Alert archive / Texas / Tornado Watches in 2002

Tornado Watch 810

December 30, 200239 counties in Texas

The Storm Prediction Center issued this tornado watch at Dec 30, 2002, 1:30 PM CST for 39 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 30, 2002, 1:30 PM CST (19:30 UTC)
Expired: Dec 30, 2002, 7:00 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 39 counties

Anderson County, TX, Bell County, TX, Bosque County, TX, Camp County, TX, Collin County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Grayson County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Lampasas County, TX, Leon County, TX, Limestone County, TX, McLennan County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 66 km from the middle of the area, began a volume at 19:30 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

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

Issued	Product	Office	Counties	Lasted
Dec 30, 1:44 PM CST	Severe Thunderstorm Warning	FWD	Bosque, Hill	46 min
Dec 30, 1:49 PM CST	Tornado Warning	FWD	Ellis, Hill	26 min
Dec 30, 2:11 PM CST	Severe Thunderstorm Warning	FWD	Coryell, McLennan	64 min
Dec 30, 2:12 PM CST	Severe Thunderstorm Warning	FWD	Dallas	48 min
Dec 30, 2:13 PM CST	Tornado Warning	FWD	Ellis	47 min
Dec 30, 2:19 PM CST	Tornado Warning	FWD	Dallas	41 min
Dec 30, 2:23 PM CST	Severe Thunderstorm Warning	FWD	Collin	37 min
Dec 30, 2:30 PM CST	Severe Thunderstorm Warning	FWD	Hill, Navarro	60 min
Dec 30, 2:36 PM CST	Flash Flood Warning	FWD	Collin, Dallas	84 min
Dec 30, 2:36 PM CST	Severe Thunderstorm Warning	FWD	Bell	39 min
Dec 30, 2:57 PM CST	Severe Thunderstorm Warning	FWD	Ellis	33 min
Dec 30, 3:28 PM CST	Severe Thunderstorm Warning	FWD	Henderson, Kaufman, Navarro, Van Zandt	62 min
Dec 30, 3:48 PM CST	Severe Thunderstorm Warning	FWD	Bell	42 min
Dec 30, 4:11 PM CST	Severe Thunderstorm Warning	SHV	Red River	34 min
Dec 30, 4:16 PM CST	Severe Thunderstorm Warning	FWD	Bell, Falls, Limestone	59 min
Dec 30, 4:36 PM CST	Severe Thunderstorm Warning	FWD	Henderson, Van Zandt	39 min
Dec 30, 5:11 PM CST	Severe Thunderstorm Warning	SHV	Smith	64 min
Dec 30, 5:23 PM CST	Severe Thunderstorm Warning	FWD	Freestone	22 min
Dec 30, 6:34 PM CST	Severe Thunderstorm Warning	FWD	Bell, Milam	26 min

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 7.5 hours before the alert went out and 91 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: 966 J/kg
Mixed-layer CIN: -128 J/kg
Mixed-layer LCL: 575 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 1.5

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 301928
SEL0  
SPC WW 301930
TXZ000-310100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 810
STORM PREDICTION CENTER NORMAN OK
130 PM CST MON DEC 30 2002

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

   CENTRAL AND NORTHEAST TEXAS                              

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 700
PM CST.

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

THE TORNADO WATCH AREA IS ALONG AND 80 STATUTE MILES EAST AND WEST
OF A LINE FROM 20 MILES EAST SOUTHEAST OF TEMPLE TEXAS TO 80 MILES
NORTHEAST OF DALLAS 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 SEVERE
THUNDERSTORM WATCH NUMBER 808.  WATCH NUMBER 808 WILL NOT BE IN
EFFECT AFTER 130 PM CST.  CONTINUE...WW 809...

DISCUSSION...PRESSURE FALLS CONTINUE TO OVERSPREAD WW EARLY THIS
AFTERNOON...UNDER STRONG MID/UPPER LEVEL WIND FIELDS.  18Z SOUNDING
FROM FTW INDICATED FAVORABLE SUPERCELL ENVIRONMENT...WITH POTENTIAL
FOR A FEW TORNADOES GIVEN THE LOW LCLS AND STRONG LOW LEVEL SHEAR. 
BEST TORNADIC POTENTIAL WILL LIKELY DEVELOP ALONG AND SOUTH OF WARM
FRONT DEVELOPING NEAR I-20.


AVIATION...TORNADOES AND 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 24035.


...EVANS

310,0982 333,0971 333,0942 310,0954

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, 12:00 PM CST	Tornado Watch	SPC	Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 21 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; radar from the NEXRAD Level II archive.