Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 475

April 26, 201510 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2015, 9:29 PM CDT for 10 counties in Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Apr 26, 2015, 9:29 PM CDT (02:29 UTC)
Expired: Apr 26, 2015, 11:00 PM CDT
In force: 91 min
Issued by: the Storm Prediction Center

Counties Dallas County, TX, Ellis County, TX, Hood County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Parker County, TX, Rockwall County, TX, Tarrant County, TX, Van Zandt County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 32 km from the middle of the area, began a volume at 02:29 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 124Apr 26, 10:45 PM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.5 hours before the alert went out and 34 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: 1199 J/kg
Mixed-layer CIN: -82 J/kg
Mixed-layer LCL: 1646 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 248 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.3

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 26, 7:10 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Carson, Childress, Clay, Collingsworth and 14 more	65 min
Apr 26, 7:59 PM CDT	Severe Thunderstorm Watch	SPC	Bandera, Bexar, Blanco, Brown, Burnet, Coleman and 24 more	6 hr
Apr 26, 10:45 PM CDT	Tornado Watch	SPC	Anderson, Bell, Bosque, Comanche, Coryell, Ellis and 19 more	5 hr
Apr 27, 12:49 AM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Atascosa, Austin, Bastrop, Bexar and 49 more	86 min
Apr 27, 1:27 AM CDT	Tornado Watch	SPC	Angelina, Atascosa, Austin, Bastrop, Bee, Brazos and 50 more	6 hr
Apr 27, 3:42 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Cooke, Denton, Foard and 12 more	93 min
Apr 27, 4:56 AM CDT	Mesoscale Discussion	SPC	Angelina, Chambers, Hardin, Harris, Jasper, Jefferson and 13 more	2 hr
Apr 27, 5:25 AM CDT	Mesoscale Discussion	SPC	Brooks, Kenedy	95 min
Apr 27, 6:01 AM CDT	Tornado Watch	SPC	Jefferson, Orange	7 hr
Apr 27, 1:08 PM CDT	Mesoscale Discussion	SPC	Angelina, Chambers, Hardin, Jasper, Jefferson, Liberty and 9 more	97 min
Apr 27, 3:29 PM CDT	Mesoscale Discussion	SPC	Austin, Bastrop, Bell, Bosque, Brazos, Burleson and 22 more	91 min

Nearby

Mesoscale Discussions in Texas, 2015 Every mesoscale discussion in 2015

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.