Alert archive / Oklahoma / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 184

April 22, 201125 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Apr 22, 2011, 11:35 PM CDT for 25 counties in Oklahoma. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 22, 2011, 11:35 PM CDT (04:35 UTC)
Expired
Apr 23, 2011, 3:39 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 25 counties

Atoka County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 120 km from the middle of the area, began a volume at 04:36 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
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

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

IssuedProductOfficeCountiesLasted
Apr 22, 11:43 PM CDTSevere Thunderstorm WarningTSALatimer, Pittsburg, Pushmataha62 min
Apr 22, 11:49 PM CDTSevere Thunderstorm WarningOUNCleveland, Garvin, McClain, Pontotoc, Pottawatomie56 min
Apr 22, 11:49 PM CDTSevere Thunderstorm WarningTSALeFlore41 min
Apr 23, 12:13 AM CDTSevere Thunderstorm WarningOUNHughes, Pottawatomie, Seminole33 min
Apr 23, 12:29 AM CDTSevere Thunderstorm WarningOUNComanche, Grady, Stephens46 min
Apr 23, 12:32 AM CDTSevere Thunderstorm WarningOUNCoal, Hughes, Pontotoc19 min
Apr 23, 1:37 AM CDTSevere Thunderstorm WarningTSALeFlore23 min
Apr 23, 2:34 AM CDTSevere Thunderstorm WarningTSALatimer, LeFlore, Pushmataha56 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

Lamont, OK (KLMN), launched 00:00Z, 4.6 hours before the alert went out and 225 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, Lamont, OK at 00:00Z on 2011-04-23Temperature 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, Lamont, OK at 00:00Z on 2011-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 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
2322 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 8:09 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Carter, Cherokee, Coal and 25 more96 min
Apr 22, 9:39 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Carter, Choctaw, Coal and 16 more66 min
Apr 22, 11:04 PM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Craig, Delaware, Mayes, Nowata and 3 more7 hr
Apr 22, 11:10 PM CDTMesoscale DiscussionSPCAdair, Alfalfa, Blaine, Caddo, Canadian, Cherokee and 46 more2 hr
Apr 23, 2:08 AM CDTMesoscale DiscussionSPCLatimer, LeFlore, Pittsburg, Pushmataha67 min
Apr 23, 2:33 AM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Delaware, Mayes, Muskogee and 3 more87 min
Apr 23, 5:06 AM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Delaware, Mayes, Ottawa and 3 more24 min
Apr 23, 12:56 PM CDTMesoscale DiscussionSPCBryan, Carter, Choctaw, Jefferson, Johnston, Love and 2 more64 min
Apr 23, 3:05 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Cotton and 11 more9 hr
Apr 23, 5:02 PM CDTMesoscale DiscussionSPCAdair, Atoka, Choctaw, Haskell, Latimer, LeFlore and 4 more58 min

Nearby

Severe Thunderstorm Watches in Oklahoma, 2011Every 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.