Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 19, NWS Houston/Galveston, TX

March 25, 2009Polk County, Trinity County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Mar 25, 2009, 7:22 PM CDT for Polk County, Trinity County, Texas. It was in force for 38 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
Mar 25, 2009, 7:22 PM CDT (00:22 UTC)
Expired
Mar 25, 2009, 8:00 PM CDT
In force
38 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon

Counties Polk County, TX, Trinity County, TX

The radar

The Houston radar (KHGX), 164 km from the middle of the area, began a volume at 00:23 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.

IssuedProductOfficeLasted
Mar 25, 2:06 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.4 hours before the alert went out and 194 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, Lake Charles Mun, LA at 00:00Z on 2009-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3131 joules per kilogram.LCLEL10008507005003002001001 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, Lake Charles Mun, LA at 00:00Z on 2009-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.1939587897Sfc1 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
3131 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
474 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
2.5
Supercell composite
9.3

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 Mar 25, 7:10 PM CDT, 12 minutes earlier.

Area forecast discussion, Mar 25, 7:10 PM CDT, 12 minutes before
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Hazardous weather outlook, Mar 25, 3:41 PM CDT, 3 hours 41 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
341 PM CDT WED MAR 25 2009

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-261200-
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-
341 PM CDT WED MAR 25 2009

...SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS ALL OF SOUTHEAST
TEXAS THIS EVENING AND AGAIN THURSDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...REST OF THIS AFTERNOON AND TONIGHT

A STALLED FRONT DRAPED WEST TO EAST ACROSS THE CENTRAL PORTIONS OF
THE AREA WILL STALL AGAIN THIS EVENING ACROSS THE NORTHERN
COUNTIES OF SOUTHEAST TEXAS. SCATTERED THUNDERSTORMS DEVELOPING
OVER THE EDWARDS PLATEAU AND HILL COUNTRY ARE EXPECTED TO SPREAD
EAST INTO THE AREA AFTER 6 PM AS AN UPPER LEVEL DISTURBANCE
APPROACHES FROM THE WEST.

THE BULK OF THE THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP
NORTH OF THE FRONT. THE POTENTIAL EXISTS FOR A FEW OF THESE
STORMS TO BECOME SEVERE...WITH THE GREATEST SEVERE WEATHER
POTENTIAL NORTH OF INTERSTATE 10. ANY STORMS THAT BECOME SEVERE
WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL...DAMAGING
WINDS...AND ISOLATED TORNADOES. IN ADDITION...LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE. RAINFALL AMOUNTS WILL AVERAGE 1/2 TO 1
INCH WITH ISOLATED HIGHER TOTALS.

SOUTH OF THE FRONT...LESS THUNDERSTORM COVERAGE IS
EXPECTED DUE TO A CAPPING LAYER OF WARM AIR IN THE ATMOSPHERE.
HOWEVER...ANY STORMS THAT MANAGE TO BREAK THE CAP SOUTH OF THE
FRONT WILL ALSO HAVE THE POTENTIAL TO BECOME SEVERE.

THE SEVERE WEATHER THREAT IS EXPECTED TO END BY MIDNIGHT AS THE
UPPER LEVEL DISTURBANCE MOVES EAST OF THE AREA.

.DAY TWO...THURSDAY AND THURSDAY NIGHT

ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO CROSS SOUTHEAST
TEXAS THURSDAY AFTERNOON. THIS DISTURBANCE WILL COMBINE WITH THE
MOIST AND UNSTABLE AIRMASS IN PLACE TO GENERATE SCATTERED SHOWERS
AND THUNDERSTORMS. THE AIRMASS IS EXPECTED TO BECOME STRONGLY
UNSTABLE OVER THE AREA THURSDAY AFTERNOON...WITH CAPPING LESS OF
AN ISSUE THAN TODAY. THE COMBINATION OF THE STRONG INSTABILITY AND
LOW LEVEL SHEAR WILL FAVOR THE POTENTIAL FOR ISOLATED SUPERCELLS
PRODUCING LARGE HAIL...DAMAGING WINDS...OR ISOLATED TORNADOES.

.DAY THREE...FRIDAY THROUGH FRIDAY NIGHT

A COLD FRONT WILL TREK ACROSS SOUTHEASTERN TEXAS THROUGH THE
DAYTIME HOURS...REACHING THE COAST AROUND SUNSET. SCATTERED
THUNDERSTORMS MAY DEVELOP AHEAD OF THE MAIN SURFACE FRONT...OR
OVER THE EASTERN HALF OF SOUTHEAST TEXAS. THERE IS A SMALL WINDOW
OF POSSIBILITY FOR A FEW SEVERE STORMS OVER THE EASTERN HALF OF
SOUTHEAST TEXAS FROM MIDDAY THROUGH MID AFTERNOON FRIDAY.

.DAYS FOUR THROUGH SEVEN...SATURDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE TODAY...THURSDAY...AND FRIDAY.

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 25, 7:15 PM CDTSevere Thunderstorm WarningHGXBrazos, Grimes, Washington30 min
Mar 25, 7:40 PM CDTTornado WarningHGXGrimes, Montgomery, San Jacinto, Walker50 min
Mar 25, 8:10 PM CDTTornado WarningHGXHarris, Montgomery50 min
Mar 25, 8:25 PM CDTTornado WarningHGXHarris, Liberty, Montgomery, San Jacinto50 min
Mar 25, 9:05 PM CDTSevere Thunderstorm WarningHGXChambers, Liberty40 min
Mar 25, 10:01 PM CDTSpecial Marine WarningHGX59 min
Mar 26, 1:36 PM CDTSevere Thunderstorm WarningHGXJackson, Wharton39 min
Mar 26, 1:54 PM CDTSevere Thunderstorm WarningHGXFort Bend51 min
Mar 26, 2:34 PM CDTAreal Flood AdvisoryHGXFort Bend, Harris116 min
Mar 26, 3:11 PM CDTSevere Thunderstorm WarningHGXHarris49 min
Mar 26, 3:38 PM CDTAreal Flood AdvisoryHGXFort Bend, Harris, Montgomery112 min
Mar 26, 4:19 PM CDTSpecial Marine WarningHGX86 min
Mar 26, 4:30 PM CDTSpecial Marine WarningHGX60 min
Mar 26, 5:08 PM CDTSpecial Marine WarningHGX52 min
Mar 26, 5:44 PM CDTSpecial Marine WarningHGX91 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.