Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 250

May 5, 201217 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 5, 2012, 5:02 PM CDT for 17 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 5, 2012, 5:02 PM CDT (22:02 UTC)
Expired
May 5, 2012, 10:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Blanco County, TX, Brown County, TX, Burnet County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Coryell County, TX, Gillespie County, TX, Hamilton County, TX, Kimble County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, San Saba County, TX

The radar

The San Angelo radar (KSJT), 140 km from the middle of the area, began a volume at 22:04 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
5%
One or more EF2 to EF5 tornadoes
2%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 5, 6:37 PM CDTSevere Thunderstorm WarningSJTMcCulloch, Mason, Menard38 min
May 5, 7:05 PM CDTSevere Thunderstorm WarningSJTBrown40 min
May 5, 7:38 PM CDTSevere Thunderstorm WarningSJTBrown37 min
May 5, 7:48 PM CDTSevere Thunderstorm WarningFWDComanche, Mills57 min
May 5, 7:52 PM CDTSevere Thunderstorm WarningSJTMenard38 min
May 5, 8:11 PM CDTSevere Thunderstorm WarningSJTBrown25 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

Del Rio, TX (KDRT), launched 12:00Z, 10.0 hours before the alert went out and 246 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, Del Rio, TX at 12:00Z on 2012-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3287 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, Del Rio, TX at 12:00Z on 2012-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 213 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
3287 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
326 m²/s²
Significant tornado parameter
0.0
Supercell composite
12.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 4, 7:28 PM CDTMesoscale DiscussionSPCArcher, Bosque, Brown, Callahan, Clay, Coleman and 21 more62 min
May 4, 9:53 PM CDTMesoscale DiscussionSPCBosque, Collin, Dallas, Ellis, Grayson, Hamilton and 6 more67 min
May 5, 4:44 PM CDTMesoscale DiscussionSPCBosque, Brown, Burnet, Callahan, Coleman, Comanche and 21 more61 min
May 5, 6:09 PM CDTMesoscale DiscussionSPCAtascosa, La Salle, Live Oak, McMullen66 min

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.