Alert archive / Oklahoma / Tornado Watches in 2009

Tornado Watch 759

October 8, 200928 counties in Oklahoma; 24 counties in Texas

The Storm Prediction Center issued this tornado watch at Oct 8, 2009, 4:41 PM CDT for 28 counties in Oklahoma; 24 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Oct 8, 2009, 4:41 PM CDT (21:41 UTC)
Expired: Oct 9, 2009, 12:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 60 kt

All 52 counties

Adair County, OK, Atoka County, OK, Bryan County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Cotton County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Okfuskee County, OK, Okmulgee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK, Archer County, TX, Baylor County, TX, Callahan County, TX, Clay County, TX, Cooke County, TX, Denton County, TX, Fisher County, TX, Grayson County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Stonewall County, TX, Taylor County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 92 km from the middle of the area, began a volume at 21:44 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: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 60%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Oct 8, 4:49 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain, Pottawatomie, Seminole	41 min
Oct 8, 5:24 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray, Stephens	25 min
Oct 8, 5:30 PM CDT	Severe Thunderstorm Warning	OUN	Wichita	45 min
Oct 8, 6:19 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Knox	56 min
Oct 8, 6:39 PM CDT	Flash Flood Warning	TSA	Adair, Cherokee, McIntosh, Muskogee, Okfuskee, Okmulgee	6 hr
Oct 8, 6:43 PM CDT	Severe Thunderstorm Warning	OUN	Baylor, Wilbarger	48 min
Oct 8, 6:50 PM CDT	Tornado Warning	SJT	Coke, Nolan, Sterling	40 min
Oct 8, 6:58 PM CDT	Severe Thunderstorm Warning	TSA	Adair, Cherokee, Delaware	62 min
Oct 8, 7:22 PM CDT	Tornado Warning	SJT	Nolan, Taylor	38 min
Oct 8, 7:36 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Tillman	39 min
Oct 8, 7:45 PM CDT	Severe Thunderstorm Warning	SJT	Coke, Nolan, Sterling	30 min
Oct 8, 8:18 PM CDT	Severe Thunderstorm Warning	SJT	Jones, Nolan, Taylor	42 min
Oct 8, 8:50 PM CDT	Severe Thunderstorm Warning	SJT	Callahan, Jones, Shackelford, Taylor	40 min
Oct 8, 8:56 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Hughes, Pontotoc	49 min
Oct 8, 9:08 PM CDT	Flash Flood Warning	TSA	Haskell, Latimer, LeFlore, Pittsburg, Sequoyah	13 hr
Oct 8, 9:40 PM CDT	Severe Thunderstorm Warning	TSA	Haskell, LeFlore, Sequoyah	50 min
Oct 8, 10:28 PM CDT	Severe Thunderstorm Warning	SJT	Fisher, Jones, Nolan, Taylor	47 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, 9.7 hours before the alert went out and 152 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: 245 J/kg
Mixed-layer CIN: -315 J/kg
Mixed-layer LCL: 421 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 335 m²/s²
0-3 km storm-relative helicity: 349 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 8, 2:51 AM CDT	Mesoscale Discussion	SPC	Alfalfa, Beaver, Dewey, Ellis, Garfield, Grant and 7 more	3 hr
Oct 8, 10:48 AM CDT	Mesoscale Discussion	SPC	Craig, Kay, Mayes, Noble, Nowata, Osage and 5 more	3 hr
Oct 8, 2:42 PM CDT	Mesoscale Discussion	SPC	Caddo, Canadian, Carter, Cherokee, Cleveland, Comanche and 24 more	63 min
Oct 8, 3:02 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Atoka, Bryan, Caddo, Canadian, Carter and 35 more	6 hr
Oct 8, 6:59 PM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Carter, Cherokee, Cleveland, Coal and 23 more	61 min
Oct 7, 11:05 PM CDT	Mesoscale Discussion	SPC	Andrews, Bailey, Borden, Briscoe, Castro, Cochran and 25 more	85 min
Oct 8, 4:25 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Brown, Callahan, Clay, Coke and 42 more	65 min
Oct 8, 4:56 PM CDT	Severe Thunderstorm Watch	SPC	Brown, Coke, Coleman, Concho, Crockett, Edwards and 18 more	9 hr

Nearby

Tornado Watches in Oklahoma, 2009 Tornado Watches in Texas, 2009 Every tornado watch in 2009

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.