Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 497

April 29, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2016, 12:51 PM CDT for 4 states. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Apr 29, 2016, 12:51 PM CDT (17:51 UTC)
Expired: Apr 29, 2016, 2:45 PM CDT
In force: 114 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 45 counties

Bradley County, AR, Calhoun County, AR, Clark County, AR, Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Lincoln Parish, LA, Union Parish, LA, Webster Parish, LA, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 72 km from the middle of the area, began a volume at 17:51 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

Shreveport, LA (KBAD), launched 12:00Z, 5.9 hours before the alert went out and 75 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: 1756 J/kg
Mixed-layer CIN: -129 J/kg
Mixed-layer LCL: 632 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 310 m²/s²
0-3 km storm-relative helicity: 451 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 14.9

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, 1:58 AM CDT	Mesoscale Discussion	SPC	Clark, Columbia, Dallas, Garland, Hempstead, Hot Spring and 11 more	2 hr
Apr 29, 4:21 AM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Clark, Cleveland, Conway, Crawford, Dallas and 25 more	6 hr
Apr 29, 7:06 AM CDT	Mesoscale Discussion	SPC	Arkansas, Bradley, Calhoun, Clark, Cleveland, Dallas and 5 more	54 min
Apr 29, 9:46 AM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 29 more	89 min
Apr 29, 1:43 PM CDT	Tornado Watch	SPC	Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 10 more	8 hr
Apr 29, 5:42 PM CDT	Mesoscale Discussion	SPC	Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 11 more	93 min
Apr 29, 12:37 PM CDT	Mesoscale Discussion	SPC	East Carroll, Madison	83 min
Apr 28, 10:54 PM CDT	Severe Thunderstorm Watch	SPC	Beaver, Cimarron, Texas	7 hr
Apr 29, 2:59 AM CDT	Mesoscale Discussion	SPC	Beaver, Ellis, Harper	91 min
Apr 29, 4:54 AM CDT	Mesoscale Discussion	SPC	Harmon	66 min
Apr 29, 1:40 PM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Carter, Cleveland, Coal, Comanche and 15 more	65 min
Apr 29, 1:57 PM CDT	Tornado Watch	SPC	Atoka, Bryan, Caddo, Canadian, Carter, Choctaw and 27 more	8 hr
Apr 29, 3:56 PM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Caddo, Carter, Cleveland, Coal and 18 more	64 min
Apr 29, 6:16 PM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 25 more	89 min
Apr 28, 7:52 PM CDT	Mesoscale Discussion	SPC	Bell, Brazos, Burleson, Burnet, Coryell, Falls and 7 more	83 min
Apr 28, 10:31 PM CDT	Mesoscale Discussion	SPC	Armstrong, Bailey, Briscoe, Carson, Castro, Childress and 30 more	89 min
Apr 29, 7:38 AM CDT	Mesoscale Discussion	SPC	Briscoe, Cottle, Crosby, Dickens, Floyd, Foard and 10 more	97 min
Apr 29, 12:52 PM CDT	Mesoscale Discussion	SPC	Bell, Blanco, Bosque, Brown, Burnet, Comanche and 22 more	113 min
Apr 29, 1:08 PM CDT	Tornado Watch	SPC	Anderson, Bell, Bosque, Collin, Comanche, Cooke and 35 more	9 hr
Apr 29, 3:34 PM CDT	Mesoscale Discussion	SPC	Bell, Bosque, Collin, Cooke, Coryell, Dallas and 31 more	86 min

Nearby

Mesoscale Discussions in Texas, 2016 Mesoscale Discussions in Arkansas, 2016 Mesoscale Discussions in Louisiana, 2016 Every mesoscale discussion in 2016

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.