Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 334

April 17, 201518 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2015, 10:26 AM CDT for 18 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 17, 2015, 10:26 AM CDT (15:26 UTC)
Expired: Apr 17, 2015, 12:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Bandera County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Comal County, TX, Edwards County, TX, Gillespie County, TX, Hays County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Llano County, TX, Mason County, TX, Medina County, TX, Real County, TX, Sutton County, TX, Uvalde County, TX

The radar

The Laughlin AFB radar (KDFX), 91 km from the middle of the area, began a volume at 15:27 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.

Severe Thunderstorm Watch 67Apr 17, 11:50 AM CDT

The nearest sounding before it

Del Rio, TX (KDLF), launched 12:00Z, 3.4 hours before the alert went out and 124 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: 2878 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 470 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 165 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 7.7

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 16, 7:08 PM CDT	Mesoscale Discussion	SPC	Collingsworth, Wheeler	2 hr
Apr 16, 7:16 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Briscoe, Brown, Callahan, Childress and 41 more	89 min
Apr 16, 7:44 PM CDT	Mesoscale Discussion	SPC	Dallam, Hansford, Sherman	61 min
Apr 16, 8:20 PM CDT	Mesoscale Discussion	SPC	Brazoria, Chambers, Colorado, Fort Bend, Galveston, Harris and 2 more	85 min
Apr 16, 8:36 PM CDT	Tornado Watch	SPC	Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 10 more	3 hr
Apr 16, 10:20 PM CDT	Mesoscale Discussion	SPC	Andrews, Armstrong, Borden, Briscoe, Carson, Castro and 32 more	2 hr
Apr 16, 11:33 PM CDT	Mesoscale Discussion	SPC	Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 6 more	87 min
Apr 16, 11:59 PM CDT	Severe Thunderstorm Watch	SPC	Collingsworth, Donley, Gray, Hemphill, Roberts, Wheeler	5 hr
Apr 17, 1:10 AM CDT	Mesoscale Discussion	SPC	Borden, Childress, Cottle, Crosby, Dawson, Dickens and 13 more	95 min
Apr 17, 2:02 AM CDT	Mesoscale Discussion	SPC	Collingsworth, Donley, Gray, Hemphill, Lipscomb, Roberts and 1 more	88 min
Apr 17, 4:43 AM CDT	Mesoscale Discussion	SPC	Hardeman	62 min
Apr 17, 10:55 AM CDT	Mesoscale Discussion	SPC	Baylor, Brown, Callahan, Coke, Coleman, Concho and 15 more	2 hr
Apr 17, 11:53 AM CDT	Severe Thunderstorm Watch	SPC	Archer, Atascosa, Bandera, Baylor, Bee, Bell and 73 more	7 hr
Apr 17, 1:31 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bee, Calhoun, DeWitt, Dimmit, Frio and 12 more	89 min
Apr 17, 3:06 PM CDT	Mesoscale Discussion	SPC	Briscoe, Carson, Childress, Collingsworth, Donley, Gray and 8 more	84 min
Apr 17, 3:22 PM CDT	Mesoscale Discussion	SPC	Aransas, Bee, Brazoria, Calhoun, Colorado, DeWitt and 11 more	113 min
Apr 17, 3:30 PM CDT	Severe Thunderstorm Watch	SPC	Aransas, Atascosa, Austin, Bastrop, Brazoria, Brazos and 30 more	6 hr
Apr 17, 5:02 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Bosque, Brown, Callahan, Clay and 28 more	88 min
Apr 17, 5:41 PM CDT	Mesoscale Discussion	SPC	Aransas, Atascosa, Bee, Brazoria, Brooks, Calhoun and 26 more	94 min
Apr 17, 6:57 PM CDT	Tornado Watch	SPC	Aransas, Bee, Brooks, Calhoun, Duval, Goliad and 16 more	5 hr

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.