Alert archive / Texas / Tornado Watches in 2010

Tornado Watch 73

April 21, 201034 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 21, 2010, 4:09 PM CDT for 34 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 21, 2010, 4:09 PM CDT (21:09 UTC)
Expired
Apr 21, 2010, 11:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 34 counties

Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Childress County, TX, Cochran County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Deaf Smith County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hockley County, TX, Kent County, TX, King County, TX, Lamb County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Stonewall County, TX, Swisher County, TX, Terry County, TX, Wheeler County, TX, Yoakum County, TX

The radar

The Amarillo radar (KAMA), 62 km from the middle of the area, began a volume at 21:09 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
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 21, 5:15 PM CDTSevere Thunderstorm WarningLUBHale45 min
Apr 21, 5:57 PM CDTSevere Thunderstorm WarningAMAOldham63 min
Apr 21, 5:59 PM CDTSevere Thunderstorm WarningLUBFloyd, Hale46 min
Apr 21, 6:07 PM CDTSevere Thunderstorm WarningLUBFloyd, Motley23 min
Apr 21, 6:20 PM CDTTornado WarningAMAOldham25 min
Apr 21, 6:30 PM CDTSevere Thunderstorm WarningLUBFloyd, Motley45 min
Apr 21, 6:50 PM CDTSevere Thunderstorm WarningLUBDickens, Kent40 min
Apr 21, 6:55 PM CDTSevere Thunderstorm WarningAMAHartley, Oldham65 min
Apr 21, 7:14 PM CDTSevere Thunderstorm WarningLUBBriscoe, Floyd, Hall, Motley46 min
Apr 21, 7:19 PM CDTSevere Thunderstorm WarningLUBKent56 min
Apr 21, 7:40 PM CDTSevere Thunderstorm WarningLUBCottle, Dickens, King, Motley50 min
Apr 21, 7:55 PM CDTSevere Thunderstorm WarningAMAHartley, Oldham28 min
Apr 21, 8:11 PM CDTSevere Thunderstorm WarningLUBChildress, Cottle, Hall, Motley49 min
Apr 21, 8:14 PM CDTSevere Thunderstorm WarningLUBKent26 min
Apr 21, 8:27 PM CDTSevere Thunderstorm WarningLUBDickens, King36 min
Apr 21, 8:31 PM CDTSevere Thunderstorm WarningLUBHall, Motley29 min
Apr 21, 8:49 PM CDTSevere Thunderstorm WarningLUBCochran, Terry, Yoakum41 min
Apr 21, 9:01 PM CDTSevere Thunderstorm WarningLUBChildress29 min
Apr 21, 9:30 PM CDTSevere Thunderstorm WarningLUBCochran, Hockley45 min
Apr 21, 9:30 PM CDTSevere Thunderstorm WarningLUBChildress30 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 12:00Z, 9.2 hours before the alert went out and 62 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 12:00Z on 2010-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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 12:00Z on 2010-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 91 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
12 J/kg
Mixed-layer CIN
-224 J/kg
Mixed-layer LCL
1374 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
91 m²/s²
0-3 km storm-relative helicity
153 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 21, 3:22 PM CDTMesoscale DiscussionSPCArmstrong, Briscoe, Castro, Childress, Cottle, Dallam and 12 more83 min
Apr 21, 3:49 PM CDTSevere Thunderstorm WatchSPCDallam, Hartley6 hr
Apr 21, 6:29 PM CDTMesoscale DiscussionSPCDallam, Hartley91 min

Nearby

Tornado Watches in Texas, 2010Every tornado watch in 2010

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.