Alert archive / Texas / Tornado Watches in 2006

Tornado Watch 821

October 10, 200626 counties in Texas

The Storm Prediction Center issued this tornado watch at Oct 10, 2006, 6:43 AM CDT for 26 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Oct 10, 2006, 6:43 AM CDT (11:43 UTC)
Expired
Oct 10, 2006, 2:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 26 counties

Anderson County, TX, Austin County, TX, Bastrop County, TX, Brazos County, TX, Burleson County, TX, Caldwell County, TX, Colorado County, TX, Comal County, TX, Fayette County, TX, Freestone County, TX, Grimes County, TX, Hays County, TX, Houston County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Milam County, TX, Montgomery County, TX, Polk County, TX, Robertson County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX, Waller County, TX, Washington County, TX

The radar

The Ft Hood radar (KGRK), 74 km from the middle of the area, began a volume at 11:43 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
10%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 10, 9:17 AM CDTSevere Thunderstorm WarningEWXHays58 min
Oct 10, 9:25 AM CDTFlash Flood WarningFWDRobertson3 hr
Oct 10, 9:45 AM CDTTornado WarningHGXBurleson30 min
Oct 10, 10:18 AM CDTTornado WarningHGXBrazos, Burleson42 min
Oct 10, 10:33 AM CDTSevere Thunderstorm WarningHGXWashington42 min
Oct 10, 11:36 AM CDTTornado WarningHGXWaller, Washington39 min
Oct 10, 12:38 PM CDTSevere Thunderstorm WarningHGXHarris, Montgomery52 min
Oct 10, 1:19 PM CDTSevere Thunderstorm WarningHGXHarris, Montgomery41 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

Fort Worth, TX (KFWD), launched 00:00Z, 11.7 hours before the alert went out and 238 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, Fort Worth, TX at 00:00Z on 2006-10-10Temperature 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, Fort Worth, TX at 00:00Z on 2006-10-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 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
2676 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
81 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 101141
SEL1  
SPC WW 101141
TXZ000-101900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 821
NWS STORM PREDICTION CENTER NORMAN OK
640 AM CDT TUE OCT 10 2006

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

       CENTRAL TEXAS

EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 640 AM UNTIL
200 PM CDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH OF HUNTSVILLE
TEXAS TO 15 MILES EAST SOUTHEAST OF NEW BRAUNFELS TEXAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU1).

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 820...

DISCUSSION...TSTMS/SUPERCELLS EXPECTED TO PERSIST INVOF STALLED
OUTFLOW BOUNDARY AND FRONT OVER THE TX HILL COUNTRY.  THIS ACTIVITY
SHOULD MOVE/DEVELOP E TOWARD THE MIDDLE TX CSTL PLN AS SURFACE
HEATING OCCURS AND THE LOWER LEVELS CONTINUE TO MOISTEN.  GIVEN RICH
BOUNDARY LAYER MOISTURE AND MODERATE LOW LEVEL DIRECTIONAL
SHEAR...POTENTIAL WILL EXIST FOR ISOLATED TORNADOES UNTIL LOW LEVEL
FLOW VEERS LATER IN THE DAY.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 25035.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 9, 7:44 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Culberson, Dawson, Ector and 15 more91 min
Oct 9, 10:44 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Comanche, Concho and 20 more2 hr
Oct 9, 11:17 PM CDTSevere Thunderstorm WatchSPCCoke, Concho, Crockett, Edwards, Irion, Kimble and 7 more6 hr
Oct 10, 1:43 AM CDTMesoscale DiscussionSPCBandera, Brewster, Crockett, Edwards, Gillespie, Kendall and 13 more92 min
Oct 10, 3:18 AM CDTTornado WatchSPCBandera, Bell, Blanco, Burnet, Coryell, Crockett and 20 more7 hr
Oct 10, 5:00 AM CDTMesoscale DiscussionSPCAustin, Bandera, Bastrop, Bell, Bexar, Blanco and 49 more90 min
Oct 10, 8:52 AM CDTMesoscale DiscussionSPCBandera, Bell, Bexar, Blanco, Burnet, Comal and 27 more83 min
Oct 10, 9:31 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Brazos, Burleson and 32 more119 min
Oct 10, 11:28 AM CDTMesoscale DiscussionSPCAngelina, Austin, Brazoria, Brazos, Colorado, Fayette and 15 more92 min
Oct 10, 11:48 AM CDTTornado WatchSPCBrazoria, Calhoun, Chambers, Fort Bend, Galveston, Hardin and 8 more5 hr
Oct 10, 12:34 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 14 more56 min
Oct 10, 1:39 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 12 more96 min
Oct 10, 3:08 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Galveston, Jefferson and 4 more97 min

Nearby

Tornado Watches in Texas, 2006Every tornado watch in 2006

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.