Alert archive / Texas / Flash Flood Warnings in 2008

Flash Flood Warning 15, NWS Houston/Galveston, TX

September 14, 200811 counties in Texas

NWS Houston/Galveston, TX issued this flash flood warning at Sep 14, 2008, 8:36 AM CDT for 11 counties in Texas. It was in force for 3 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: Sep 14, 2008, 8:36 AM CDT (13:36 UTC)
Expired: Sep 14, 2008, 11:30 AM CDT
In force: 3 hr
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

Counties Austin County, TX, Brazoria County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Harris County, TX, Jackson County, TX, Liberty County, TX, Matagorda County, TX, Montgomery County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 50 km from the middle of the area, began a volume at 13:37 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, 1.6 hours before the alert went out and 239 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: 2965 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 456 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 20 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 flash 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 flash flood warning went out at Sep 14, 3:32 AM CDT, 5 hours 4 minutes earlier.

Area forecast discussion, Sep 14, 3:32 AM CDT, 5 hours 4 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
332 AM CDT SUN SEP 14 2008

.DISCUSSION...
STILL RECOVERING FROM THE AFFECTS OF IKE. THE OFFICE ITSELF HELD
UP VERY WELL. DURING THE PAST COUPLE OF HOURS...THE BUILDING WENT
FROM BACKUP TO COMMERCIAL POWER.

THE REMNANTS OF IKE WERE PUSHING INTO SOUTHWESTER ARKANSAS EARLY
THIS MORNING. BEHIND THE STORM...A COLD FRONT WILL PUSH ACROSS SE
TX AND BRING SCATTERED TO LIKELY COVERAGE ALONG AND AHEAD OF THE
FRONT. THIS COLD FRONT WILL PUSH ACROSS SE TX TODAY AND OFF THE
COAST TONIGHT. GENERALLY WENT WITH THE GFS BUT DID KEEP ISOLATED
POPS ALONG THE COASTAL AREAS EARLY MONDAY.

A COMBINATION OF LOW GRIDDED FLASH FLOOD VALUES AND PW/S BETWEEN
2 AND 2.5 INCHES LEADING TOWARD LIKELY RAIN COVERAGE MEANS THAT
THERE IS A CHANCE FOR RAINFALL EXCEEDING THE FLASH FLOOD GUIDANCE.
WILL KEEP THE FLASH FLOOD WATCH IN PLACE THROUGH THIS AFTERNOON.

THE REMAINDER OF THE WEEK LOOKS DRIER. COOLER CONDITIONS BEHIND
THE FRONTAL SYSTEM WILL SLOWLY WARM THROUGH THE END OF THE PERIOD.

40

&&

.AVIATION...
WILL CARRY VCSH/VCTS AT OUR NORTHERN TAF SITES (IAH...CLL...CXO...
UTS) THIS MORNING AND AT OUR SOUTHERN TAF SITES (HOU...SGR...
LBX...GLS) THIS AFTERNOON AND EARLY THIS EVENING IN ASSOCIATION
WITH A COLD FRONT MOVING INTO SOUTHEAST TEXAS DURING THE DAY.
WINDS WILL SHIFT TO THE NORTH AFTER THE FRONTAL PASSAGE WITH RAINS
COMING TO AN END. 42

&&

.MARINE...
WE WILL HAVE A COMBINATION OF CAUTION AND ADVISORY FLAGS FOR OUR
WATERS TODAY AS WAVE HEIGHTS CONTINUE TO SLOWLY COME DOWN. AN
OFFSHORE FLOW WILL DEVELOP AND STRENGTHEN TONIGHT AS A COLD FRONT
MOVES OFF THE COAST. WILL UPDATE OUR COASTAL HAZARD MESSAGE FOR
THE ELEVATED TIDE LEVELS THAT ARE SLOWLY COMING DOWN. 42

&&

.CLIMATE...
A LOT OF YESTERDAYS CLIMATE DATA IS INCORRECT OR MISSING. WE WILL
WORK ON FIXING THE INFORMATION DURING THE DAY TODAY. 42

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      90  64  84  58  83 /  40  10  10  10  10
HOUSTON (IAH)              88  67  83  60  83 /  60  30  10  10  10
GALVESTON (GLS)            85  72  82  68  81 /  60  60  20  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
     BRAZORIA...CHAMBERS...FORT BEND...GALVESTON...HARRIS...
     HOUSTON...LIBERTY...MONTGOMERY...POLK...SAN JACINTO...
     TRINITY...WALKER...WALLER.

GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS
     AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
     THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
     ISLAND TO FREEPORT OUT 20 NM.

     SMALL CRAFT ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR THE
     FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
     CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
     FREEPORT 20 TO 60 NM.

     SMALL CRAFT SHOULD EXERCISE CAUTION FROM 1 PM CDT THIS AFTERNOON
     THROUGH THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM
     FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
     WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM.

&&

DISCUSSION...40
AVIATION/MARINE/CLIMATE...42

Hazardous weather outlook, Sep 14, 6:11 AM CDT, 2 hours 25 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, Sep 14, 5:44 AM CDT, 2 hours 52 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>

Special weather statement, Sep 14, 7:56 AM 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
Sep 13, 11:32 PM CDT	Severe Thunderstorm Warning	HGX	Austin, Colorado, Washington	43 min
Sep 14, 5:05 AM CDT	Areal Flood Advisory	HGX	Harris, Liberty, Montgomery	55 min
Sep 14, 5:30 AM CDT	Flash Flood Warning	HGX	Harris, Liberty	3 hr
Sep 14, 7:35 AM CDT	Flash Flood Warning	HGX	Austin, Colorado, Fort Bend, Harris, Jackson, Wharton	55 min
Sep 14, 7:37 AM CDT	River Flood Warning	HGX	Harris	12 hr
Sep 14, 7:37 AM CDT	River Flood Warning	HGX	Harris	23 hr
Sep 14, 8:20 AM CDT	Special Marine Warning	HGX		55 min
Sep 14, 8:37 AM CDT	River Flood Warning	HGX	Harris	11 hr
Sep 14, 9:12 AM CDT	Special Marine Warning	HGX		93 min

Nearby

Flash Flood Warnings in Texas, 2008 Every flash flood warning in 2008

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.