Alert archive / Oklahoma / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 134

April 13, 200750 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Apr 13, 2007, 1:59 PM CDT for 50 counties in Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 13, 2007, 1:59 PM CDT (18:59 UTC)
Expired
Apr 13, 2007, 8:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 50 counties

Adair County, OK, Atoka County, OK, Blaine County, OK, Bryan County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Creek County, OK, Custer County, OK, Garvin County, OK, Grady County, OK, Haskell County, OK, Hughes County, OK, Jackson County, OK, Jefferson County, OK, Johnston County, OK, Kingfisher County, OK, Kiowa County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, McClain County, OK, McCurtain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK, Tillman County, OK, Tulsa County, OK, Wagoner County, OK, Washita County, OK

The radar

The Norman radar (KTLX), 14 km from the middle of the area, began a volume at 18:59 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
30%
One or more gusts of 65 knots or more
30%
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

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

IssuedProductOfficeCountiesLasted
Apr 13, 2:42 PM CDTSevere Thunderstorm WarningTSATulsa, Wagoner31 min
Apr 13, 4:30 PM CDTSevere Thunderstorm WarningOUNJefferson45 min
Apr 13, 5:15 PM CDTSevere Thunderstorm WarningOUNStephens45 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 12:00Z, 7.0 hours before the alert went out and 7 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 12:00Z on 2007-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2007-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 669 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1239 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
669 m²/s²
0-3 km storm-relative helicity
913 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 7:37 PM CDTMesoscale DiscussionSPCBeckham, Comanche, Cotton, Greer, Harmon, Jackson and 4 more113 min
Apr 12, 11:46 PM CDTSevere Thunderstorm WatchSPCGreer, Harmon, Jackson7 hr
Apr 13, 2:36 AM CDTMesoscale DiscussionSPCBeckham, Ellis, Greer, Harmon, Jackson, Kiowa and 1 more84 min
Apr 13, 5:34 AM CDTMesoscale DiscussionSPCBeaver, Beckham, Blaine, Caddo, Comanche, Custer and 13 more86 min
Apr 13, 12:37 PM CDTMesoscale DiscussionSPCAtoka, Caddo, Canadian, Carter, Choctaw, Cleveland and 30 more113 min
Apr 13, 2:51 PM CDTMesoscale DiscussionSPCLove54 min
Apr 12, 9:35 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Childress and 35 more115 min
Apr 12, 11:31 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Carson and 38 more119 min
Apr 13, 12:12 PM CDTMesoscale DiscussionSPCArcher, Baylor, Fisher, Haskell, Hood, Jack and 8 more63 min
Apr 13, 12:27 PM CDTTornado WatchSPCArcher, Baylor, Brown, Callahan, Clay, Coke and 27 more7 hr
Apr 13, 5:08 PM CDTMesoscale DiscussionSPCAngelina, Chambers, Cherokee, Hardin, Harris, Harrison and 18 more97 min
Apr 13, 5:43 PM CDTTornado Watch PDSSPCBell, Bosque, Collin, Cooke, Coryell, Dallas and 22 more4 hr
Apr 13, 5:48 PM CDTTornado Watch PDSSPCAnderson, Angelina, Bowie, Brazos, Burleson, Camp and 39 more8 hr
Apr 13, 5:58 PM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Edwards, Gillespie, Hays and 16 more62 min
Apr 13, 6:27 PM CDTTornado WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 26 more8 hr

Nearby

Severe Thunderstorm Watches in Oklahoma, 2007Every severe thunderstorm watch in 2007

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.