Alert archive / Texas / Tornado Watches in 2002

Tornado Watch 674

September 7, 200217 counties in Texas

The Storm Prediction Center issued this tornado watch at Sep 7, 2002, 6:15 AM CDT for 17 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Sep 7, 2002, 6:15 AM CDT (11:15 UTC)
Expired
Sep 7, 2002, 12:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center

Counties Atascosa County, TX, Austin County, TX, Bexar County, TX, Brazoria County, TX, Colorado County, TX, DeWitt County, TX, Fort Bend County, TX, Galveston County, TX, Gonzales County, TX, Guadalupe County, TX, Harris County, TX, Jackson County, TX, Karnes County, TX, Lavaca County, TX, Liberty County, TX, Wharton County, TX, Wilson County, TX

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 7, 11:09 AM CDTFlash Flood WarningEWXBexar111 min

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 11.3 hours before the alert went out and 185 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 2002-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 408 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 2002-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.1939Sfc1 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
408 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
1317 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 071115
SEL4  
SPC WW 071115
TXZ000-CWZ000-071700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 674
STORM PREDICTION CENTER NORMAN OK
615 AM CDT SAT SEP 7 2002

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

   SOUTH CENTRAL AND SOUTHEAST TEXAS                              
   COASTAL WATERS                     

EFFECTIVE THIS SATURDAY MORNING FROM 615 AM UNTIL NOON CDT.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 35 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 50 MILES SOUTHWEST OF SAN ANTONIO TEXAS TO 25
MILES NORTH OF GALVESTON TEXAS.

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 673.  WATCH NUMBER 673 WILL NOT BE IN EFFECT AFTER 615 AM
CDT.

DISCUSSION...MESOSCALE AREA OF LOW PRESSURE IS LOCATED 50 N VCT AND
IS EXPECTED TO TRACK WSWWD THROUGH THE MORNING WITH A POTENTIAL FOR
A FEW TORNADOES. OTHER TORNADOES ARE ALSO POSSIBLE IN CONVECTIVE
BANDS TO THE EAST OF THIS LOW...WHERE LOW LEVEL SHEAR/VORTICITY 
REMAINS STRONG. 

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH...EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 08015.

...IMY

293,0990 301,0944 291,0944 283,0990

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 6, 7:15 PM CDTTornado WatchSPCAustin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 9 more5 hr
Sep 6, 11:35 PM CDTTornado WatchSPCAustin, Brazoria, Chambers, Colorado, Fayette, Fort Bend and 10 more8 hr
Sep 7, 10:40 AM CDTTornado WatchSPCAustin, Brazos, Burleson, Chambers, Colorado, Fayette and 16 more5 hr

Nearby

Tornado Watches in Texas, 2002Every tornado watch in 2002

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.