Alert archive / Oklahoma / Tornado Watches in 2011

Tornado Watch 870

November 7, 201123 counties in Oklahoma; 17 counties in Texas

The Storm Prediction Center issued this tornado watch at Nov 7, 2011, 1:11 PM CST for 23 counties in Oklahoma; 17 counties in Texas. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Nov 7, 2011, 1:11 PM CST (19:11 UTC)
Expired: Nov 7, 2011, 9:00 PM CST
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 60 kt

All 40 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Logan County, OK, Noble County, OK, Payne County, OK, Roger Mills County, OK, Tillman County, OK, Washita County, OK, Archer County, TX, Baylor County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Dickens County, TX, Donley County, TX, Foard County, TX, Hall County, TX, Hardeman County, TX, Kent County, TX, King County, TX, Knox County, TX, Motley County, TX, Stonewall County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 77 km from the middle of the area, began a volume at 19:12 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: 50%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 50%
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: 30%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Nov 7, 1:16 PM CST	Severe Thunderstorm Warning	OUN	Beckham, Custer, Dewey, Roger Mills	59 min
Nov 7, 1:28 PM CST	Severe Thunderstorm Warning	LUB	Childress	32 min
Nov 7, 1:46 PM CST	Severe Thunderstorm Warning	AMA	Donley, Gray	44 min
Nov 7, 1:49 PM CST	Severe Thunderstorm Warning	OUN	Greer, Harmon	56 min
Nov 7, 2:02 PM CST	Severe Thunderstorm Warning	OUN	Greer, Harmon, Jackson, Kiowa, Tillman	58 min
Nov 7, 2:14 PM CST	Tornado Warning	OUN	Greer, Harmon, Kiowa	46 min
Nov 7, 2:17 PM CST	Severe Thunderstorm Warning	OUN	Beckham, Blaine, Custer, Dewey, Roger Mills	58 min
Nov 7, 2:44 PM CST	Tornado Warning	OUN	Jackson, Kiowa, Tillman	46 min
Nov 7, 3:00 PM CST	Severe Thunderstorm Warning	OUN	Greer, Jackson, Kiowa, Washita	60 min
Nov 7, 3:08 PM CST	Tornado Warning	OUN	Kiowa, Washita	52 min
Nov 7, 3:27 PM CST	Tornado Warning	OUN	Comanche, Kiowa, Tillman	48 min
Nov 7, 3:42 PM CST	Tornado Warning	OUN	Kiowa	33 min
Nov 7, 4:05 PM CST	Severe Thunderstorm Warning	OUN	Beckham, Greer, Washita	40 min
Nov 7, 4:14 PM CST	Tornado Warning	OUN	Caddo, Comanche, Kiowa	46 min
Nov 7, 4:18 PM CST	Severe Thunderstorm Warning	OUN	Kay	42 min
Nov 7, 4:29 PM CST	Severe Thunderstorm Warning	AMA	Collingsworth, Wheeler	21 min
Nov 7, 4:33 PM CST	Severe Thunderstorm Warning	OUN	Beckham, Custer, Kiowa, Washita	42 min
Nov 7, 4:39 PM CST	Severe Thunderstorm Warning	OUN	Greer, Harmon, Jackson	51 min
Nov 7, 4:55 PM CST	Severe Thunderstorm Warning	LUB	Childress	35 min
Nov 7, 4:57 PM CST	Severe Thunderstorm Warning	OUN	Kay	63 min
Nov 7, 4:57 PM CST	Tornado Warning	OUN	Caddo	38 min
Nov 7, 5:16 PM CST	Severe Thunderstorm Warning	OUN	Custer, Kiowa, Washita	59 min
Nov 7, 5:20 PM CST	Severe Thunderstorm Warning	OUN	Beckham, Greer	40 min
Nov 7, 5:32 PM CST	Severe Thunderstorm Warning	OUN	Baylor, Wilbarger	43 min
Nov 7, 5:37 PM CST	Severe Thunderstorm Warning	OUN	Harmon, Jackson	53 min
Nov 7, 5:48 PM CST	Severe Thunderstorm Warning	OUN	Blaine, Caddo	27 min
Nov 7, 6:03 PM CST	Severe Thunderstorm Warning	LUB	Cottle, King	38 min
Nov 7, 6:12 PM CST	Severe Thunderstorm Warning	OUN	Blaine, Caddo, Canadian, Custer, Kingfisher, Kiowa and 1 more	63 min
Nov 7, 6:15 PM CST	Severe Thunderstorm Warning	OUN	Greer, Jackson	45 min
Nov 7, 6:23 PM CST	Severe Thunderstorm Warning	LUB	Dickens, Kent	37 min
Nov 7, 6:35 PM CST	Severe Thunderstorm Warning	OUN	Foard, Hardeman	55 min
Nov 7, 6:41 PM CST	Severe Thunderstorm Warning	OUN	Harmon, Jackson	49 min
Nov 7, 6:58 PM CST	Severe Thunderstorm Warning	OUN	Greer, Jackson, Kiowa	47 min
Nov 7, 7:22 PM CST	Severe Thunderstorm Warning	LUB	Cottle, King	38 min
Nov 7, 7:25 PM CST	Severe Thunderstorm Warning	OUN	Comanche, Greer, Jackson, Kiowa, Tillman, Washita	50 min
Nov 7, 8:16 PM CST	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Payne	44 min
Nov 7, 8:22 PM CST	Severe Thunderstorm Warning	OUN	Caddo, Comanche, Kiowa	53 min
Nov 7, 8:26 PM CST	Severe Thunderstorm Warning	OUN	Tillman	64 min
Nov 7, 8:44 PM CST	Severe Thunderstorm Warning	OUN	Jackson, Kiowa, Tillman	46 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, 7.2 hours before the alert went out and 191 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1081 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 482 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 163 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 4.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 6, 7:00 PM CST	Mesoscale Discussion	SPC	Carter, Garvin, Jefferson, Johnston, Love, Marshall and 2 more	90 min
Nov 7, 7:52 AM CST	Mesoscale Discussion	SPC	Alfalfa, Beckham, Blaine, Canadian, Custer, Dewey and 15 more	83 min
Nov 7, 12:27 PM CST	Mesoscale Discussion	SPC	Beckham, Caddo, Comanche, Cotton, Custer, Greer and 6 more	93 min
Nov 7, 1:30 PM CST	Mesoscale Discussion	SPC	Alfalfa, Dewey, Garfield, Grant, Kay, Kingfisher and 4 more	2 hr
Nov 7, 4:58 PM CST	Mesoscale Discussion	SPC	Nowata, Osage, Washington	92 min
Nov 7, 5:37 PM CST	Tornado Watch	SPC	Craig, Nowata, Osage, Ottawa, Pawnee, Washington	7 hr
Nov 7, 5:51 PM CST	Mesoscale Discussion	SPC	Blaine, Caddo, Canadian, Comanche, Custer, Garfield and 10 more	114 min
Nov 7, 5:53 PM CST	Mesoscale Discussion	SPC	Love, Marshall	67 min
Nov 7, 2:41 PM CST	Mesoscale Discussion	SPC	Callahan, Coke, Coleman, Eastland, Fisher, Haskell and 9 more	94 min
Nov 7, 5:04 PM CST	Mesoscale Discussion	SPC	Armstrong, Carson, Castro, Deaf Smith, Gray, Hutchinson and 3 more	56 min

Nearby

Tornado Watches in Oklahoma, 2011 Tornado Watches in Texas, 2011 Every tornado 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.