Alert archive / Oklahoma / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 525

June 20, 201132 counties in Oklahoma; 17 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Jun 20, 2011, 3:42 PM CDT for 32 counties in Oklahoma; 17 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 20, 2011, 3:42 PM CDT (20:42 UTC)
Expired: Jun 20, 2011, 11:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Particularly dangerous situation: Yes
Largest hail expected: 3.5 in
Strongest gust expected: 70 kt

All 49 counties

Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Creek County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Jefferson County, OK, Johnston County, OK, Kay County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Okfuskee County, OK, Oklahoma County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Tulsa County, OK, Washington County, OK, Archer County, TX, Callahan County, TX, Clay County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Jack County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The Norman radar (KTLX), 59 km from the middle of the area, began a volume at 20:58 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: 90%
One or more gusts of 65 knots or more: 80%
Ten or more severe hail reports: 90%
One or more hailstones of 2 inches or more: 70%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 20, 4:37 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	35 min
Jun 20, 5:02 PM CDT	Severe Thunderstorm Warning	SJT	Throckmorton	28 min
Jun 20, 5:06 PM CDT	Severe Thunderstorm Warning	SJT	Throckmorton	39 min
Jun 20, 5:24 PM CDT	Severe Thunderstorm Warning	FWD	Young	66 min
Jun 20, 5:34 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Baylor, Clay	56 min
Jun 20, 5:45 PM CDT	Severe Thunderstorm Warning	SJT	Throckmorton	15 min
Jun 20, 5:46 PM CDT	Severe Thunderstorm Warning	OUN	Grant, Kay	59 min
Jun 20, 5:50 PM CDT	Severe Thunderstorm Warning	SJT	Throckmorton	40 min
Jun 20, 5:59 PM CDT	Severe Thunderstorm Warning	SJT	Throckmorton	46 min
Jun 20, 6:02 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	58 min
Jun 20, 6:09 PM CDT	Severe Thunderstorm Warning	FWD	Young	66 min
Jun 20, 6:09 PM CDT	Tornado Warning	SJT	Throckmorton	36 min
Jun 20, 6:29 PM CDT	Severe Thunderstorm Warning	FWD	Jack, Young	46 min
Jun 20, 6:35 PM CDT	Severe Thunderstorm Warning	OUN	Garfield, Grant, Kay, Noble	55 min
Jun 20, 6:43 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, McClain, Stephens	25 min
Jun 20, 6:47 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	58 min
Jun 20, 6:58 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Jefferson, Stephens	47 min
Jun 20, 7:03 PM CDT	Severe Thunderstorm Warning	FWD	Jack, Young	57 min
Jun 20, 7:15 PM CDT	Severe Thunderstorm Warning	FWD	Jack	45 min
Jun 20, 7:30 PM CDT	Severe Thunderstorm Warning	OUN	Garfield, Kay, Noble	60 min
Jun 20, 7:38 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Murray	67 min
Jun 20, 7:40 PM CDT	Severe Thunderstorm Warning	FWD	Stephens, Young	65 min
Jun 20, 7:42 PM CDT	Severe Thunderstorm Warning	FWD	Montague, Wise	39 min
Jun 20, 7:43 PM CDT	Severe Thunderstorm Warning	OUN	Clay	17 min
Jun 20, 7:57 PM CDT	Severe Thunderstorm Warning	FWD	Jack, Wise	63 min
Jun 20, 8:09 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Pawnee	96 min
Jun 20, 8:10 PM CDT	Severe Thunderstorm Warning	OUN	Kingfisher, Logan, Payne	65 min
Jun 20, 8:30 PM CDT	Severe Thunderstorm Warning	FWD	Jack	60 min
Jun 20, 8:35 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Logan, Oklahoma	55 min
Jun 20, 8:38 PM CDT	Severe Thunderstorm Warning	FWD	Jack, Palo Pinto, Stephens, Young	52 min
Jun 20, 8:40 PM CDT	Severe Thunderstorm Warning	OUN	Kay, Noble, Payne	65 min
Jun 20, 8:45 PM CDT	Tornado Warning	FWD	Palo Pinto, Young	30 min
Jun 20, 8:51 PM CDT	Severe Thunderstorm Warning	TSA	Osage	54 min
Jun 20, 8:56 PM CDT	Severe Thunderstorm Warning	FWD	Wise	49 min
Jun 20, 9:15 PM CDT	Tornado Warning	FWD	Palo Pinto	30 min
Jun 20, 9:17 PM CDT	Severe Thunderstorm Warning	FWD	Cooke, Denton	58 min
Jun 20, 9:20 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Pawnee	55 min
Jun 20, 9:25 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Noble, Oklahoma, Payne	65 min
Jun 20, 9:28 PM CDT	Severe Thunderstorm Warning	FWD	Jack, Palo Pinto, Parker, Wise, Young	62 min
Jun 20, 9:43 PM CDT	Severe Thunderstorm Warning	FWD	Denton, Wise	62 min
Jun 20, 9:51 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Tulsa, Washington	54 min
Jun 20, 10:09 PM CDT	Severe Thunderstorm Warning	TSA	Creek, Osage, Pawnee, Tulsa	81 min
Jun 20, 10:28 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Oklahoma, Payne	47 min
Jun 20, 10:29 PM CDT	Severe Thunderstorm Warning	FWD	Parker, Wise	61 min
Jun 20, 10:31 PM CDT	Severe Thunderstorm Warning	FWD	Denton	59 min
Jun 20, 10:49 PM CDT	Severe Thunderstorm Warning	TSA	Creek, Osage, Rogers, Tulsa, Wagoner	71 min
Jun 20, 10:56 PM CDT	Severe Thunderstorm Warning	OUN	Clay	34 min
Jun 20, 11:00 PM CDT	Severe Thunderstorm Warning	FWD	Denton, Tarrant	60 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, 8.7 hours before the alert went out and 44 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: 1692 J/kg
Mixed-layer CIN: -552 J/kg
Mixed-layer LCL: 1064 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 367 m²/s²
0-3 km storm-relative helicity: 400 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 10:42 AM CDT	Mesoscale Discussion	SPC	Cleveland, Creek, Kay, Lincoln, Logan, McClain and 13 more	63 min
Jun 20, 1:34 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Canadian, Garfield, Grant, Kay, Kingfisher and 7 more	116 min
Jun 20, 3:21 PM CDT	Mesoscale Discussion	SPC	Canadian, Carter, Cleveland, Coal, Comanche, Cotton and 27 more	84 min
Jun 20, 5:35 PM CDT	Mesoscale Discussion	SPC	Caddo, Canadian, Carter, Cleveland, Comanche, Cotton and 19 more	85 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.