Alert archive / Oklahoma / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 131

April 2, 201220 counties in Oklahoma; 8 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 2, 2012, 10:51 PM CDT for 20 counties in Oklahoma; 8 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 2, 2012, 10:51 PM CDT (03:51 UTC)
Expired
Apr 3, 2012, 4:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 28 counties

Alfalfa County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Grady County, OK, Harper County, OK, Jefferson County, OK, Kingfisher County, OK, Kiowa County, OK, Major County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Jack County, TX, Montague County, TX, Wichita County, TX, Wilbarger County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 116 km from the middle of the area, began a volume at 03:54 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
20%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 2, 10:58 PM CDTSevere Thunderstorm WarningOUNHarper, Woods, Woodward62 min
Apr 2, 11:27 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Blaine, Dewey, Major, Woods, Woodward63 min
Apr 2, 11:30 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Cotton, Grady, Stephens60 min
Apr 2, 11:52 PM CDTSevere Thunderstorm WarningOUNJackson, Tillman38 min
Apr 3, 12:49 AM CDTSevere Thunderstorm WarningOUNJackson, Tillman56 min
Apr 3, 1:39 AM CDTSevere Thunderstorm WarningOUNTillman66 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

Norman, OK (KOUN), launched 00:00Z, 3.9 hours before the alert went out and 144 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, Norman, OK at 00:00Z on 2012-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1334 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, Norman, OK at 00:00Z on 2012-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
1334 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
1408 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 2, 7:17 PM CDTMesoscale DiscussionSPCBeaver, Ellis, Harper, Roger Mills, Texas58 min
Apr 2, 9:12 PM CDTMesoscale DiscussionSPCBeaver, Beckham, Caddo, Comanche, Cotton, Custer and 13 more63 min
Apr 3, 1:14 AM CDTMesoscale DiscussionSPCCarter, Cleveland, Comanche, Cotton, Garfield, Garvin and 12 more2 hr
Apr 3, 3:32 AM CDTMesoscale DiscussionSPCCaddo, Canadian, Comanche, Cotton, Grady, Jefferson and 2 more88 min
Apr 3, 8:36 AM CDTMesoscale DiscussionSPCBryan, Carter, Jefferson, Johnston, Love, Marshall and 2 more84 min
Apr 3, 9:18 AM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Jefferson and 5 more8 hr
Apr 3, 11:47 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Jefferson, Johnston and 3 more118 min
Apr 3, 2:21 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Johnston, Love and 2 more84 min
Apr 3, 2:36 PM CDTTornado WatchSPCMcCurtain7 hr
Apr 3, 3:05 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Johnston and 5 more85 min
Apr 3, 3:43 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Choctaw, Haskell, Latimer, LeFlore and 3 more6 hr
Apr 2, 11:45 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Eastland and 17 more2 hr
Apr 3, 12:08 PM CDTTornado WatchSPCAnderson, Bell, Bosque, Collin, Coryell, Dallas and 30 more9 hr
Apr 3, 1:12 PM CDTMesoscale DiscussionSPCBosque, Collin, Dallas, Denton, Ellis, Erath and 16 more93 min
Apr 3, 1:46 PM CDTMesoscale DiscussionSPCCamp, Cass, Cherokee, Franklin, Gregg, Harrison and 9 more89 min
Apr 3, 4:38 PM CDTMesoscale DiscussionSPCAustin, Bastrop, Brazos, Burleson, Caldwell, Fayette and 10 more67 min
Apr 3, 5:00 PM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Delta, Falls and 18 more60 min
Apr 3, 6:53 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Bastrop, Bowie, Brazos, Burleson and 24 more67 min

Nearby

Severe Thunderstorm Watches in Oklahoma, 2012Severe 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.