Alert archive / Texas / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 287

May 12, 201113 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 12, 2011, 3:18 AM CDT for 13 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 12, 2011, 3:18 AM CDT (08:18 UTC)
Expired
May 12, 2011, 7:58 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 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, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 25 km from the middle of the area, began a volume at 08:22 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
20%
One or more EF2 to EF5 tornadoes
5%
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
70%
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 12, 3:28 AM CDTSevere Thunderstorm WarningEWXVal Verde47 min
May 12, 4:20 AM CDTSevere Thunderstorm WarningEWXVal Verde40 min
May 12, 5:05 AM CDTSevere Thunderstorm WarningEWXVal Verde40 min
May 12, 5:24 AM CDTFlash Flood WarningEWXVal Verde3 hr
May 12, 5:46 AM CDTSevere Thunderstorm WarningEWXEdwards, Kinney, Val Verde44 min
May 12, 6:30 AM CDTSevere Thunderstorm WarningEWXEdwards, Kinney, Uvalde60 min
May 12, 6:40 AM CDTTornado WarningEWXKinney35 min
May 12, 6:59 AM CDTSevere Thunderstorm WarningEWXBandera, Edwards, Kerr, Kinney, Maverick, Medina and 4 more61 min
May 12, 7:06 AM CDTTornado WarningEWXUvalde39 min
May 12, 7:45 AM CDTTornado WarningEWXUvalde45 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, 8.3 hours before the alert went out and 47 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 2011-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2151 joules per kilogram.LCLEL10008507005003002001001 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 2011-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 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
2151 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
2314 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 7:43 PM CDTMesoscale DiscussionSPCAnderson, Bell, Blanco, Bowie, Burnet, Camp and 20 more62 min
May 11, 11:25 PM CDTMesoscale DiscussionSPCAustin, Bandera, Bastrop, Bexar, Brazos, Burleson and 27 more65 min
May 12, 2:57 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell and 25 more33 min
May 12, 7:27 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bee, Bexar, Brooks, Dimmit and 26 more33 min
May 12, 7:52 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Bandera, Bee, Bexar, Brooks and 33 more9 hr
May 12, 8:46 AM CDTMesoscale DiscussionSPCBastrop, Bell, Bosque, Brazos, Burleson, Caldwell and 22 more59 min
May 12, 9:02 AM CDTSevere Thunderstorm WatchSPCAnderson, Austin, Bastrop, Bell, Blanco, Bosque and 53 more6 hr
May 12, 11:43 AM CDTMesoscale DiscussionSPCAnderson, Aransas, Austin, Bee, Brazos, Burleson and 33 more92 min
May 12, 1:46 PM CDTMesoscale DiscussionSPCFannin, Grayson, Lamar119 min
May 12, 3:17 PM CDTSevere Thunderstorm WatchSPCCooke, Fannin, Grayson, Lamar, Montague, Red River7 hr
May 12, 6:30 PM CDTMesoscale DiscussionSPCCooke, Fannin, Grayson, Lamar90 min

Nearby

Severe Thunderstorm Watches in Texas, 2011Every severe thunderstorm watch in 2011

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.