPC	Carter, Cocke, Greene, Hamblen, Hawkins, Johnson and 4 more	83 min

Nearby

Mesoscale Discussions in Alabama, 2008 Mesoscale Discussions in Tennessee, 2008 Mesoscale Discussions in Georgia, 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.