Alert archive / Texas / Tornado Watches in 2003

Tornado Watch 973

November 26, 2003Caddo Parish, Louisiana; 33 counties in Texas

The Storm Prediction Center issued this tornado watch at Nov 26, 2003, 1:45 PM CST for Caddo Parish, Louisiana; 33 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Nov 26, 2003, 1:45 PM CST (19:45 UTC)
Expired
Nov 26, 2003, 7:00 PM CST
In force
5 hr
Issued by
the Storm Prediction Center
All 34 counties

Caddo Parish, LA, Angelina County, TX, Austin County, TX, Brazoria County, TX, Brazos County, TX, Chambers County, TX, Cherokee County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Houston County, TX, Jasper County, TX, Jefferson County, TX, Leon County, TX, Liberty County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Nacogdoches County, TX, Orange County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 140 km from the middle of the area, began a volume at 19:48 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.

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 12:00Z, 7.8 hours before the alert went out and 216 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 12:00Z on 2003-11-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2003-11-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 309 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
704 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
309 m²/s²
0-3 km storm-relative helicity
351 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 261954
SEL3  
SPC WW 261945
TXZ000-CWZ000-270100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 973 
NWS STORM PREDICTION CENTER NORMAN OK 
145 PM CST WED NOV 26 2003

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

       SOUTHEAST AND EAST CENTRAL TEXAS
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 145 PM UNTIL
700 PM CST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 65 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 105 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 50 MILES SOUTH OF COLLEGE STATION TEXAS TO 55
MILES EAST OF LUFKIN 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.




DISCUSSION...ISOLATED CONVECTIVE ELEMENTS WERE INCREASING
ALONG/AHEAD OF LOW LEVEL CONFLUENCE AXIS WSW OF HOU. STRONG LOW
LEVEL MOISTURE INFLOW AND A FEW MORE HOURS OF SURFACE HEATING SHOULD
ALLOW CAPPING INVERSION TO ERODE SUFFICIENTLY FOR DEEP SURFACE-BASED
CONVECTION TO INCREASE. IN ADDITION...APPROACH OF UPSTREAM SHORT
WAVE TROUGH WILL FURTHER AID ASCENT AND DESTABILIZATION ACROSS THE
REGION. SSELY LOW LEVEL FLOW TOPPED BY STRENGTHENING SWLY MID LEVEL
WINDS WILL RESULT IN FAVORABLE DEEP LAYER SHEAR FOR SUPERCELLS.
ABUNDANT BOUNDARY LAYER MOISTURE AND LOW LCL/LFC WILL LEAD TO
ENHANCED POTENTIAL FOR LOW LEVEL STORM ROTATION AND TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 55 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 24025.


...CORFIDI/CARBIN

312,0962 324,0934 294,0934 282,0962

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 26, 5:52 PM CSTMesoscale DiscussionSPCCaddo53 min
Nov 26, 1:16 PM CSTMesoscale DiscussionSPCAngelina, Austin, Brazoria, Chambers, Cherokee, Fort Bend and 18 more89 min

Nearby

Tornado Watches in Texas, 2003Tornado Watches in Louisiana, 2003Every tornado watch in 2003

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.