Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 50, NWS Houston/Galveston, TX

April 16, 2009Houston County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Apr 16, 2009, 8:30 PM CDT for Houston County, Texas. It was in force for 45 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 16, 2009, 8:30 PM CDT (01:30 UTC)
Expired
Apr 16, 2009, 9:15 PM CDT
In force
45 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 01:32 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

Shreveport, LA (KSHV), launched 00:00Z, 1.5 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-pSkew-T log-p diagram, Shreveport, LA at 00:00Z on 2009-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Shreveport, LA at 00:00Z on 2009-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2029 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
34 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 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 Apr 16, 8:26 PM CDT, 4 minutes earlier.

Area forecast discussion, Apr 16, 8:26 PM CDT, 4 minutes before
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Hazardous weather outlook, Apr 16, 3:13 PM CDT, 5 hours 17 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
313 PM CDT THU APR 16 2009

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-172015-
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-
313 PM CDT THU APR 16 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

AN APPROACHING UPPER LEVEL DISTURBANCE AND INCREASING MOISTURE
LEVELS WILL RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS THIS AFTERNOON AND TONIGHT.

.DAYS TWO THROUGH THREE...FRIDAY THROUGH SATURDAY NIGHT

A SLOW MOVING UPPER LEVEL STORM SYSTEM WILL DRIFT ACROSS THE FOUR
CORNERS REGION FROM THURSDAY NIGHT TO CENTRAL OKLAHOMA ON
SATURDAY NIGHT. PERSISTENT MOIST SOUTHEASTERLY FLOW COMBINED WITH
A SERIES OF UPPER LEVEL DISTURBANCES ROTATING AROUND THE UPPER
LOW WILL RESULT IN SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS
THIS PERIOD. THE COMBINATION OF STRONG INSTABILITY AND PRONOUNCED
LOW LEVEL SHEAR WILL RESULT IN THE POTENTIAL FOR SEVERE
THUNDERSTORMS BOTH FRIDAY AND SATURDAY. THE MOST LIKELY AREAS FOR
SEVERE THUNDERSTORMS APPEAR TO BE MAINLY NORTH OF INTERSTATE 10
AND WEST OF INTERSTATE 45. THIS AREA COULD EASILY EXPAND FRIDAY
NIGHT TO ALL AREAS NORTH OF INTERSTATE 10. THE MAIN SEVERE
THREATS WILL BE STRAIGHT LINE WINDS AND HAIL...BUT SHOULD STORMS
BEGIN TO ROTATE...AN ISOLATED TORNADO MAY BE POSSIBLE.

IN ADDITION...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE FRIDAY AND
SATURDAY. RAINFALL AMOUNTS FOR THE ENTIRE EVENT ARE EXPECTED TO
AVERAGE 1 TO 3 INCHES...WITH ISOLATED TOTALS OF 4 TO 7 INCHES
POSSIBLE.

STRONG EASTERLY WINDS WILL RESULT IN ELEVATED TIDE LEVELS ALONG
THE UPPER TEXAS COAST AND THE SHORES OF THE BAYS ON FRIDAY.

A COLD FRONT WILL CROSS THE AREA LATE SATURDAY NIGHT ENDING THE
RAIN CHANCES AS THE THUNDERSTORM ACTIVITY SHIFTS INTO THE GULF OF
MEXICO.

.DAYS FOUR THROUGH SEVEN...SUNDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED FRIDAY AND SATURDAY.

In the hours before

Special weather statement, Apr 16, 6:53 PM CDT, 1 hour 37 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
653 PM CDT THU APR 16 2009

TXZ176-170100-
MADISON-
INCLUDING THE CITY OF...MADISONVILLE
653 PM CDT THU APR 16 2009

PEA SIZE HAIL IS POSSIBLE ACROSS NORTHERN PORTIONS OF THE
COUNTY...GENERALLY ALONG THE MADISON AND LEON COUNTY LINE IN THE
VICINITY OF INTERSTATE 45...AS A SMALL STORM MOVES EAST NORTHEAST
ACROSS THE REGION. WE WILL CONTINUE TO MONITOR THE STORM AND ISSUE
A SEVERE THUNDERSTORM WARNING IF IT BECOMES NECESSARY.

TXZ178-170100-
SAN JACINTO-
INCLUDING THE CITIES OF...SHEPHERD...COLDSPRING
653 PM CDT THU APR 16 2009

PEA SIZE HAIL IS POSSIBLE ACROSS CENTRAL PORTIONS OF THE
COUNTY...GENERALLY ALONG HIGHWAY 105 FROM EVERGREEN TO COLDSPRING...AS
A STORM MOVES EAST NORTHEAST ACROSS THE REGION. WE WILL CONTINUE
TO MONITOR THE STORM AND ISSUE A SEVERE THUNDERSTORM WARNING IF IT
BECOMES NECESSARY.
Special weather statement, Apr 16, 7:19 PM CDT, 1 hour 11 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
719 PM CDT THU APR 16 2009

TXZ163-170130-
HOUSTON-
INCLUDING THE CITY OF...CROCKETT
719 PM CDT THU APR 16 2009

...STRONG STORM MOVING THROUGH WESTERN HOUSTON COUNTY...

