Alert archive / Texas / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 141, NWS Houston/Galveston, TX

November 21, 2007Polk County, Trinity County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Nov 21, 2007, 1:44 PM CST for Polk County, Trinity County, Texas. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Nov 21, 2007, 1:44 PM CST (19:44 UTC)
Expired: Nov 21, 2007, 2:11 PM CST
In force: 27 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon

Counties Polk County, TX, Trinity County, TX

The radar

The Houston radar (KHGX), 164 km from the middle of the area, began a volume at 19:47 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.7 hours before the alert went out and 194 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: 1033 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 575 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at Nov 21, 11:37 AM CST, 2 hours 7 minutes earlier.

Area forecast discussion, Nov 21, 11:37 AM CST, 2 hours 7 minutes before

<!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>

Hazardous weather outlook, Nov 21, 5:39 AM CST, 8 hours 5 minutes before

<!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>

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 21, 3:37 PM CST	Severe Thunderstorm Warning	HGX	Brazos, Grimes	29 min
Nov 21, 4:26 PM CST	Severe Thunderstorm Warning	HGX	Liberty	34 min
Nov 21, 4:53 PM CST	Severe Thunderstorm Warning	HGX	Grimes, Montgomery	14 min
Nov 21, 5:46 PM CST	Severe Thunderstorm Warning	HGX	Harris	29 min

Nearby

Severe Thunderstorm Warnings in Texas, 2007 Every severe thunderstorm warning in 2007

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.