Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 281

April 6, 200418 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2004, 8:21 PM CDT for 18 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 6, 2004, 8:21 PM CDT (01:21 UTC)
Expired: Apr 6, 2004, 10:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Collin County, TX, Dallas County, TX, Denton County, TX, Ellis County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Navarro County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX, Van Zandt County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 21 km from the middle of the area, began a volume at 01:23 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

Fort Worth, TX (KFWD), launched 00:00Z, 1.4 hours before the alert went out and 37 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: 608 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 987 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 97 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.6

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
Apr 7, 12:58 PM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Bowie, Camp, Cass, Cherokee and 27 more	2 hr
Apr 7, 2:45 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Angelina, Brazos, Camp, Cherokee, Freestone and 22 more	5 hr
Apr 7, 3:05 PM CDT	Severe Thunderstorm Watch	SPC	Bowie, Delta, Franklin, Hopkins, Lamar, Red River and 1 more	5 hr
Apr 7, 6:08 PM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Bowie, Brazos, Camp, Cass and 35 more	67 min

Nearby

Mesoscale Discussions in Texas, 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; radar from the NEXRAD Level II archive.