Alert archive / Texas / Tornado Watches in 2009

Tornado Watch 211

April 29, 200920 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 29, 2009, 2:33 PM CDT for 20 counties in Texas. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Apr 29, 2009, 2:33 PM CDT (19:33 UTC)
Expired
Apr 29, 2009, 11:51 PM CDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt

Counties Coke County, TX, Concho County, TX, Crockett County, TX, Edwards County, TX, Glasscock County, TX, Irion County, TX, Kimble County, TX, Kinney County, TX, Maverick County, TX, Menard County, TX, Pecos County, TX, Reagan County, TX, Runnels County, TX, Schleicher County, TX, Sterling County, TX, Sutton County, TX, Terrell County, TX, Tom Green County, TX, Upton County, TX, Val Verde County, TX

The radar

The San Angelo radar (KSJT), 95 km from the middle of the area, began a volume at 19:36 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
70%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 29, 2:43 PM CDTTornado WarningMAFPecos32 min
Apr 29, 3:10 PM CDTSevere Thunderstorm WarningMAFPecos, Terrell35 min
Apr 29, 3:11 PM CDTTornado WarningMAFPecos34 min
Apr 29, 3:37 PM CDTSevere Thunderstorm WarningMAFPecos, Terrell53 min
Apr 29, 3:44 PM CDTSevere Thunderstorm WarningMAFPecos31 min
Apr 29, 3:49 PM CDTTornado WarningMAFPecos, Terrell41 min
Apr 29, 4:21 PM CDTTornado WarningMAFPecos, Terrell54 min
Apr 29, 4:31 PM CDTSevere Thunderstorm WarningMAFPecos59 min
Apr 29, 4:52 PM CDTTornado WarningMAFTerrell53 min
Apr 29, 5:10 PM CDTSevere Thunderstorm WarningMAFPecos, Terrell65 min
Apr 29, 5:22 PM CDTTornado WarningMAFTerrell53 min
Apr 29, 5:35 PM CDTTornado WarningSJTCrockett55 min
Apr 29, 5:47 PM CDTTornado WarningEWXVal Verde43 min
Apr 29, 5:58 PM CDTTornado WarningMAFTerrell32 min
Apr 29, 6:22 PM CDTSevere Thunderstorm WarningMAFTerrell53 min
Apr 29, 6:25 PM CDTTornado WarningEWXVal Verde65 min
Apr 29, 6:53 PM CDTTornado WarningMAFTerrell52 min
Apr 29, 7:21 PM CDTTornado WarningEWXVal Verde39 min
Apr 29, 7:26 PM CDTSevere Thunderstorm WarningEWXVal Verde49 min
Apr 29, 7:58 PM CDTSevere Thunderstorm WarningEWXVal Verde32 min
Apr 29, 8:34 PM CDTSevere Thunderstorm WarningEWXEdwards, Val Verde26 min
Apr 29, 9:30 PM CDTSevere Thunderstorm WarningEWXVal Verde45 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

Midland Regional, TX (KMAF), launched 12:00Z, 7.6 hours before the alert went out and 130 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, Midland Regional, TX at 12:00Z on 2009-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2530 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, Midland Regional, TX at 12:00Z on 2009-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 162 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
2530 J/kg
Mixed-layer CIN
-66 J/kg
Mixed-layer LCL
526 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
162 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.7

Open this sounding in Storm Lab

The text

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

653 
WWUS20 KWNS 291932
SEL1  
SPC WW 291932
TXZ000-300300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 211
NWS STORM PREDICTION CENTER NORMAN OK
235 PM CDT WED APR 29 2009

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

       PARTS OF SOUTHWEST TEXAS

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 235 PM UNTIL
1000 PM 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 75 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 40 MILES NORTH NORTHWEST OF
DRYDEN TEXAS TO 40 MILES NORTH OF JUNCTION 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 209...WW 210...

DISCUSSION...SEVERE THUNDERSTORMS EXPECTED TO DEVELOP ON DRY LINE
WRN PORTION OF WW AND MOVE SLOWLY E.  WITH MLCAPES TO 3000 J/KG AND
FAVORABLE VEERING SHEAR PROFILES...SUPERCELLS EXPECTED TO BE PRIMARY
MODE.  VERY LARGE HAIL AND POSSIBLE TORNADOES WILL BE ASSOCIATED
WITH ANY SUPERCELL THAT DEVELOPS.

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
550. MEAN STORM MOTION VECTOR 25020.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 7:23 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Callahan and 61 more3 hr
Apr 28, 7:46 PM CDTMesoscale DiscussionSPCLoving, Pecos, Reeves, Ward, Winkler119 min
Apr 28, 9:25 PM CDTSevere Thunderstorm WatchSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 43 more6 hr
Apr 28, 10:33 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Briscoe, Carson, Castro and 48 more87 min
Apr 28, 10:57 PM CDTSevere Thunderstorm WatchSPCAndrews, Dawson, Ector, Gaines, Loving, Martin and 2 more5 hr
Apr 29, 2:46 AM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 27 more89 min
Apr 29, 3:49 AM CDTSevere Thunderstorm WatchSPCArcher, Armstrong, Baylor, Briscoe, Carson, Childress and 19 more7 hr
Apr 29, 6:09 AM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Clay, Collingsworth, Cottle and 6 more96 min
Apr 29, 9:16 AM CDTMesoscale DiscussionSPCArcher, Baylor, Bowie, Camp, Cass, Clay and 26 more89 min
Apr 29, 9:36 AM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Collin, Cooke, Delta and 14 more6 hr
Apr 29, 12:07 PM CDTMesoscale DiscussionSPCBorden, Bosque, Callahan, Coke, Coleman, Comanche and 33 more113 min
Apr 29, 12:36 PM CDTTornado WatchSPCArcher, Baylor, Borden, Callahan, Clay, Crosby and 32 more9 hr
Apr 29, 12:58 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Delta, Fannin and 8 more2 hr
Apr 29, 2:03 PM CDTMesoscale DiscussionSPCCoke, Crockett, Glasscock, Irion, Midland, Reagan and 3 more57 min
Apr 29, 2:59 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Donley, Floyd, Gray and 7 more91 min
Apr 29, 3:04 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Dallas, Delta and 17 more56 min
Apr 29, 3:27 PM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Collin, Cooke, Dallas and 24 more6 hr
Apr 29, 3:34 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Callahan, Clay, Crosby and 31 more56 min
Apr 29, 3:47 PM CDTTornado WatchSPCArmstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 18 more7 hr
Apr 29, 5:17 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 18 more88 min
Apr 29, 5:19 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Delta and 21 more116 min
Apr 29, 5:53 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Dallas and 20 more67 min
Apr 29, 6:21 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Callahan, Clay, Crosby and 33 more54 min

Nearby

Tornado Watches in Texas, 2009Every tornado watch in 2009

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.