Alert archive / Texas / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 221, NWS Houston/Galveston, TX
NWS Houston/Galveston, TX issued this severe thunderstorm warning at Dec 23, 2009, 11:19 PM CST for Houston County, Trinity County, Texas. It was in force for 21 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, 11:19 PM CST (05:19 UTC)
- Expired
- Dec 23, 2009, 11:40 PM CST
- In force
- 21 min
- Issued by
- NWS Houston/Galveston, TX
- Area
- Storm-based polygon
Counties Houston County, TX, Trinity County, TX
The radar
The Houston radar (KHGX), 193 km from the middle of the area, began a volume at 05:22 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, 8:48 PM CST | Tornado Watch | SPC | 9 hr |
The nearest sounding before it
Shreveport, LA (KSHV), launched 00:00Z, 5.3 hours before the alert went out and 202 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.
- 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
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, 10:11 PM CST, 1 hour 8 minutes earlier.
Area forecast discussion, Dec 23, 10:11 PM CST, 1 hour 8 minutes before
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</html>Hazardous weather outlook, Dec 23, 3:17 PM CST, 8 hours 2 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.
The office that day
Everything else NWS Houston/Galveston, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 23, 6:01 PM CST | Severe Thunderstorm Warning | HGX | Houston | 44 min |
| 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 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, 2009Every 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.