Alert archive / Texas / Tornado Watches in 2002

Tornado Watch 809

December 30, 200227 counties in Texas

The Storm Prediction Center issued this tornado watch at Dec 30, 2002, 12:00 PM CST for 27 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 30, 2002, 12:00 PM CST (18:00 UTC)
Expired: Dec 30, 2002, 6:00 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 27 counties

Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Frio County, TX, Gillespie County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kimble 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

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 30, 1:26 PM CST	Severe Thunderstorm Warning	EWX	Kerr, Real	64 min
Dec 30, 1:48 PM CST	Severe Thunderstorm Warning	EWX	Burnet, Williamson	42 min
Dec 30, 1:53 PM CST	Severe Thunderstorm Warning	EWX	Medina	37 min
Dec 30, 1:57 PM CST	Severe Thunderstorm Warning	EWX	Bexar	63 min
Dec 30, 2:05 PM CST	Tornado Warning	EWX	Bexar	55 min
Dec 30, 2:26 PM CST	Tornado Warning	EWX	Comal	64 min
Dec 30, 3:05 PM CST	Tornado Warning	EWX	Hays	55 min
Dec 30, 3:18 PM CST	Tornado Warning	EWX	Caldwell	57 min
Dec 30, 3:28 PM CST	Severe Thunderstorm Warning	EWX	Bexar	62 min
Dec 30, 3:29 PM CST	Severe Thunderstorm Warning	EWX	Travis	61 min
Dec 30, 3:50 PM CST	Severe Thunderstorm Warning	EWX	Guadalupe	55 min
Dec 30, 3:53 PM CST	Severe Thunderstorm Warning	EWX	Comal	52 min
Dec 30, 3:58 PM CST	Tornado Warning	EWX	Bastrop	62 min
Dec 30, 3:59 PM CST	Severe Thunderstorm Warning	EWX	Williamson	61 min
Dec 30, 4:22 PM CST	Tornado Warning	EWX	Williamson	53 min
Dec 30, 4:40 PM CST	Severe Thunderstorm Warning	FWD	Milam	65 min
Dec 30, 5:11 PM CST	Tornado Warning	EWX	Bastrop, Fayette, Lee	64 min
Dec 30, 5:12 PM CST	Severe Thunderstorm Warning	FWD	Milam	33 min

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 6.0 hours before the alert went out and 161 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 333 J/kg
Mixed-layer CIN: -495 J/kg
Mixed-layer LCL: 1056 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 269 m²/s²
0-3 km storm-relative helicity: 311 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 301800
SEL9  
SPC WW 301800
TXZ000-310000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 809
STORM PREDICTION CENTER NORMAN OK
1200 PM CST MON DEC 30 2002

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

   CENTRAL TEXAS                              

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM NOON CST UNTIL 600
PM CST.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 85 STATUTE MILES EAST AND WEST
OF A LINE FROM 15 MILES WEST OF COTULLA TEXAS TO 55 MILES NORTH
NORTHWEST OF AUSTIN 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...  CONTINUE...WW 808...

DISCUSSION...SEVERE THUNDERSTORMS...INCLUDING SUPERCELLS...WILL
LIKELY FORM QUICKLY ACROSS CENTRAL TX IN THE NEXT COUPLE OF HOURS
AS CAP BREAKS AND SURFACE FRONT PROGRESSES EWD.  THOUGH STORMS WILL
LIKELY EVOLVE INTO A LINE...STRONG LOW LEVEL SHEAR WILL SUPPORT A
THREAT OF TORNADOES...ALONG WITH DAMAGING WINDS AND VERY LARGE
HAIL.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24035.


...EVANS

310,0963 282,0980 282,1005 310,0992

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 30, 10:55 AM CST	Severe Thunderstorm Watch	SPC	Bosque, Collin, Comanche, Cooke, Coryell, Dallas and 25 more	5 hr
Dec 30, 1:30 PM CST	Tornado Watch	SPC	Anderson, Bell, Bosque, Camp, Collin, Cooke and 33 more	6 hr
Dec 30, 2:50 PM CST	Tornado Watch	SPC	Aransas, Bee, Calhoun, Duval, Goliad, Jim Wells and 9 more	6 hr
Dec 30, 3:20 PM CST	Tornado Watch	SPC	Anderson, Angelina, Austin, Brazoria, Brazos, Chambers and 29 more	6 hr
Dec 30, 4:35 PM CST	Severe Thunderstorm Watch	SPC	Brooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Starr and 2 more	5 hr

Nearby

Tornado Watches in Texas, 2002 Every 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.