Alert archive / Texas / Tornado Watches in 2008

Tornado Watch 734

July 23, 200826 counties in Texas

The Storm Prediction Center issued this tornado watch at Jul 23, 2008, 9:39 AM CDT for 26 counties in Texas. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Jul 23, 2008, 9:39 AM CDT (14:39 UTC)
Expired
Jul 23, 2008, 11:32 AM CDT
In force
113 min
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
90 kt
All 26 counties

Aransas County, TX, Bee County, TX, Brazoria County, TX, Brooks County, TX, Calhoun County, TX, Cameron County, TX, DeWitt County, TX, Duval County, TX, Goliad County, TX, Gonzales County, TX, Hidalgo County, TX, Jackson County, TX, Jim Wells County, TX, Karnes County, TX, Kenedy County, TX, Kleberg County, TX, Lavaca County, TX, Live Oak County, TX, Matagorda County, TX, Nueces County, TX, Refugio County, TX, San Patricio County, TX, Victoria County, TX, Wharton County, TX, Willacy County, TX, Wilson County, TX

What SPC expected

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

Two or more tornadoes
60%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
30%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 23, 9:39 AM CDTTornado WarningCRPNueces, San Patricio36 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

Corpus Christi, TX (KCRP), launched 12:00Z, 2.7 hours before the alert went out and 51 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 12:00Z on 2008-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 232 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 12:00Z on 2008-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 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
232 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
599 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
112 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 231443
SEL4  
SPC WW 231443
TXZ000-CWZ000-240000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 734
NWS STORM PREDICTION CENTER NORMAN OK
940 AM CDT WED JUL 23 2008

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

       SOUTH TEXAS
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY MORNING AND EVENING FROM 940 AM UNTIL
700 PM CDT.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 105 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE
MILES EAST AND WEST OF A LINE FROM BROWNSVILLE TEXAS TO 35 MILES
NORTH OF VICTORIA TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 732. WATCH NUMBER 732 WILL NOT BE IN EFFECT AFTER
940 AM CDT. 

DISCUSSION...CENTER OF HURRICANE DOLLY FCST BY NHC TO MOVE INLAND
AND ACROSS LOWER VALLEY REGION OF DEEP S TX.  TORNADO PROBABILITIES
WILL INCREASE WITH OUTWARD EXTENT FROM CORE REGION INTO AREA OF GALE
WINDS...N THROUGH NE OF CENTER.  THIS TREND WILL RESULT FROM
COMBINATION OF MORE FAVORABLE KINEMATIC GEOMETRY...0-1 KM
SHEAR...AND INCREASING CAPE FROM POCKETS OF STRONGER SFC HEATING IN
OUTER PARTS OF CYCLONE CIRCULATION.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 90 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 10045.


...EDWARDS/HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 22, 10:27 PM CDTTornado WatchSPCBrooks, Cameron, Hidalgo, Kenedy, Kleberg, Nueces and 1 more11 hr
Jul 23, 6:56 AM CDTMesoscale DiscussionSPCCalhoun, Cameron, Hidalgo, Kenedy, Matagorda, Willacy94 min
Jul 23, 9:00 AM CDTMesoscale DiscussionSPCAransas, Bee, Brooks, Calhoun, Cameron, Goliad and 12 more60 min
Jul 23, 11:27 AM CDTTornado WatchSPCAransas, Bee, Brooks, Calhoun, Cameron, DeWitt and 19 more8 hr
Jul 23, 1:28 PM CDTMesoscale DiscussionSPCAransas, Bee, Brooks, Calhoun, Cameron, DeWitt and 16 more2 hr
Jul 23, 3:52 PM CDTMesoscale DiscussionSPCAransas, Bee, Brooks, Calhoun, DeWitt, Duval and 14 more113 min
Jul 23, 5:38 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brooks, Calhoun, Duval and 15 more97 min

Nearby

Tornado Watches in Texas, 2008Every tornado watch in 2008

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.