Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 185

April 20, 201216 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 20, 2012, 2:29 PM CDT for 16 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 20, 2012, 2:29 PM CDT (19:29 UTC)
Expired
Apr 20, 2012, 7:48 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
65 kt

Counties Brooks County, TX, Cameron County, TX, Duval County, TX, Hidalgo County, TX, Jim Hogg County, TX, Jim Wells County, TX, Kenedy County, TX, Kleberg County, TX, Live Oak County, TX, McMullen County, TX, Nueces County, TX, San Patricio County, TX, Starr County, TX, Webb County, TX, Willacy County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 140 km from the middle of the area, began a volume at 19:32 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
40%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
80%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 20, 3:01 PM CDTSevere Thunderstorm WarningCRPDuval, Jim Wells, Kleberg44 min
Apr 20, 3:04 PM CDTSevere Thunderstorm WarningCRPLive Oak41 min
Apr 20, 3:09 PM CDTSevere Thunderstorm WarningBROBrooks, Jim Hogg51 min
Apr 20, 3:18 PM CDTSevere Thunderstorm WarningCRPAransas, Refugio, San Patricio42 min
Apr 20, 3:24 PM CDTSevere Thunderstorm WarningCRPJim Wells, Kleberg, Nueces, San Patricio66 min
Apr 20, 3:35 PM CDTTornado WarningCRPJim Wells, Kleberg, Nueces40 min
Apr 20, 3:42 PM CDTSevere Thunderstorm WarningCRPMcMullen48 min
Apr 20, 3:44 PM CDTSevere Thunderstorm WarningCRPDuval, Jim Wells, Kleberg61 min
Apr 20, 3:49 PM CDTSevere Thunderstorm WarningCRPBee, Live Oak41 min
Apr 20, 3:50 PM CDTSevere Thunderstorm WarningCRPAransas, Nueces, Refugio, San Patricio55 min
Apr 20, 3:57 PM CDTSevere Thunderstorm WarningBROBrooks, Jim Hogg, Starr48 min
Apr 20, 4:08 PM CDTSevere Thunderstorm WarningCRPLive Oak, McMullen37 min
Apr 20, 4:12 PM CDTTornado WarningBROJim Hogg10 min
Apr 20, 4:14 PM CDTSevere Thunderstorm WarningBROHidalgo, Starr46 min
Apr 20, 4:17 PM CDTTornado WarningCRPNueces43 min
Apr 20, 4:18 PM CDTSevere Thunderstorm WarningBROBrooks, Kenedy42 min
Apr 20, 4:37 PM CDTSevere Thunderstorm WarningBROKenedy38 min
Apr 20, 4:38 PM CDTSevere Thunderstorm WarningBROHidalgo52 min
Apr 20, 4:46 PM CDTSevere Thunderstorm WarningCRPKleberg44 min
Apr 20, 4:48 PM CDTSevere Thunderstorm WarningCRPKleberg, Nueces42 min
Apr 20, 4:58 PM CDTSevere Thunderstorm WarningBROKenedy47 min
Apr 20, 5:08 PM CDTSevere Thunderstorm WarningBROHidalgo52 min
Apr 20, 5:09 PM CDTSevere Thunderstorm WarningCRPKleberg, Nueces51 min
Apr 20, 5:16 PM CDTSevere Thunderstorm WarningBROKenedy, Willacy27 min
Apr 20, 5:27 PM CDTTornado WarningBROWillacy14 min
Apr 20, 5:30 PM CDTSevere Thunderstorm WarningBROHidalgo, Starr45 min
Apr 20, 5:40 PM CDTSevere Thunderstorm WarningBROWillacy50 min
Apr 20, 5:53 PM CDTSevere Thunderstorm WarningBROCameron, Hidalgo52 min
Apr 20, 5:56 PM CDTSevere Thunderstorm WarningBROHidalgo24 min
Apr 20, 6:11 PM CDTSevere Thunderstorm WarningBROHidalgo, Willacy29 min
Apr 20, 6:18 PM CDTSevere Thunderstorm WarningBROCameron42 min
Apr 20, 6:30 PM CDTTornado WarningBROCameron30 min
Apr 20, 6:56 PM CDTSevere Thunderstorm WarningBROCameron49 min
Apr 20, 6:57 PM CDTTornado WarningBROCameron12 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

Brownsville Intl, TX (KBRO), launched 12:00Z, 7.5 hours before the alert went out and 146 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, Brownsville Intl, TX at 12:00Z on 2012-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1336 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, Brownsville Intl, TX at 12:00Z on 2012-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
1336 J/kg
Mixed-layer CIN
-192 J/kg
Mixed-layer LCL
742 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
151 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 9:13 PM CDTMesoscale DiscussionSPCCooke, Denton, Grayson, Jack, Montague, Wise62 min
Apr 19, 10:49 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Cooke, Foard, Hardeman and 7 more116 min
Apr 20, 12:35 PM CDTMesoscale DiscussionSPCAngelina, Aransas, Austin, Bee, Brazoria, Calhoun and 33 more2 hr
Apr 20, 12:57 PM CDTSevere Thunderstorm WatchSPCAransas, Austin, Bastrop, Bee, Brazoria, Brazos and 43 more7 hr
Apr 20, 1:30 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 7 more2 hr
Apr 20, 3:44 PM CDTMesoscale DiscussionSPCAngelina, Austin, Brazoria, Brazos, Burleson, Chambers and 27 more91 min
Apr 20, 4:48 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Hidalgo, Kenedy, Kleberg, Nueces and 2 more57 min
Apr 20, 6:12 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 18 more93 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.