Alert archive / Texas / Tornado Warnings in 2009

Tornado Warning 14, NWS Houston/Galveston, TX

April 18, 2009Austin County, Colorado County, Washington County, Texas

NWS Houston/Galveston, TX issued this tornado warning at Apr 18, 2009, 9:47 AM CDT for Austin County, Colorado County, Washington County, Texas. It was in force for 43 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 18, 2009, 9:47 AM CDT (14:47 UTC)
Expired: Apr 18, 2009, 10:30 AM CDT
In force: 43 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon

Counties Austin County, TX, Colorado County, TX, Washington County, TX

The radar

The Ft Hood radar (KGRK), 131 km from the middle of the area, began a volume at 14:51 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 18, 4:21 AM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 2.8 hours before the alert went out and 259 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: 1763 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 486 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 8.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Apr 18, 7:21 AM CDT, 2 hours 26 minutes earlier.

Area forecast discussion, Apr 18, 7:21 AM CDT, 2 hours 26 minutes before

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Hazardous weather outlook, Apr 18, 3:44 AM CDT, 6 hours 3 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
344 AM CDT SAT APR 18 2009

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-191200-
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-
344 AM CDT SAT APR 18 2009

...LOCALLY HEAVY RAINFALL AND FLOODING POSSIBLE ACROSS SOUTHEAST
TEXAS THROUGH THIS EVENING...

...SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH THIS EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

DISTURBANCES ROTATING AROUND A STRONG STORM SYSTEM WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST
TEXAS. AT LEAST ONE MORE ROUND OF SIGNIFICANT THUNDERSTORMS IS
EXPECTED ACROSS THE AREA TODAY THROUGH THIS EVENING.

VERY HIGH MOISTURE LEVELS WILL PERSIST. AN ADDITIONAL 1 TO 3
INCHES OF RAIN IS EXPECTED ACROSS SOUTHEAST TEXAS THROUGH
TONIGHT...WITH AN ADDITIONAL 4 TO 8 INCHES POSSIBLE IN ISOLATED
SPOTS. THIS RAIN...FALLING ON TOP OF ALREADY SATURATED GROUNDS...
WILL RESULT IN THE POTENTIAL FOR FLOODING. THE GREATEST THREAT OF
FLOODING WILL BE FOR AREAS NORTH OF A COLUMBUS TO CONROE TO
LIVINGSTON LINE WHERE THE HEAVIEST RAIN HAS FALLEN SO FAR. A FLOOD
WATCH IS IN EFFECT FOR ALL OF SOUTHEAST TEXAS THROUGH THIS EVENING.

A FEW STORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE. THE PRIMARY
SEVERE WEATHER THREAT WILL BE HAIL...WITH AN ADDITIONAL THREAT OF
ISOLATED DOWNBURSTS OR TORNADOES.

A FRONT WILL CROSS THE AREA DURING THE LATE EVENING HOURS ENDING
THE THUNDERSTORMS FROM WEST TO EAST.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED AT ANY TIME THROUGH THIS EVENING.

In the hours before

Local storm report, Apr 18, 9:31 AM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
931 AM CDT SAT APR 18 2009

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

1047 AM     HAIL             WEIMAR                  29.70N 96.78W
04/17/2009  M0.75 INCH       COLORADO           TX   EMERGENCY MNGR

            PENNY SIZED HAIL REPORTED IN WEIMAR.

1225 PM     TSTM WND DMG     BRENHAM                 30.16N 96.40W
04/17/2009                   WASHINGTON         TX   LAW ENFORCEMENT

            HARTZ CHICKEN RESTAURANT ROOF BLOWN OFF...RESIDENTIAL
            HOME WINDOWS BLOWN OUT. TREES AND POWER LINES DOWN AROUND
            COUNTY.

1248 PM     HEAVY RAIN       WEIMAR                  29.70N 96.78W
04/17/2009  M5.00 INCH       COLORADO           TX   COUNTY OFFICIAL

            TWO ROADS CLOSED INCLUDING FM 155...JUST SOUTH OF WEIMAR.

