Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 213

April 30, 201239 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 30, 2012, 6:54 PM CDT for 39 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 30, 2012, 6:54 PM CDT (23:54 UTC)
Expired
May 1, 2012, 12:54 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
65 kt
All 39 counties

Archer County, TX, Baylor County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Concho County, TX, Crockett County, TX, Eastland County, TX, Edwards County, TX, Fisher County, TX, Foard County, TX, Glasscock County, TX, Haskell County, TX, Irion County, TX, Jones County, TX, Kimble County, TX, Kinney County, TX, Knox County, TX, Maverick County, TX, Menard County, TX, Mitchell County, TX, Nolan County, TX, Reagan County, TX, Real County, TX, Runnels County, TX, Schleicher County, TX, Scurry County, TX, Shackelford County, TX, Stephens County, TX, Sterling County, TX, Sutton County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Uvalde County, TX, Val Verde County, TX, Wichita County, TX, Wilbarger County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 89 km from the middle of the area, began a volume at 23:57 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
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
80%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 30, 7:43 PM CDTSevere Thunderstorm WarningMAFBorden, Scurry62 min
Apr 30, 10:15 PM CDTSevere Thunderstorm WarningOUNHardeman, Wilbarger60 min
Apr 30, 11:11 PM CDTSevere Thunderstorm WarningOUNHardeman, Wilbarger53 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, 11.9 hours before the alert went out and 197 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 2012-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1590 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 2012-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 square meters per square second.1939Sfc1 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
1590 J/kg
Mixed-layer CIN
-246 J/kg
Mixed-layer LCL
1149 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 7:23 PM CDTSevere Thunderstorm WatchSPCAndrews, Bailey, Borden, Briscoe, Castro, Cochran and 14 more4 hr
Apr 29, 7:33 PM CDTMesoscale DiscussionSPCCarson, Dallam, Gray, Hansford, Hartley, Hemphill and 8 more87 min
Apr 29, 8:55 PM CDTSevere Thunderstorm WatchSPCArmstrong, Carson, Collingsworth, Donley, Gray, Hemphill and 6 more6 hr
Apr 29, 10:04 PM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Castro, Childress and 29 more86 min
Apr 29, 10:31 PM CDTMesoscale DiscussionSPCDallam, Hansford, Lipscomb, Ochiltree, Sherman119 min
Apr 29, 10:50 PM CDTSevere Thunderstorm WatchSPCBailey, Borden, Castro, Cochran, Dawson, Garza and 11 more4 hr
Apr 30, 12:38 AM CDTMesoscale DiscussionSPCArmstrong, Carson, Collingsworth, Donley, Gray, Hansford and 9 more37 min
Apr 30, 2:15 AM CDTMesoscale DiscussionSPCBriscoe, Castro, Crosby, Dickens, Floyd, Garza and 5 more30 min
Apr 30, 2:08 PM CDTMesoscale DiscussionSPCCrane, Ector, Midland, Pecos, Terrell, Upton97 min
Apr 30, 2:39 PM CDTSevere Thunderstorm WatchSPCBorden, Brewster, Crane, Dawson, Ector, Howard and 12 more7 hr
Apr 30, 2:58 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Cochran and 21 more62 min
Apr 30, 3:36 PM CDTSevere Thunderstorm WatchSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 35 more7 hr
Apr 30, 5:19 PM CDTMesoscale DiscussionSPCGray, Hemphill, Lipscomb, Ochiltree, Roberts, Wheeler56 min
Apr 30, 5:42 PM CDTTornado WatchSPCArmstrong, Briscoe, Carson, Childress, Collingsworth, Donley and 12 more7 hr
Apr 30, 6:11 PM CDTMesoscale DiscussionSPCBaylor, Borden, Callahan, Coke, Coleman, Concho and 48 more2 hr

Nearby

Severe Thunderstorm Watches in Texas, 2012Every severe thunderstorm watch in 2012

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.