Alert archive / Texas / Tornado Watches in 2007

Tornado Watch 253

May 7, 200714 counties in Texas

The Storm Prediction Center issued this tornado watch at May 7, 2007, 5:59 PM CDT for 14 counties in Texas. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 7, 2007, 5:59 PM CDT (22:59 UTC)
Expired
May 8, 2007, 2:00 AM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt

Counties Bandera County, TX, Dimmit County, TX, Edwards County, TX, Frio County, TX, Kerr County, TX, Kinney County, TX, La Salle County, TX, Maverick County, TX, Medina County, TX, Real County, TX, Uvalde County, TX, Val Verde County, TX, Webb County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 45 km from the middle of the area, began a volume at 23:00 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
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 7, 6:06 PM CDTFlash Flood WarningEWXKinney, Maverick3 hr
May 7, 7:05 PM CDTFlash Flood WarningEWXEdwards, Real4 hr
May 7, 7:57 PM CDTFlash Flood WarningEWXDimmit3 hr
May 7, 8:12 PM CDTFlash Flood WarningEWXUvalde, Zavala3 hr
May 7, 8:50 PM CDTSevere Thunderstorm WarningEWXDimmit25 min
May 7, 11:01 PM CDTTornado WarningCRPWebb29 min
May 7, 11:15 PM CDTFlash Flood WarningCRPWebb90 min
May 7, 11:29 PM CDTSevere Thunderstorm WarningCRPWebb61 min
May 7, 11:56 PM CDTSevere Thunderstorm WarningCRPLa Salle64 min
May 8, 1:00 AM CDTSevere Thunderstorm WarningCRPLa Salle30 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 12:00Z, 11.0 hours before the alert went out and 100 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 12:00Z on 2007-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3147 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 12:00Z on 2007-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 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
3147 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
532 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
1.7
Supercell composite
7.5

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 072300
SEL3  
SPC WW 072300
TXZ000-080700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 253
NWS STORM PREDICTION CENTER NORMAN OK
600 PM CDT MON MAY 7 2007

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

       SOUTH TEXAS

EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 600 PM UNTIL
200 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 80 STATUTE
MILES EITHER SIDE OF A LINE FROM 5 MILES EAST NORTHEAST OF HONDO
TEXAS TO 50 MILES SOUTH SOUTHEAST OF DEL RIO 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.

DISCUSSION...SUPERCELLS AND SUPERCELL CLUSTERS THAT FORMED IN THE
HIGHER TERRAIN W OF THE RIO GRANDE EXPECTED TO MOVE/DEVELOP SLOWLY E
INTO 20+ KT CURRENT OF VERY MOIST ESELY LOW LEVEL FLOW.  WHILE DEEP
SHEAR IS MARGINAL FOR SUPERCELL DEVELOPMENT IN LOWER TERRAIN GIVEN
CIN... STRONGLY BACK LOW LEVEL WINDS SUGGEST TORNADO POTENTIAL WITH
ANY STORMS THAT DO MOVE/DEVELOP E INTO THIS ENVIRONMENT.

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
600. MEAN STORM MOTION VECTOR 26015.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 7:04 PM CDTMesoscale DiscussionSPCCrockett, Irion, Reagan, Terrell, Upton56 min
May 6, 7:55 PM CDTTornado WatchSPCCoke, Coleman, Concho, Crockett, Glasscock, Howard and 13 more6 hr
May 6, 10:20 PM CDTMesoscale DiscussionSPCConcho, Irion, Reagan, Tom Green55 min
May 6, 11:04 PM CDTMesoscale DiscussionSPCArcher, Clay, Cooke, Fannin, Grayson, Lamar and 3 more56 min
May 6, 11:54 PM CDTTornado WatchSPCArcher, Baylor, Clay, Wichita, Wilbarger5 hr
May 7, 4:30 AM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Wichita, Wilbarger30 min
May 7, 10:29 AM CDTMesoscale DiscussionSPCCollin, Cooke, Denton, Fannin, Grayson, Jack and 4 more2 hr
May 7, 10:51 AM CDTTornado WatchSPCCollin, Cooke, Denton, Fannin, Grayson, Lamar and 2 more5 hr
May 7, 1:14 PM CDTMesoscale DiscussionSPCCrockett, Edwards, Irion, Kimble, Kinney, Menard and 6 more61 min
May 7, 1:59 PM CDTMesoscale DiscussionSPCCrockett, Edwards, Irion, Kimble, Kinney, Menard and 6 more61 min
May 7, 5:38 PM CDTMesoscale DiscussionSPCDimmit, Kinney, Maverick, Uvalde, Zavala67 min
May 7, 6:19 PM CDTMesoscale DiscussionSPCBrewster, Crane, Ector, Jeff Davis, Midland, Pecos and 7 more86 min
May 7, 6:42 PM CDTTornado WatchSPCBrewster, Jeff Davis, Pecos, Presidio, Reeves, Terrell5 hr

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.