Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 206

April 29, 201212 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 29, 2012, 8:55 PM CDT for 12 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 29, 2012, 8:55 PM CDT (01:55 UTC)
Expired
Apr 30, 2012, 3:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt

Counties Armstrong County, TX, Carson County, TX, Collingsworth County, TX, Donley County, TX, Gray County, TX, Hemphill County, TX, Hutchinson County, TX, Moore County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 33 km from the middle of the area, began a volume at 01:57 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
10%
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
40%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 29, 9:25 PM CDTSevere Thunderstorm WarningAMAHansford, Hutchinson, Lipscomb, Ochiltree, Roberts65 min
Apr 29, 9:30 PM CDTSevere Thunderstorm WarningAMAArmstrong, Donley, Randall47 min
Apr 29, 9:53 PM CDTSevere Thunderstorm WarningAMAHutchinson, Moore, Roberts52 min
Apr 29, 10:30 PM CDTSevere Thunderstorm WarningAMAHemphill, Lipscomb, Ochiltree, Roberts60 min
Apr 29, 10:34 PM CDTSevere Thunderstorm WarningAMADallam, Hartley, Moore, Sherman56 min
Apr 29, 11:20 PM CDTSevere Thunderstorm WarningAMAHartley, Hutchinson, Moore55 min
Apr 29, 11:26 PM CDTSevere Thunderstorm WarningAMAGray, Hemphill, Roberts, Wheeler64 min
Apr 29, 11:54 PM CDTSevere Thunderstorm WarningAMAArmstrong, Donley, Randall54 min
Apr 30, 12:15 AM CDTSevere Thunderstorm WarningAMACarson, Gray, Hutchinson, Moore, Roberts60 min
Apr 30, 1:14 AM CDTSevere Thunderstorm WarningAMACarson, Gray, Hemphill, Roberts, Wheeler45 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 1.9 hours before the alert went out and 32 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, Amarillo Airport, TX at 00:00Z on 2012-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 63 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, Amarillo Airport, TX at 00:00Z on 2012-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.1939587897Sfc1 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
63 J/kg
Mixed-layer CIN
-116 J/kg
Mixed-layer LCL
2070 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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, 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
Apr 30, 6:54 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Callahan, Coke, Coleman, Concho and 33 more6 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.