Alert archive / Oklahoma / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 191

April 23, 201153 counties in Oklahoma; 8 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 23, 2011, 9:53 PM CDT for 53 counties in Oklahoma; 8 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Apr 23, 2011, 9:53 PM CDT (02:53 UTC)
Expired: Apr 24, 2011, 5:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 60 kt

All 61 counties

Adair County, OK, Atoka 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, Craig County, OK, Creek County, OK, Delaware County, OK, Garvin County, OK, Grady County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Kingfisher County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, Mayes County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK, Tillman County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK, Archer County, TX, Clay County, TX, Cooke County, TX, Fannin County, TX, Grayson County, TX, Lamar County, TX, Montague County, TX, Wichita County, TX

The radar

The Tulsa radar (KINX), 94 km from the middle of the area, began a volume at 02:56 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: 5%
One or more EF2 to EF5 tornadoes: 2%
Ten or more severe wind reports: 20%
One or more gusts of 65 knots or more: 10%
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

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

Issued	Product	Office	Counties	Lasted
Apr 23, 10:22 PM CDT	Severe Thunderstorm Warning	TSA	Creek, Osage, Tulsa	38 min
Apr 23, 10:26 PM CDT	Severe Thunderstorm Warning	OUN	Tillman	64 min
Apr 23, 10:36 PM CDT	Severe Thunderstorm Warning	TSA	Haskell, LeFlore, Muskogee, Sequoyah	39 min
Apr 23, 10:46 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	28 min
Apr 23, 10:50 PM CDT	Severe Thunderstorm Warning	TSA	Rogers, Tulsa	29 min
Apr 23, 10:52 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Tillman	38 min
Apr 23, 10:57 PM CDT	Severe Thunderstorm Warning	TSA	Adair, Cherokee, Delaware	63 min
Apr 23, 11:17 PM CDT	Flash Flood Warning	TSA	Adair, Cherokee, McIntosh, Muskogee, Sequoyah, Wagoner	5 hr
Apr 23, 11:19 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton	41 min
Apr 23, 11:27 PM CDT	Severe Thunderstorm Warning	OUN	Cotton	63 min
Apr 23, 11:58 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Grady, Stephens	47 min
Apr 24, 12:28 AM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	62 min
Apr 24, 1:03 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray, Stephens	57 min
Apr 24, 1:27 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Stephens	63 min
Apr 24, 1:33 AM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Noble, Oklahoma, Payne	57 min
Apr 24, 1:44 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, Stephens	61 min
Apr 24, 1:48 AM CDT	Severe Thunderstorm Warning	OUN	Comanche, Tillman	57 min
Apr 24, 1:55 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray, Pontotoc	65 min
Apr 24, 2:27 AM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Johnston, Murray, Pontotoc	78 min
Apr 24, 2:46 AM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, Stephens	44 min
Apr 24, 4:02 AM CDT	Severe Thunderstorm Warning	OUN	Coal, Hughes, Pontotoc	73 min
Apr 24, 4:44 AM CDT	Severe Thunderstorm Warning	TSA	Pittsburg	61 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, 2.9 hours before the alert went out and 109 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1103 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 244 m²/s²
0-3 km storm-relative helicity: 345 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 23, 8:09 PM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Clay, Cleburne, Conway, Craighead and 25 more	2 hr
Apr 23, 8:19 PM CDT	Tornado Watch	SPC	Baxter, Clay, Craighead, Fulton, Greene, Independence and 9 more	4 hr
Apr 23, 10:40 PM CDT	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Clay, Fulton and 8 more	95 min
Apr 24, 11:58 AM CDT	Mesoscale Discussion	SPC	Baxter, Clay, Cleburne, Conway, Craighead, Faulkner and 19 more	62 min
Apr 24, 12:27 PM CDT	Tornado Watch	SPC	Baxter, Clay, Cleburne, Conway, Craighead, Fulton and 16 more	7 hr
Apr 24, 3:31 PM CDT	Mesoscale Discussion	SPC	Cleburne, Craighead, Greene, Independence, Izard, Jackson and 9 more	59 min
Apr 24, 5:34 PM CDT	Mesoscale Discussion	SPC	Crawford, Franklin, Madison, Polk, Scott, Sebastian and 1 more	26 min
Apr 24, 5:36 PM CDT	Tornado Watch	SPC	Conway, Crawford, Franklin, Garland, Johnson, Logan and 8 more	7 hr
Apr 24, 6:23 PM CDT	Mesoscale Discussion	SPC	Baxter, Clay, Cleburne, Conway, Craighead, Faulkner and 32 more	2 hr
Apr 24, 3:01 PM CDT	Mesoscale Discussion	SPC	Mississippi, New Madrid, Scott	89 min
Apr 23, 7:04 PM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Carter, Choctaw, Coal, Jefferson and 9 more	86 min
Apr 23, 9:08 PM CDT	Mesoscale Discussion	SPC	Adair, Canadian, Cherokee, Cleveland, Craig, Creek and 26 more	97 min
Apr 24, 2:02 AM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Caddo, Canadian, Carter, Cherokee and 42 more	88 min
Apr 24, 4:17 AM CDT	Mesoscale Discussion	SPC	Blaine, Caddo, Canadian, Cherokee, Cleveland, Coal and 29 more	28 min
Apr 24, 1:13 PM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Carter, Choctaw, Coal, Cotton and 13 more	92 min
Apr 24, 2:28 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 31 more	7 hr
Apr 24, 2:19 PM CDT	Severe Thunderstorm Watch	SPC	Brown, Callahan, Coke, Coleman, Comanche, Concho and 17 more	3 hr
Apr 24, 4:51 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coke, Coleman, Comanche, Concho and 19 more	24 min
Apr 24, 4:54 PM CDT	Tornado Watch	SPC	Brown, Callahan, Coke, Coleman, Collin, Comanche and 33 more	7 hr
Apr 24, 5:22 PM CDT	Mesoscale Discussion	SPC	Crockett, Edwards, Irion, Kinney, Maverick, Menard and 4 more	83 min

Nearby

Severe Thunderstorm Watches in Oklahoma, 2011 Severe Thunderstorm Watches in Texas, 2011 Every severe thunderstorm 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.