Alert archive / Texas / Severe Thunderstorm Warnings in 2006

Severe Thunderstorm Warning 15, NWS Houston/Galveston, TX

April 20, 2006Grimes County, Madison County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Apr 20, 2006, 9:30 PM CDT for Grimes County, Madison County, Texas. It was in force for 60 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: Apr 20, 2006, 9:30 PM CDT (02:30 UTC)
Expired: Apr 20, 2006, 10:30 PM CDT
In force: 60 min
Issued by: NWS Houston/Galveston, TX
Area: Counties, with a storm outline in the text

Counties Grimes County, TX, Madison County, TX

The radar

The Ft Hood radar (KGRK), 136 km from the middle of the area, began a volume at 02:32 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 20, 6:34 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.5 hours before the alert went out and 263 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: 10 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 1007 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 330 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Apr 20, 9:25 PM CDT, 5 minutes earlier.

Area forecast discussion, Apr 20, 9:25 PM CDT, 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>

Hazardous weather outlook, Apr 20, 8:28 PM CDT, 1 hour 2 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>

In the hours before

Local storm report, Apr 20, 8:35 PM CDT, 55 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>

Local storm report, Apr 20, 8:50 PM CDT, 40 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
Apr 20, 7:20 PM CDT	Tornado Warning	HGX	Grimes, Waller	40 min
Apr 20, 7:28 PM CDT	Tornado Warning	HGX	Washington	21 min
Apr 20, 9:04 PM CDT	Severe Thunderstorm Warning	HGX	Brazos, Burleson	56 min
Apr 20, 9:56 PM CDT	Severe Thunderstorm Warning	HGX	Houston, Montgomery, Walker	64 min
Apr 20, 10:41 PM CDT	Severe Thunderstorm Warning	HGX	San Jacinto, Trinity	46 min
Apr 21, 4:44 AM CDT	Severe Thunderstorm Warning	HGX	Austin, Colorado	61 min
Apr 21, 5:23 AM CDT	Special Marine Warning	HGX		2 hr
Apr 21, 5:24 AM CDT	Severe Thunderstorm Warning	HGX	Fort Bend, Jackson, Wharton	66 min
Apr 21, 5:44 AM CDT	Severe Thunderstorm Warning	HGX	Harris	61 min
Apr 21, 6:01 AM CDT	Tornado Warning	HGX	Fort Bend	29 min
Apr 21, 6:07 AM CDT	Severe Thunderstorm Warning	HGX	San Jacinto	23 min
Apr 21, 6:15 AM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Matagorda	60 min
Apr 21, 6:29 AM CDT	Severe Thunderstorm Warning	HGX	Fort Bend	31 min
Apr 21, 6:36 AM CDT	Severe Thunderstorm Warning	HGX	Polk	39 min
Apr 21, 6:42 AM CDT	Severe Thunderstorm Warning	HGX	Harris	48 min
Apr 21, 6:44 AM CDT	Special Marine Warning	HGX		2 hr
Apr 21, 6:55 AM CDT	Severe Thunderstorm Warning	HGX	Galveston	50 min
Apr 21, 7:18 AM CDT	Severe Thunderstorm Warning	HGX	Chambers	42 min
Apr 21, 7:23 AM CDT	Severe Thunderstorm Warning	HGX	Liberty	37 min
Apr 21, 8:47 AM CDT	Special Marine Warning	HGX		43 min

Nearby

Severe Thunderstorm Warnings in Texas, 2006 Every severe thunderstorm warning in 2006

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.