Alert archive / Texas / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 336

May 22, 201134 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 22, 2011, 8:59 PM CDT for 34 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 22, 2011, 8:59 PM CDT (01:59 UTC)
Expired
May 22, 2011, 11:04 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 34 counties

Bell County, TX, Bosque County, TX, Collin County, TX, Comanche County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Fannin County, TX, Freestone County, TX, Grayson County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Lampasas County, TX, Limestone County, TX, McLennan County, TX, Mills County, TX, Navarro County, TX, Rains County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX, Van Zandt County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 48 km from the middle of the area, began a volume at 01:59 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
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 22, 8:59 PM CDTSevere Thunderstorm WarningFWDComanche, Erath61 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

Fort Worth, TX (KFWD), launched 00:00Z, 2.0 hours before the alert went out and 35 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, Fort Worth, TX at 00:00Z on 2011-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3311 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, Fort Worth, TX at 00:00Z on 2011-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 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
3311 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1257 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
1.6
Supercell composite
13.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 8:10 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Clay, Collin, Comanche and 34 more65 min
May 23, 9:57 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Dallas, Delta and 30 more33 min
May 23, 9:59 AM CDTSevere Thunderstorm WatchSPCBosque, Collin, Comanche, Cooke, Dallas, Delta and 29 more6 hr
May 23, 12:10 PM CDTMesoscale DiscussionSPCAnderson, Bosque, Bowie, Camp, Cass, Cherokee and 46 more65 min
May 23, 2:08 PM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Cottle, Foard, Hardeman and 11 more97 min
May 23, 2:30 PM CDTTornado WatchSPCArcher, Baylor, Clay, Foard, Hardeman, Knox and 2 more8 hr
May 23, 4:58 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Eastland, Shackelford, Stephens and 2 more62 min
May 23, 6:51 PM CDTMesoscale DiscussionSPCArcher, Clay, Wichita84 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.