Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 61, NWS Houston/Galveston, TX

April 17, 2009Liberty County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Apr 17, 2009, 11:51 PM CDT for Liberty County, Texas. It was in force for 39 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 17, 2009, 11:51 PM CDT (04:51 UTC)
Expired
Apr 18, 2009, 12:30 AM CDT
In force
39 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon

County Liberty County, TX

The radar

The Houston radar (KHGX), 80 km from the middle of the area, began a volume at 04:51 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 nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 4.9 hours before the alert went out and 365 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, Corpus Christi, TX at 00:00Z on 2009-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3044 joules per kilogram.LCLLFCEL10008507005003002001001 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, Corpus Christi, TX at 00:00Z on 2009-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 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
3044 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
729 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
-85 m²/s²
Significant tornado parameter
-0.6
Supercell composite
-2.3

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 17, 10:20 PM CDT, 1 hour 31 minutes earlier.

Area forecast discussion, Apr 17, 10:20 PM CDT, 1 hour 31 minutes before
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Hazardous weather outlook, Apr 17, 2:12 PM CDT, 9 hours 39 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
212 PM CDT FRI APR 17 2009

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-181200-
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-
212 PM CDT FRI APR 17 2009

...SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS THROUGH
SATURDAY EVENING...

...FLOOD WATCH IN EFFECT FOR ALL OF SOUTHEAST TEXAS THROUGH
SATURDAY EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

DISTURBANCES ROTATING AROUND A STRONG STORM SYSTEM WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS
OF SOUTHEAST TEXAS. SOME OF THE STRONGER STORMS MAY BECOME SEVERE
AND COULD PRODUCE STRONG DAMAGING WINDS...LARGE HAIL AND ISOLATED
TORNADOES. IN ADDITION TO THE SEVERE WEATHER THREAT...VERY HIGH MOISTURE
LEVELS WILL PERSIST ACROSS MUCH OF THE AREA AND WILL SUPPORT THE THREAT
FOR LOCALLY HEAVY RAINFALL. FLOODING OF STREETS...FEEDER ROADS...SECONDARY
ROADS...LOW WATER CROSSINGS...AND AREA CREEKS AND RIVERS WILL BE POSSIBLE
WHERE TRAINING OF STORMS OCCURS.

.DAY TWO...SATURDAY THROUGH SATURDAY NIGHT

DISTURBANCES ROTATING AROUND A STRONG STORM SYSTEM WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS PORTIONS
OF SOUTHEAST TEXAS. SOME OF THE STRONGER STORMS MAY BECOME SEVERE
AND COULD PRODUCE STRONG DAMAGING WINDS...LARGE HAIL AND ISOLATED
TORNADOES. IN ADDITION TO THE SEVERE WEATHER THREAT...VERY HIGH MOISTURE
LEVELS WILL PERSIST ACROSS MUCH OF THE AREA AND WILL SUPPORT THE THREAT
FOR LOCALLY HEAVY RAINFALL. FLOODING OF STREETS...FEEDER ROADS...SECONDARY
ROADS...LOW WATER CROSSINGS...AND AREA CREEKS AND RIVERS WILL BE POSSIBLE
WHERE TRAINING OF STORMS OCCURS.

RAINFALL TOTALS FOR TODAY AND SATURDAY ARE EXPECTED TO AVERAGE 2 TO
4 INCHES. WHERE HEAVY RAINFALL HAS ALREADY OCCURRED...ISOLATED TWO
DAY TOTALS OF 15 TO 20 INCHES ARE POSSIBLE...ESPECIALLY ACROSS PORTIONS
OF NORTHWEST COLORADO COUNTY AND NORTHERN AUSTIN COUNTY. THE THREAT
FOR THE HEAVIEST RAINFALL IS EXPECTED GENERALLY ALONG AND NORTH OF THE
U.S. HIGHWAY 59 CORRIDOR...GENERALLY ALONG AND NORTH OF A LINE FROM
EDNA TO RICHMOND TO HOUSTON TO CLEVELAND TO CORRIGAN.

A COLD FRONT WILL CROSS THE AREA LATE SATURDAY NIGHT ENDING THE RAIN
CHANCES AND SEVERE WEATHER THREAT ACTIVITY SHIFTS TO THE EAST OF THE
AREA.

