Alert archive / Texas / Areal Flood Warnings in 2021

Areal Flood Warning 33, NWS Houston/Galveston, TX

October 1, 20215 counties in Texas

NWS Houston/Galveston, TX issued this areal flood warning at Oct 1, 2021, 12:02 PM CDT for 5 counties in Texas. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 1, 2021, 12:02 PM CDT (17:02 UTC)
Expired: Oct 1, 2021, 2:22 PM CDT
In force: 2 hr
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

Counties Austin County, TX, Grimes County, TX, Harris County, TX, Waller County, TX, Washington County, TX

The radar

The Houston radar (KHGX), 114 km from the middle of the area, began a volume at 17:01 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, 5.0 hours before the alert went out and 270 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: 1808 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 585 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 57 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood 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 areal flood warning went out at Oct 1, 11:23 AM CDT, 39 minutes earlier.

Area forecast discussion, Oct 1, 11:23 AM CDT, 39 minutes before

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In the hours before

Local storm report, Oct 1, 8:54 AM CDT, 3 hours 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
854 AM CDT FRI OCT 1 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0845 AM     FLASH FLOOD      4 WSW ONALASKA          30.80N 95.16W
10/01/2021                   SAN JACINTO        TX   LAW ENFORCEMENT

            REPORTS OF ROADS BECOMING IMPASSABLE IN THE
            HOLIDAY VILLAGE AREA OFF OF US HIGHWAY 190.

&&

Local storm report, Oct 1, 9:18 AM CDT, 2 hours 44 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
918 AM CDT FRI OCT 1 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 AM     FLASH FLOOD      3 ENE HEMPSTEAD         30.11N 96.03W
10/01/2021                   WALLER             TX   DEPT OF HIGHWAYS

            FM 1488 AT WYATT CHAPEL RD HAS WATER UP TO
            THE GUARDRAIL AND IS NOT PASSABLE.

&&

CB

Local storm report, Oct 1, 11:40 AM CDT, 22 minutes before

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    <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.
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        Please try again in a few minutes.
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Local storm report, Oct 1, 11:44 AM CDT, 18 minutes before

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<head>
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  <title>Service Notice</title>
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</head>
<body>
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    <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.
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      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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Local storm report, Oct 1, 11:46 AM CDT, 16 minutes before

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<head>
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  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
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</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.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 1, 5:37 AM CDT	Areal Flood Advisory	HGX	Chambers, Harris, Liberty	27 min
Oct 1, 5:57 AM CDT	Areal Flood Advisory	HGX	Austin, Grimes, Waller, Washington	2 hr
Oct 1, 6:04 AM CDT	Flash Flood Warning	HGX	Harris	3 hr
Oct 1, 6:52 AM CDT	Areal Flood Advisory	HGX	Harris	113 min
Oct 1, 7:23 AM CDT	Areal Flood Advisory	HGX	Fort Bend, Harris, Waller	67 min
Oct 1, 7:40 AM CDT	Areal Flood Advisory	HGX	Austin, Grimes, Harris, Waller, Washington	99 min
Oct 1, 8:29 AM CDT	Flash Flood Warning	HGX	Fort Bend, Harris, Waller	3 hr
Oct 1, 8:34 AM CDT	Areal Flood Advisory	HGX	Harris, Montgomery	65 min
Oct 1, 8:38 AM CDT	Flash Flood Warning	HGX	Polk, San Jacinto, Trinity	3 hr
Oct 1, 9:01 AM CDT	Areal Flood Warning	HGX	Chambers, Harris, Liberty	5 hr
Oct 1, 9:19 AM CDT	Flash Flood Warning	HGX	Grimes, Waller, Washington	3 hr
Oct 1, 9:25 AM CDT	Areal Flood Advisory	HGX	Fort Bend	3 hr
Oct 1, 9:37 AM CDT	Areal Flood Advisory	HGX	Harris	3 hr
Oct 1, 10:57 AM CDT	Areal Flood Warning	HGX	Fort Bend, Harris, Waller	3 hr
Oct 1, 11:01 AM CDT	Areal Flood Advisory	HGX	Liberty, San Jacinto	3 hr
Oct 1, 11:08 AM CDT	River Flood Warning	HGX	Harris	4 hr
Oct 1, 11:54 AM CDT	Areal Flood Advisory	HGX	Polk, San Jacinto, Trinity	2 hr
Oct 1, 12:42 PM CDT	Areal Flood Advisory	HGX	Fort Bend, Harris, Montgomery	78 min

Nearby

Areal Flood Warnings in Texas, 2021 Every areal flood warning in 2021

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.