Alert archive / Texas / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 863

October 7, 201123 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Oct 7, 2011, 11:57 PM CDT for 23 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Oct 7, 2011, 11:57 PM CDT (04:57 UTC)
Expired
Oct 8, 2011, 6:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 23 counties

Andrews County, TX, Bailey County, TX, Castro County, TX, Cochran County, TX, Crane County, TX, Dawson County, TX, Ector County, TX, Gaines County, TX, Hale County, TX, Hockley County, TX, Lamb County, TX, Loving County, TX, Lubbock County, TX, Lynn County, TX, Martin County, TX, Midland County, TX, Parmer County, TX, Swisher County, TX, Terry County, TX, Upton County, TX, Ward County, TX, Winkler County, TX, Yoakum County, TX

The radar

The Lubbock radar (KLBB), 88 km from the middle of the area, began a volume at 04:59 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
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 8, 12:19 AM CDTSevere Thunderstorm WarningMAFDawson, Martin26 min
Oct 8, 4:39 AM CDTFlash Flood WarningMAFMidland2 hr

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 00:00Z, 5.0 hours before the alert went out and 169 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 00:00Z on 2011-10-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 493 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 00:00Z on 2011-10-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
493 J/kg
Mixed-layer CIN
-177 J/kg
Mixed-layer LCL
2174 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
74 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
Oct 7, 8:40 PM CDTMesoscale DiscussionSPCBailey, Castro, Cochran, Gaines, Hockley, Lamb and 3 more95 min
Oct 7, 10:25 PM CDTMesoscale DiscussionSPCDallam, Hartley, Moore, Oldham, Sherman95 min
Oct 7, 11:39 PM CDTMesoscale DiscussionSPCAndrews, Bailey, Borden, Castro, Cochran, Crane and 21 more96 min
Oct 8, 12:55 AM CDTMesoscale DiscussionSPCDallam, Hansford, Hartley, Moore, Oldham, Potter and 1 more95 min
Oct 8, 1:47 AM CDTSevere Thunderstorm WatchSPCArmstrong, Carson, Dallam, Deaf Smith, Donley, Gray and 11 more5 hr
Oct 8, 5:28 AM CDTMesoscale DiscussionSPCArmstrong, Carson, Donley, Gray, Hale, Hansford and 7 more62 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.