Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 1571

August 26, 2017Galveston County, Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 26, 2017, 1:17 AM CDT for Galveston County, Texas. It was in force for 28 min.

The area

The outline as issued.

The facts

Issued: Aug 26, 2017, 1:17 AM CDT (06:17 UTC)
Expired: Aug 26, 2017, 1:45 AM CDT
In force: 28 min
Issued by: the Storm Prediction Center

County Galveston County, TX

The radar

The Houston radar (KHGX), 31 km from the middle of the area, began a volume at 06:19 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 467Aug 26, 1:45 AM CDT

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 6.3 hours before the alert went out and 182 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: 275 J/kg
Mixed-layer CIN: -69 J/kg
Mixed-layer LCL: 739 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 253 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.3

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
Aug 25, 7:36 PM CDT	Mesoscale Discussion	SPC	Aransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 8 more	114 min
Aug 25, 11:30 PM CDT	Mesoscale Discussion	SPC	Aransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 8 more	2 hr
Aug 26, 1:48 AM CDT	Tornado Watch	SPC	Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more	11 hr
Aug 26, 6:49 AM CDT	Mesoscale Discussion	SPC	Chambers, Galveston, Harris	116 min
Aug 26, 11:20 AM CDT	Mesoscale Discussion	SPC	Austin, Bastrop, Brazoria, Brazos, Burleson, Chambers and 25 more	115 min
Aug 26, 12:50 PM CDT	Tornado Watch	SPC	Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 13 more	13 hr
Aug 26, 3:44 PM CDT	Mesoscale Discussion	SPC	Austin, Brazoria, Brazos, Chambers, Colorado, Fort Bend and 19 more	61 min
Aug 26, 6:00 PM CDT	Mesoscale Discussion	SPC	Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 17 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2017 Every mesoscale discussion in 2017

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.