0135 PM     HEAVY RAIN       COLLEGE STATION         30.60N 96.31W
04/17/2009  M3.50 INCH       BRAZOS             TX   TRAINED SPOTTER

            3.5 INCHES OF RAIN IN SOUTHWOOD VALLEY NEIGHBORHOOD.

0200 PM     HEAVY RAIN       COLUMBUS                29.70N 96.55W
04/17/2009  M4.00 INCH       COLORADO           TX   LAW ENFORCEMENT

0200 PM     HEAVY RAIN       FRELSBURG               29.87N 96.55W
04/17/2009  M10.00 INCH      COLORADO           TX   LAW ENFORCEMENT

            10 INCHES OF RAIN IN NORTHERN COLORADO COUNTY.

0200 PM     HEAVY RAIN       WEIMAR                  29.70N 96.78W
04/17/2009  M8.00 INCH       COLORADO           TX   LAW ENFORCEMENT

0420 PM     HAIL             10 NW HOUSTON           29.87N 95.50W
04/17/2009  E1.00 INCH       HARRIS             TX   COUNTY OFFICIAL

            HARRIS COUNTY FLOOD CONTROL REPORTED PENNY TO QUARTER
            SIZE HAIL NEAR THE INTERSECTION OF INTERSTATE 610 AND HWY
            290.

0630 PM     HEAVY RAIN       MONAVILLE               29.95N 96.04W
04/17/2009  M3.50 INCH       WALLER             TX   TRAINED SPOTTER

            3.5 INCHES OF RAIN IN MONAVILLE.

1153 PM     HAIL             DAYTON                  30.05N 94.90W
04/17/2009  E0.75 INCH       LIBERTY            TX   LAW ENFORCEMENT

1200 AM     HAIL             LIBERTY                 30.05N 94.80W
04/18/2009  E0.75 INCH       LIBERTY            TX   LAW ENFORCEMENT

1202 AM     HAIL             6 NNW FRIENDSWOOD       29.59N 95.22W
04/18/2009  E0.88 INCH       HARRIS             TX   TRAINED SPOTTER

            NICKEL SIZE HAIL JUST SOUTH OF BELTWAY 8 BETWEEN
            BLACKHAWK AND BEAMER.

1204 AM     HAIL             HOUSTON                 29.77N 95.39W
04/18/2009  E0.50 INCH       HARRIS             TX   PUBLIC

            DIME SIZED HAIL REPORTED AT INTERSECTION OF FUQUA AND
            BEAMER IN SOUTHEAST HOUSTON.

