Alert archive / Texas / Tornado Watches in 2007

Tornado Watch 203

April 30, 200710 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 30, 2007, 3:01 PM CDT for 10 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 30, 2007, 3:01 PM CDT (20:01 UTC)
Expired
Apr 30, 2007, 9:48 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Dimmit County, TX, Duval County, TX, Frio County, TX, Jim Wells County, TX, La Salle County, TX, Live Oak County, TX, Maverick County, TX, McMullen County, TX, Webb County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 171 km from the middle of the area, began a volume at 20:03 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
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 30, 4:27 PM CDTSevere Thunderstorm WarningCRPMcMullen63 min
Apr 30, 4:46 PM CDTTornado WarningCRPMcMullen29 min
Apr 30, 4:53 PM CDTFlash Flood WarningCRPMcMullen97 min
Apr 30, 5:13 PM CDTTornado WarningCRPDuval, McMullen47 min
Apr 30, 5:33 PM CDTFlash Flood WarningCRPDuval87 min
Apr 30, 5:58 PM CDTTornado WarningCRPDuval62 min
Apr 30, 6:58 PM CDTTornado WarningCRPDuval62 min
Apr 30, 7:22 PM CDTSevere Thunderstorm WarningCRPWebb53 min
Apr 30, 8:02 PM CDTSevere Thunderstorm WarningCRPDuval32 min
Apr 30, 8:14 PM CDTTornado WarningCRPWebb46 min
Apr 30, 9:01 PM CDTSevere Thunderstorm WarningCRPWebb44 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

Corpus Christi, TX (KCRP), launched 12:00Z, 8.0 hours before the alert went out and 198 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, Corpus Christi, TX at 12:00Z on 2007-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2122 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, Corpus Christi, TX at 12:00Z on 2007-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
2122 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
471 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 302004
SEL3  
SPC WW 302004
TXZ000-010300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 203
NWS STORM PREDICTION CENTER NORMAN OK
300 PM CDT MON APR 30 2007

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

       SOUTH CENTRAL TEXAS

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 300 PM UNTIL
1000 PM CDT.

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 APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES EAST SOUTHEAST OF
LAREDO TEXAS TO 60 MILES NORTHWEST OF COTULLA TEXAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).

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 202...

DISCUSSION...TSTMS ARE EXPECTED TO BECOME INCREASINGLY NUMEROUS THIS
AFTERNOON INTO EVENING ALONG AND S OF OUTFLOW BOUNDARY STALLING
ACROSS THE AREA.  OTHER STORMS DEVELOPING ALONG THE HIGHER TERRAIN
OF NERN MEXICO MAY ALSO CROSS THE INTERNATIONAL BORDER BY LATE
AFTERNOON OR EVENING. COMBINATION OF MLCAPES OF 2000-3000 J/KG AND
40-45 KT OF EFFECTIVE BULK SHEAR INDICATE THE POTENTIAL FOR
SUPERCELLS CAPABLE OF LARGE HAIL.  ISOLATED TORNADOES WILL ALSO BE
POSSIBLE...ESPECIALLY WITH ANY MATURE STORMS THAT FAVORABLY INTERACT
WITH OUTFLOW BOUNDARY WHERE LOW-LEVEL SHEAR WILL BE ENHANCED.

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 29020.


...MEAD/THOMPSON

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, 7:48 PM CDTTornado WatchSPCBandera, Brewster, Crane, Crockett, Dimmit, Edwards and 18 more7 hr
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, 3:23 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.