Alert archive / Texas / Severe Thunderstorm Watches in 2003

Severe Thunderstorm Watch 9

February 21, 200332 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Feb 21, 2003, 4:10 AM CST for 32 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 21, 2003, 4:10 AM CST (10:10 UTC)
Expired
Feb 21, 2003, 10:00 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
All 32 counties

Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Fayette County, TX, Frio County, TX, Gillespie County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, Lee County, TX, Llano County, TX, Mason County, TX, Maverick County, TX, Medina County, TX, Milam County, TX, Real County, TX, Travis County, TX, Uvalde County, TX, Williamson County, TX, Wilson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 111 km from the middle of the area, began a volume at 10:12 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Feb 21, 4:39 AM CSTFlash Flood WarningEWXBlanco, Burnet3 hr
Feb 21, 4:47 AM CSTSevere Thunderstorm WarningEWXKendall, Kerr58 min
Feb 21, 6:01 AM CSTFlash Flood WarningEWXHays, Travis, Williamson4 hr
Feb 21, 6:38 AM CSTFlash Flood WarningEWXGillespie67 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

Del Rio, TX (KDRT), launched 00:00Z, 10.2 hours before the alert went out and 165 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, Del Rio, TX at 00:00Z on 2003-02-21Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 00:00Z on 2003-02-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
567 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
154 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.

539 
WWUS20 KWNS 211007
SEL9
SPC WW 211010
TXZ000-211600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 9
STORM PREDICTION CENTER NORMAN OK
410 AM CST FRI FEB 21 2003

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   CENTRAL TEXAS                              

EFFECTIVE THIS FRIDAY MORNING FROM 410 AM UNTIL 1000 AM CST.

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

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 95 STATUTE MILES
EAST AND WEST OF A LINE FROM 60 MILES SOUTH SOUTHWEST OF HONDO
TEXAS TO 35 MILES NORTH OF AUSTIN TEXAS.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.


DISCUSSION...THUNDERSTORMS ARE INCREASING IN COVERAGE AND INTENSITY
ACROSS CENTRAL TX.  THESE STORMS ARE AHEAD OF STRONG UPPER
TROUGH...AND IN REGION OF INCREASING ELEVATED INSTABILITY. 
ISOLATED SEVERE THUNDERSTORMS CAPABLE OF LARGE HAIL WILL BE
POSSIBLE THROUGH THE MID MORNING HOURS.

AVIATION...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 25035.

...HART

283,1010 304,0991 304,0960 283,0975

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 21, 1:43 AM CSTMesoscale DiscussionSPCChambers, Hardin, Jasper, Jefferson, Liberty, Newton and 1 more2 hr
Feb 21, 2:43 AM CSTMesoscale DiscussionSPCDimmit, Edwards, Frio, Kinney, La Salle, Maverick and 5 more3 hr
Feb 21, 3:53 AM CSTMesoscale DiscussionSPCAransas, Austin, Brazoria, Calhoun, Colorado, Fort Bend and 13 more3 hr
Feb 21, 4:25 AM CSTTornado WatchSPCAustin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 15 more6 hr
Feb 21, 5:58 AM CSTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more2 hr
Feb 21, 6:16 AM CSTMesoscale DiscussionSPCAustin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 17 more119 min
Feb 21, 9:02 AM CSTMesoscale DiscussionSPCAngelina, Brazoria, Chambers, Cherokee, Fort Bend, Galveston and 22 more58 min
Feb 21, 9:40 AM CSTTornado WatchSPCAngelina, Austin, Brazoria, Brazos, Burleson, Chambers and 25 more6 hr
Feb 21, 11:47 AM CSTMesoscale DiscussionSPCAngelina, Brazoria, Chambers, Fort Bend, Galveston, Grimes and 18 more118 min
Feb 21, 1:30 PM CSTMesoscale DiscussionSPCHardin, Harris, Jasper, Liberty, Montgomery, Newton and 3 more2 hr
Feb 21, 3:32 PM CSTMesoscale DiscussionSPCHardin, Jasper, Liberty, Newton, Orange, Tyler118 min
Feb 21, 3:40 PM CSTTornado WatchSPCAngelina, Chambers, Hardin, Jasper, Jefferson, Nacogdoches and 5 more6 hr
Feb 21, 5:50 PM CSTMesoscale DiscussionSPCAngelina, Chambers, Hardin, Jasper, Jefferson, Nacogdoches and 5 more115 min

Nearby

Severe Thunderstorm Watches in Texas, 2003Every severe thunderstorm 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.