PEA TO 1/2 INCH HAIL IS POSSIBLE ACROSS THE WESTERN 1/3 OF HOUSTON
COUNTY...ESPECIALLY CLOSER TO THE HOUSTON AND LEON COUNTY
LINE...AS A STRONG STORM MOVES NORTHEAST ACROSS THE REGION. WIND
GUSTS TO 40 MPH ARE ALSO POSSIBLE. THIS STORM WILL MOVE OVER
HOUSTON COUNTY LAKE AROUND 730 PM. WE WILL CONTINUE TO MONITOR THE
STORM AND ISSUE A SEVERE THUNDERSTORM WARNING IF IT BECOMES
NECESSARY.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 16, 7:54 PM CDTSevere Thunderstorm WarningHGXHouston36 min
Apr 17, 10:25 AM CDTSevere Thunderstorm WarningHGXAustin, Colorado50 min
Apr 17, 10:36 AM CDTAreal Flood AdvisoryHGXAustin, Burleson, Colorado, Washington114 min
Apr 17, 11:06 AM CDTFlash Flood WarningHGXColorado114 min
Apr 17, 11:12 AM CDTSevere Thunderstorm WarningHGXAustin, Colorado48 min
Apr 17, 11:24 AM CDTFlood WatchHGXAustin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more33 hr
Apr 17, 12:13 PM CDTSevere Thunderstorm WarningHGXAustin, Colorado, Waller, Washington47 min
Apr 17, 12:21 PM CDTTornado WarningHGXAustin, Colorado, Waller39 min
Apr 17, 12:30 PM CDTTornado WarningHGXAustin, Waller, Washington36 min
Apr 17, 12:45 PM CDTFlash Flood WarningHGXAustin, Colorado, Washington3 hr
Apr 17, 12:53 PM CDTAreal Flood AdvisoryHGXBrazos, Burleson3 hr
Apr 17, 1:38 PM CDTSevere Thunderstorm WarningHGXAustin, Harris, Waller, Washington37 min
Apr 17, 1:58 PM CDTTornado WarningHGXAustin, Harris, Waller, Washington21 min
Apr 17, 2:24 PM CDTAreal Flood AdvisoryHGXAustin, Brazos, Grimes, Harris, Montgomery, Walker and 2 more3 hr
Apr 17, 2:38 PM CDTFlash Flood WarningHGXBrazos, Burleson3 hr
Apr 17, 3:04 PM CDTSevere Thunderstorm WarningHGXColorado56 min
Apr 17, 3:14 PM CDTRiver Flood WarningHGXLavaca65 hr
Apr 17, 3:15 PM CDTAreal Flood AdvisoryHGXAustin, Colorado, Harris, Liberty, Montgomery, Waller3 hr
Apr 17, 3:27 PM CDTSevere Thunderstorm WarningHGXHarris, Montgomery48 min
Apr 17, 3:33 PM CDTRiver Flood WarningHGXLavaca43 hr
Apr 17, 3:38 PM CDTFlash Flood WarningHGXAustin, Colorado, Fort Bend, Waller, Washington112 min
Apr 17, 3:43 PM CDTSevere Thunderstorm WarningHGXHarris, Montgomery47 min
Apr 17, 3:51 PM CDTFlash Flood WarningHGXHarris, Montgomery3 hr
Apr 17, 3:58 PM CDTSevere Thunderstorm WarningHGXAustin, Colorado47 min
Apr 17, 4:01 PM CDTSevere Thunderstorm WarningHGXHarris, Liberty, Montgomery59 min
Apr 17, 4:05 PM CDTSpecial Marine WarningHGX115 min
Apr 17, 4:16 PM CDTRiver Flood WarningHGXColorado, Wharton18 hr
Apr 17, 4:20 PM CDTSevere Thunderstorm WarningHGXAustin, Fort Bend, Grimes, Harris, Montgomery, Waller40 min
Apr 17, 4:28 PM CDTFlash Flood WarningHGXHarris, Liberty, Montgomery3 hr
Apr 17, 5:49 PM CDTSpecial Marine WarningHGX73 min
Apr 17, 5:51 PM CDTAreal Flood AdvisoryHGXGalveston54 min
Apr 17, 6:22 PM CDTSpecial Marine WarningHGX83 min
Apr 17, 6:45 PM CDTSpecial Marine WarningHGX90 min

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.