Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 220, NWS Houston/Galveston, TX

December 23, 2009Houston County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Dec 23, 2009, 6:01 PM CST for Houston County, Texas. It was in force for 44 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: Dec 23, 2009, 6:01 PM CST (00:01 UTC)
Expired: Dec 23, 2009, 6:45 PM CST
In force: 44 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon

County Houston County, TX

The radar

The Shreveport radar (KSHV), 195 km from the middle of the area, began a volume at 00:03 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
Dec 23, 1:59 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 0.0 hours before the alert went out and 204 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: 649 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 446 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 329 m²/s²
0-3 km storm-relative helicity: 329 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 5.8

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 Dec 23, 5:28 PM CST, 33 minutes earlier.

Area forecast discussion, Dec 23, 5:28 PM CST, 33 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, Dec 23, 3:17 PM CST, 2 hours 44 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
317 PM CST WED DEC 23 2009

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-241400-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GALVESTON BAY-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-
MADISON-MATAGORDA-MATAGORDA BAY-MONTGOMERY-POLK-SAN JACINTO-
TRINITY-WALKER-WALLER-WASHINGTON-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM-
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM-
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM-WHARTON-
317 PM CST WED DEC 23 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

...SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT...
...WINDY ON THURSDAY...

.DAY ONE...TONIGHT

A STRONG UPPER LEVEL STORM SYSTEM AND COLD FRONT WILL BE MOVING
INTO THE AREA FROM THE WEST TONIGHT. EXPECT A SQUALL LINE TO
DEVELOP AND MOVE QUICKLY WEST TO EAST ACROSS THE AREA BETWEEN
MIDNIGHT AND 7 AM. THE PRIMARY WEATHER THREAT WILL BE STRONG
DAMAGING WINDS. HAIL AND ISOLATED TORNADOS ARE ALSO POSSIBLE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

STRONG WINDS ARE EXPECTED BEHIND THE COLD FRONT ON THURSDAY.
SUSTAINED 20 TO 30 MPH WINDS ARE POSSIBLE FROM THE WEST NORTHWEST
WITH HIGHER GUSTS POSSIBLE. A WIND ADVISORY WILL PROBABLY BE
REQUIRED FOR PORTIONS OF SOUTHEAST TEXAS. MOTORIST TRAVELING ON
NORTH TO SOUTH ORIENTED ROADS SHOULD BE CAUTIOUS. HOLIDAY
DECORATIONS IN YARDS THAT ARE NOT TIED DOWN WILL ALSO BE
SUSCEPTIBLE TO THE STRONG WINDS. OTHERWISE...NO HAZARDOUS WEATHER
IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

In the hours before

Special weather statement, Dec 23, 5:04 PM CST, 57 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
504 PM CST WED DEC 23 2009

TXZ163-177-240000-
HOUSTON-WALKER-
504 PM CST WED DEC 23 2009

...SPECIAL WEATHER STATEMENT...

AT 458 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 23 MILES SOUTH OF CROCKETT...MOVING NORTH NORTH
EAST AT 30 MPH.

THE STORM HAS A HISTORY OF ROTATION AND COULD INTENSIFY. PEA SIZE
HAIL...WINDS GREATER THAN 40 MPH...ARE POSSIBLE WITH THIS STORM.

LOCATIONS IN THE PATH OF THIS STORM INCLUDE...LOVELADY...LATEXO...
GRAPELAND AND CROCKETT.

GUSTY WINDS MAY CAUSE UNSECURED SMALL OBJECTS SUCH AS TRASH CANS TO
BLOW AROUND. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS
PASSED.

LAT...LON 3154 9549 3146 9522 3108 9541 3106 9544
      3102 9544 3091 9549 3097 9567 3100 9568
      3102 9566 3103 9566 3104 9562 3109 9565
TIME...MOT...LOC 2303Z 200DEG 30KT 3104 9555

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 23, 9:32 PM CST	Wind Advisory	HGX	Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more	30 hr
Dec 23, 9:45 PM CST	Areal Flood Advisory	HGX	Austin, Grimes, Waller, Washington	2 hr
Dec 23, 11:05 PM CST	Areal Flood Advisory	HGX	Grimes, Houston, Madison, Montgomery, San Jacinto, Trinity and 2 more	115 min
Dec 23, 11:19 PM CST	Severe Thunderstorm Warning	HGX	Houston, Trinity	21 min
Dec 24, 3:40 AM CST	Special Marine Warning	HGX		2 hr
Dec 24, 9:55 AM CST	Gale Warning	HGX		17 hr

Nearby

Severe Thunderstorm Warnings in Texas, 2009 Every severe thunderstorm warning in 2009

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.