Alert archive / Texas / Tornado Watches in 2009

Tornado Watch 65

March 25, 200915 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 25, 2009, 7:12 PM CDT for 15 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Mar 25, 2009, 7:12 PM CDT (00:12 UTC)
Expired
Mar 26, 2009, 1:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Austin County, TX, Brazoria County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jackson County, TX, Jefferson County, TX, Liberty County, TX, Matagorda County, TX, Orange County, TX, Waller County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 45 km from the middle of the area, began a volume at 00:13 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 25, 8:10 PM CDTTornado WarningHGXHarris, Montgomery50 min
Mar 25, 8:22 PM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Tyler38 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, 9:27 PM CDTSevere Thunderstorm WarningLCHHardin, Jasper, Jefferson, Newton, Orange48 min
Mar 25, 10:14 PM CDTSevere Thunderstorm WarningLCHHardin, Jefferson, Orange31 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.2 hours before the alert went out and 230 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

The text

As transmitted, in the capitals the NWS used until 2016.

612 
WWUS20 KWNS 260012
SEL5  
SPC WW 260012
TXZ000-CWZ000-260600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 65
NWS STORM PREDICTION CENTER NORMAN OK
710 PM CDT WED MAR 25 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       SOUTHEAST TEXAS
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 710 PM
UNTIL 100 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES NORTHWEST OF
PALACIOS TEXAS TO 15 MILES EAST NORTHEAST OF PORT ARTHUR TEXAS. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 63...WW 64...

DISCUSSION...BROKEN LINE OF STRONG TO SEVERE THUNDERSTORMS WILL
CONTINUE DEVELOPING ALONG AND AHEAD OF SURFACE COLD FRONT EXPECTED
TO PUSH SEWD INTO SOUTHEASTERN TX THIS EVENING.  DEEP LAYER SHEAR
REMAINS QUITE STRONG...AND LOW LEVEL SHEAR WILL BE SUFFICIENT FOR
ISOLATED TORNADOES.  LARGE HAIL AND DAMAGING WINDS WILL BE
ADDITIONAL HAZARDS FROM THE STRONGER CORES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 29035.


...EVANS

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 25, 7:31 PM CDTMesoscale DiscussionSPCAustin, Brazos, Burleson, Fayette, Grimes, Harris and 9 more59 min
Mar 26, 9:14 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Blanco, Caldwell, Comal and 16 more31 min
Mar 26, 9:39 AM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 25 more5 hr
Mar 26, 12:43 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brazoria, Calhoun, DeWitt and 11 more62 min
Mar 26, 12:57 PM CDTSevere Thunderstorm WatchSPCAransas, Bee, Brazoria, Calhoun, Chambers, Duval and 17 more6 hr
Mar 26, 3:06 PM CDTMesoscale DiscussionSPCHardin, Jasper, Jefferson, Newton, Orange, Tyler54 min
Mar 26, 3:51 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 8 more54 min
Mar 26, 3:57 PM CDTTornado WatchSPCAngelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 6 more7 hr
Mar 26, 4:52 PM CDTMesoscale DiscussionSPCArcher, Clay, Comanche, Eastland, Erath, Hamilton and 9 more83 min
Mar 26, 6:32 PM CDTMesoscale DiscussionSPCDallam4 hr
Mar 26, 6:56 PM CDTMesoscale DiscussionSPCAngelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 6 more94 min

Nearby

Tornado Watches in Texas, 2009Every tornado watch 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.