Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 1439

July 5, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2009, 4:18 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 5, 2009, 4:18 AM CDT (09:18 UTC)
Expired: Jul 5, 2009, 6:45 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 26 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Winston County, AL, Chattooga County, GA, Floyd County, GA, Itawamba County, MS, Franklin County, TN, Giles County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marshall County, TN, Moore County, TN

The radar

The Northeast Alabama radar (KHTX), 88 km from the middle of the area, began a volume at 09:18 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

Nashville Metro, TN (KBNA), launched 00:00Z, 9.3 hours before the alert went out and 176 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: 238 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 1204 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 297 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

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
Jul 5, 12:40 PM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bullock, Butler, Chambers, Chilton and 17 more	65 min
Jul 5, 1:06 PM CDT	Severe Thunderstorm Watch	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 28 more	8 hr
Jul 5, 3:36 PM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bibb, Bullock, Chilton, Crenshaw and 15 more	54 min
Jul 5, 5:10 PM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 23 more	65 min
Jul 5, 6:12 PM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bullock, Butler, Chambers, Chilton and 30 more	63 min
Jul 4, 8:02 PM CDT	Mesoscale Discussion	SPC	Bedford, Benton, Bledsoe, Cannon, Carroll, Cheatham and 48 more	28 min
Jul 5, 1:01 AM CDT	Mesoscale Discussion	SPC	Bedford, Coffee, Decatur, Franklin, Giles, Henderson and 8 more	3 hr
Jul 5, 1:21 PM CDT	Mesoscale Discussion	SPC	Bedford, Benton, Cannon, Cheatham, Clay, Davidson and 28 more	54 min

Nearby

Mesoscale Discussions in Alabama, 2009 Mesoscale Discussions in Tennessee, 2009 Mesoscale Discussions in Georgia, 2009 Every mesoscale discussion in 2009

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.