Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 537

May 7, 201513 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2015, 5:41 PM CDT for 13 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: May 7, 2015, 5:41 PM CDT (22:41 UTC)
Expired: May 7, 2015, 7:15 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Brown County, TX, Callahan County, TX, Comanche County, TX, Eastland County, TX, Erath County, TX, Fisher County, TX, Haskell County, TX, Jones County, TX, Kent County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Stonewall County, TX

The radar

The Dyess AFB radar (KDYX), 18 km from the middle of the area, began a volume at 22:41 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 12:00Z, 10.7 hours before the alert went out and 202 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: 656 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 632 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 191 m²/s²
0-3 km storm-relative helicity: 284 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 5.2

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 6, 8:08 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Foard, Hardeman, Haskell and 10 more	67 min
May 6, 8:51 PM CDT	Tornado Watch	SPC	Archer, Baylor, Clay, Foard, Hardeman, Haskell and 7 more	5 hr
May 6, 10:53 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Foard, Hardeman, Haskell and 7 more	2 hr
May 7, 1:16 AM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Collin, Cooke, Denton and 7 more	4 hr
May 7, 4:24 AM CDT	Mesoscale Discussion	SPC	Collin, Cooke, Grayson	66 min
May 7, 10:20 AM CDT	Mesoscale Discussion	SPC	Archer, Armstrong, Baylor, Briscoe, Childress, Clay and 20 more	115 min
May 7, 12:52 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Cooke, Denton, Foard and 11 more	113 min
May 7, 1:10 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Foard, Hardeman, Knox and 2 more	7 hr
May 7, 3:51 PM CDT	Mesoscale Discussion	SPC	Collin, Cooke, Denton, Fannin, Grayson, Jack and 5 more	114 min
May 7, 4:33 PM CDT	Severe Thunderstorm Watch	SPC	Collin, Cooke, Dallas, Denton, Eastland, Ellis and 16 more	7 hr
May 7, 6:19 PM CDT	Mesoscale Discussion	SPC	Collin, Cooke, Delta, Denton, Fannin, Grayson and 5 more	86 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.