&&

42

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 17, 9:25 PM CDT	River Flood Warning	HGX	Jackson, Lavaca	3 days
Apr 17, 9:25 PM CDT	River Flood Warning	HGX	Jackson, Lavaca	4 days
Apr 17, 9:25 PM CDT	River Flood Warning	HGX	Jackson	5 days
Apr 17, 11:51 PM CDT	Severe Thunderstorm Warning	HGX	Liberty	39 min
Apr 18, 2:37 AM CDT	Severe Thunderstorm Warning	HGX	Polk	38 min
Apr 18, 6:41 AM CDT	Marine Weather Statement	HGX		2 hr
Apr 18, 7:39 AM CDT	Areal Flood Advisory	HGX	Burleson, Washington	3 hr
Apr 18, 9:35 AM CDT	Small Craft Advisory	HGX		9 hr
Apr 18, 9:37 AM CDT	Tornado Warning	HGX	Grimes, Madison, Walker	23 min
Apr 18, 9:54 AM CDT	River Flood Warning	HGX	Jackson	4 days
Apr 18, 10:32 AM CDT	Tornado Warning	HGX	Washington	28 min
Apr 18, 10:49 AM CDT	Tornado Warning	HGX	Grimes, Walker	26 min
Apr 18, 10:52 AM CDT	Areal Flood Advisory	HGX	Austin, Colorado, Washington	3 hr
Apr 18, 11:12 AM CDT	Areal Flood Advisory	HGX	Grimes, Harris, Montgomery, Waller	3 hr
Apr 18, 11:33 AM CDT	Areal Flood Advisory	HGX	Grimes, Harris, Montgomery, Waller	2 hr
Apr 18, 11:40 AM CDT	Severe Thunderstorm Warning	HGX	Wharton	50 min
Apr 18, 11:44 AM CDT	Areal Flood Advisory	HGX	Fort Bend, Wharton	2 hr
Apr 18, 12:02 PM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend, Wharton	43 min
Apr 18, 12:08 PM CDT	Tornado Warning	HGX	Brazoria, Fort Bend, Wharton	37 min
Apr 18, 12:15 PM CDT	Severe Thunderstorm Warning	HGX	Liberty, Montgomery, San Jacinto	45 min
Apr 18, 12:26 PM CDT	Special Marine Warning	HGX		64 min
Apr 18, 12:43 PM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend	47 min
Apr 18, 12:46 PM CDT	Flash Flood Warning	HGX	Harris, Montgomery	119 min
Apr 18, 1:22 PM CDT	Flash Flood Warning	HGX	Brazoria, Fort Bend, Galveston	3 hr
Apr 18, 1:29 PM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend, Galveston, Harris	46 min
Apr 18, 1:30 PM CDT	Severe Thunderstorm Warning	HGX	Fort Bend, Wharton	45 min
Apr 18, 1:42 PM CDT	Flash Flood Warning	HGX	Chambers, Harris	3 hr
Apr 18, 2:02 PM CDT	Flash Flood Warning	HGX	Austin, Colorado, Fort Bend, Wharton	3 hr
Apr 18, 2:06 PM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Galveston, Harris	24 min
Apr 18, 2:13 PM CDT	Special Marine Warning	HGX		92 min
Apr 18, 3:04 PM CDT	River Flood Warning	HGX	Austin, Fort Bend, Wharton	55 hr
Apr 18, 3:05 PM CDT	Special Marine Warning	HGX		55 min
Apr 18, 3:05 PM CDT	Severe Thunderstorm Warning	HGX	Chambers, Galveston, Harris	40 min
Apr 18, 3:20 PM CDT	Coastal Flood Statement	HGX	Chambers, Galveston	3 hr
Apr 18, 3:33 PM CDT	Severe Thunderstorm Warning	HGX	Chambers	42 min
Apr 18, 3:46 PM CDT	Tornado Warning	HGX	Brazoria, Galveston	29 min
Apr 18, 4:04 PM CDT	Tornado Warning	HGX	Galveston	19 min
Apr 18, 4:07 PM CDT	River Flood Warning	HGX	Galveston, Harris	38 hr
Apr 18, 4:07 PM CDT	Special Marine Warning	HGX		53 min
Apr 18, 4:12 PM CDT	Severe Thunderstorm Warning	HGX	Galveston	33 min
Apr 18, 4:15 PM CDT	Flash Flood Warning	HGX	Brazoria, Chambers, Galveston, Harris	3 hr
Apr 18, 4:19 PM CDT	Severe Thunderstorm Warning	HGX	Chambers	41 min
Apr 18, 4:23 PM CDT	Areal Flood Advisory	HGX	Harris	3 hr
Apr 18, 4:24 PM CDT	River Flood Warning	HGX	Harris	18 hr
Apr 18, 4:24 PM CDT	Special Marine Warning	HGX		96 min
Apr 18, 4:46 PM CDT	Areal Flood Advisory	HGX	Brazoria	3 hr
Apr 18, 4:59 PM CDT	Areal Flood Advisory	HGX	Brazoria, Matagorda, Wharton	2 hr
Apr 18, 4:59 PM CDT	River Flood Warning	HGX	Harris	17 hr
Apr 18, 5:21 PM CDT	River Flood Warning	HGX	Montgomery	52 hr
Apr 18, 5:21 PM CDT	River Flood Warning	HGX	Harris, Liberty	17 hr
Apr 18, 5:21 PM CDT	River Flood Warning	HGX	Montgomery	17 hr
Apr 18, 5:21 PM CDT	River Flood Warning	HGX	Harris, Montgomery	4 hr
Apr 18, 5:21 PM CDT	River Flood Warning	HGX	Harris, Montgomery	17 hr
Apr 18, 5:37 PM CDT	River Flood Warning	HGX	Galveston, Harris	27 hr

Nearby

Tornado Warnings in Texas, 2009 Every tornado warning in 2009 Tornadoes 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.