Alert archive / Texas / Mesoscale Discussions in 2019

Mesoscale Discussion 480

April 30, 201934 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2019, 1:53 PM CDT for 34 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 30, 2019, 1:53 PM CDT (18:53 UTC)
Expired: Apr 30, 2019, 4:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 34 counties

Archer County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Coryell County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Grayson County, TX, Hamilton County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Lampasas County, TX, McCulloch County, TX, Mills County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, San Saba County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Wise County, TX, Young County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 78 km from the middle of the area, began a volume at 18:56 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

Fort Worth, TX (KFWD), launched 12:00Z, 6.9 hours before the alert went out and 84 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: 1278 J/kg
Mixed-layer CIN: -54 J/kg
Mixed-layer LCL: 701 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 237 m²/s²
0-3 km storm-relative helicity: 356 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 8.5

Open this sounding in Storm Lab

The text

As transmitted.

<!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 29, 7:01 PM CDT	Severe Thunderstorm Watch	SPC	Andrews, Borden, Dawson, Ector, Gaines, Howard and 7 more	3 hr
Apr 29, 9:35 PM CDT	Mesoscale Discussion	SPC	Ector, Loving, Winkler	115 min
Apr 30, 2:06 PM CDT	Mesoscale Discussion	SPC	Bailey, Borden, Cochran, Crosby, Dawson, Dickens and 17 more	2 hr
Apr 30, 2:19 PM CDT	Tornado Watch	SPC	Archer, Baylor, Bosque, Clay, Collin, Comanche and 24 more	9 hr
Apr 30, 2:56 PM CDT	Mesoscale Discussion	SPC	Baylor, Wilbarger	2 hr
Apr 30, 4:26 PM CDT	Severe Thunderstorm Watch	SPC	Borden, Briscoe, Brown, Callahan, Childress, Coke and 44 more	8 hr
Apr 30, 5:21 PM CDT	Mesoscale Discussion	SPC	Archer, Bosque, Clay, Collin, Comanche, Cooke and 19 more	84 min
Apr 30, 6:47 PM CDT	Mesoscale Discussion	SPC	Borden, Coke, Cottle, Crane, Crockett, Crosby and 36 more	118 min

Nearby

Mesoscale Discussions in Texas, 2019 Every mesoscale discussion in 2019

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.