Alert archive / Texas / Tornado Watches in 2007

Tornado Watch 200

April 29, 200724 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 29, 2007, 7:48 PM CDT for 24 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 29, 2007, 7:48 PM CDT (00:48 UTC)
Expired
Apr 30, 2007, 3:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 24 counties

Bandera County, TX, Brewster County, TX, Crane County, TX, Crockett County, TX, Dimmit County, TX, Edwards County, TX, Frio County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, La Salle County, TX, Maverick County, TX, Medina County, TX, Pecos County, TX, Reagan County, TX, Real County, TX, Schleicher County, TX, Sutton County, TX, Terrell County, TX, Upton County, TX, Uvalde County, TX, Val Verde County, TX, Webb County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 62 km from the middle of the area, began a volume at 00:52 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 29, 7:53 PM CDTTornado WarningMAFUpton67 min
Apr 29, 8:02 PM CDTSevere Thunderstorm WarningMAFBrewster58 min
Apr 29, 8:27 PM CDTSevere Thunderstorm WarningMAFReagan63 min
Apr 29, 8:35 PM CDTSevere Thunderstorm WarningMAFPecos55 min
Apr 29, 9:22 PM CDTSevere Thunderstorm WarningMAFPecos38 min
Apr 29, 9:29 PM CDTFlash Flood WarningMAFPecos3 hr
Apr 29, 9:41 PM CDTSevere Thunderstorm WarningMAFTerrell64 min
Apr 29, 10:02 PM CDTTornado WarningEWXMaverick58 min
Apr 29, 10:27 PM CDTSevere Thunderstorm WarningMAFTerrell63 min
Apr 29, 10:42 PM CDTTornado WarningEWXMaverick33 min
Apr 29, 11:14 PM CDTSevere Thunderstorm WarningEWXMaverick21 min
Apr 29, 11:43 PM CDTFlash Flood WarningEWXVal Verde4 hr
Apr 29, 11:53 PM CDTSevere Thunderstorm WarningMAFPecos67 min
Apr 30, 1:26 AM CDTSevere Thunderstorm WarningMAFPecos49 min
Apr 30, 1:55 AM CDTSevere Thunderstorm WarningEWXVal Verde65 min
Apr 30, 2:11 AM CDTSevere Thunderstorm WarningEWXEdwards64 min
Apr 30, 2:40 AM CDTFlash Flood WarningEWXEdwards4 hr
Apr 30, 2:59 AM CDTSevere Thunderstorm WarningEWXKinney, Val Verde61 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, 0.8 hours before the alert went out and 22 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 2007-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1523 joules per kilogram.LCLLFCEL10008507005003002001001 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 2007-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 square meters per square second.193958Sfc1 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
1523 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
1447 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
182 m²/s²
Significant tornado parameter
0.7
Supercell composite
6.7

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 300051
SEL0  
SPC WW 300051
TXZ000-300800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 200
NWS STORM PREDICTION CENTER NORMAN OK
745 PM CDT SUN APR 29 2007

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

       SOUTHWEST TEXAS

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 745 PM UNTIL
300 AM CDT.

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 APPROXIMATELY ALONG AND 55 STATUTE
MILES EITHER SIDE OF A LINE FROM 20 MILES SOUTH SOUTHWEST OF
HONDO TEXAS TO 60 MILES NORTHWEST OF DRYDEN TEXAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).

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 TORNADO
WATCH NUMBER 198. WATCH NUMBER 198 WILL NOT BE IN EFFECT AFTER
745 PM CDT. CONTINUE...WW 199...

DISCUSSION...WARM/MOIST AND VERY UNSTABLE AIR MASS FROM THE
TRANS-PECOS REGION SEWD ALONG THE RIO GRANDE VALLEY AND SRN EDGE OF
THE EDWARDS PLATEAU IS EXPECTED TO SUPPORT A CONTINUATION OF STRONG
TO SEVERE TSTMS TONIGHT. THIS ACTIVITY WILL BE FURTHER SUSTAINED AS
LARGE SCALE DIFFLUENCE...AHEAD OF AN UPPER LOW...SPREADS EWD ATOP
THE UNSTABLE WARM SECTOR. LOW LEVEL SELY FLOW TOPPED BY
STRENGTHENING WLY FLOW ALOFT WILL CONTRIBUTE TO SHEAR PROFILES
FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. TORNADO POTENTIAL WILL
ALSO EXIST GIVEN ABUNDANT LOW LEVEL MOISTURE AND LOW LEVEL
DIRECTIONAL SHEAR.

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 23020.


...CARBIN/HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 7:25 PM CDTMesoscale DiscussionSPCBrewster, Crane, Crockett, Culberson, Jeff Davis, Loving and 11 more65 min
Apr 29, 8:35 PM CDTMesoscale DiscussionSPCBaylor, Callahan, Coke, Coleman, Concho, Ector and 24 more115 min
Apr 29, 10:42 PM CDTMesoscale DiscussionSPCBandera, Brewster, Crane, Crockett, Dimmit, Edwards and 18 more63 min
Apr 30, 2:10 AM CDTMesoscale DiscussionSPCBandera, Crockett, Dimmit, Edwards, Frio, Kerr and 12 more95 min
Apr 30, 2:47 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 10 more3 hr
Apr 30, 2:51 AM CDTSevere Thunderstorm WatchSPCBandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 9 more5 hr
Apr 30, 4:46 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 9 more119 min
Apr 30, 12:37 PM CDTMesoscale DiscussionSPCAtascosa, Bastrop, Bee, Caldwell, DeWitt, Dimmit and 15 more83 min
Apr 30, 1:22 PM CDTMesoscale DiscussionSPCCamp, Collin, Dallas, Delta, Fannin, Franklin and 14 more113 min
Apr 30, 1:26 PM CDTSevere Thunderstorm WatchSPCAustin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 10 more7 hr
Apr 30, 3:01 PM CDTTornado WatchSPCDimmit, Duval, Frio, Jim Wells, La Salle, Live Oak and 4 more7 hr
Apr 30, 3:23 PM CDTMesoscale DiscussionSPCGrimes, Harris, Houston, Leon, Liberty, Madison and 4 more97 min
Apr 30, 5:38 PM CDTMesoscale DiscussionSPCArcher, Armstrong, Baylor, Borden, Briscoe, Callahan and 42 more2 hr
Apr 30, 6:18 PM CDTMesoscale DiscussionSPCDimmit, Duval, Frio, Jim Wells, La Salle, Live Oak and 4 more57 min
Apr 30, 6:37 PM CDTMesoscale DiscussionSPCAustin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 10 more83 min

Nearby

Tornado Watches in Texas, 2007Every tornado watch in 2007

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.