.DAYS THREE THROUGH SEVEN...SUNDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Local storm report, Apr 17, 7:31 PM CDT, 4 hours 20 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Apr 17, 9:25 PM CDTRiver Flood WarningHGXJackson, Lavaca3 days
Apr 17, 9:25 PM CDTRiver Flood WarningHGXJackson, Lavaca4 days
Apr 17, 9:25 PM CDTRiver Flood WarningHGXJackson5 days
Apr 18, 2:37 AM CDTSevere Thunderstorm WarningHGXPolk38 min
Apr 18, 6:41 AM CDTMarine Weather StatementHGX2 hr
Apr 18, 7:39 AM CDTAreal Flood AdvisoryHGXBurleson, Washington3 hr
Apr 18, 9:35 AM CDTSmall Craft AdvisoryHGX9 hr
Apr 18, 9:37 AM CDTTornado WarningHGXGrimes, Madison, Walker23 min
Apr 18, 9:47 AM CDTTornado WarningHGXAustin, Colorado, Washington43 min
Apr 18, 9:54 AM CDTRiver Flood WarningHGXJackson4 days
Apr 18, 10:32 AM CDTTornado WarningHGXWashington28 min
Apr 18, 10:49 AM CDTTornado WarningHGXGrimes, Walker26 min
Apr 18, 10:52 AM CDTAreal Flood AdvisoryHGXAustin, Colorado, Washington3 hr
Apr 18, 11:12 AM CDTAreal Flood AdvisoryHGXGrimes, Harris, Montgomery, Waller3 hr
Apr 18, 11:33 AM CDTAreal Flood AdvisoryHGXGrimes, Harris, Montgomery, Waller2 hr
Apr 18, 11:40 AM CDTSevere Thunderstorm WarningHGXWharton50 min
Apr 18, 11:44 AM CDTAreal Flood AdvisoryHGXFort Bend, Wharton2 hr
Apr 18, 12:02 PM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend, Wharton43 min
Apr 18, 12:08 PM CDTTornado WarningHGXBrazoria, Fort Bend, Wharton37 min
Apr 18, 12:15 PM CDTSevere Thunderstorm WarningHGXLiberty, Montgomery, San Jacinto45 min
Apr 18, 12:26 PM CDTSpecial Marine WarningHGX64 min
Apr 18, 12:43 PM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend47 min
Apr 18, 12:46 PM CDTFlash Flood WarningHGXHarris, Montgomery119 min
Apr 18, 1:22 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend, Galveston3 hr
Apr 18, 1:29 PM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend, Galveston, Harris46 min
Apr 18, 1:30 PM CDTSevere Thunderstorm WarningHGXFort Bend, Wharton45 min
Apr 18, 1:42 PM CDTFlash Flood WarningHGXChambers, Harris3 hr
Apr 18, 2:02 PM CDTFlash Flood WarningHGXAustin, Colorado, Fort Bend, Wharton3 hr
Apr 18, 2:06 PM CDTSevere Thunderstorm WarningHGXBrazoria, Galveston, Harris24 min
Apr 18, 2:13 PM CDTSpecial Marine WarningHGX92 min
Apr 18, 3:04 PM CDTRiver Flood WarningHGXAustin, Fort Bend, Wharton55 hr
Apr 18, 3:05 PM CDTSpecial Marine WarningHGX55 min
Apr 18, 3:05 PM CDTSevere Thunderstorm WarningHGXChambers, Galveston, Harris40 min
Apr 18, 3:20 PM CDTCoastal Flood StatementHGXChambers, Galveston3 hr
Apr 18, 3:33 PM CDTSevere Thunderstorm WarningHGXChambers42 min
Apr 18, 3:46 PM CDTTornado WarningHGXBrazoria, Galveston29 min
Apr 18, 4:04 PM CDTTornado WarningHGXGalveston19 min
Apr 18, 4:07 PM CDTRiver Flood WarningHGXGalveston, Harris38 hr
Apr 18, 4:07 PM CDTSpecial Marine WarningHGX53 min
Apr 18, 4:12 PM CDTSevere Thunderstorm WarningHGXGalveston33 min
Apr 18, 4:15 PM CDTFlash Flood WarningHGXBrazoria, Chambers, Galveston, Harris3 hr
Apr 18, 4:19 PM CDTSevere Thunderstorm WarningHGXChambers41 min
Apr 18, 4:23 PM CDTAreal Flood AdvisoryHGXHarris3 hr
Apr 18, 4:24 PM CDTRiver Flood WarningHGXHarris18 hr
Apr 18, 4:24 PM CDTSpecial Marine WarningHGX96 min
Apr 18, 4:46 PM CDTAreal Flood AdvisoryHGXBrazoria3 hr
Apr 18, 4:59 PM CDTAreal Flood AdvisoryHGXBrazoria, Matagorda, Wharton2 hr
Apr 18, 4:59 PM CDTRiver Flood WarningHGXHarris17 hr
Apr 18, 5:21 PM CDTRiver Flood WarningHGXMontgomery52 hr
Apr 18, 5:21 PM CDTRiver Flood WarningHGXHarris, Liberty17 hr
Apr 18, 5:21 PM CDTRiver Flood WarningHGXMontgomery17 hr
Apr 18, 5:21 PM CDTRiver Flood WarningHGXHarris, Montgomery4 hr
Apr 18, 5:21 PM CDTRiver Flood WarningHGXHarris, Montgomery17 hr
Apr 18, 5:37 PM CDTRiver Flood WarningHGXGalveston, Harris27 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.