Alert archive / Oklahoma / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 504
The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2011, 3:54 PM CDT for 16 counties in Oklahoma; 16 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 18, 2011, 3:54 PM CDT (20:54 UTC)
- Expired
- Jun 18, 2011, 11:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 32 counties
Bryan County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Archer County, TX, Callahan County, TX, Clay County, TX, Cooke County, TX, Eastland County, TX, Jack County, TX, Jones County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Wise County, TX, Young County, TX
The radar
The Altus AFB radar (KFDR), 120 km from the middle of the area, began a volume at 20:53 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
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 4:23 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Murray | 52 min |
| Jun 18, 5:14 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Johnston, Murray | 61 min |
| Jun 18, 5:21 PM CDT | Severe Thunderstorm Warning | SJT | Nolan, Taylor | 54 min |
| Jun 18, 5:43 PM CDT | Severe Thunderstorm Warning | FWD | Palo Pinto | 62 min |
| Jun 18, 5:47 PM CDT | Severe Thunderstorm Warning | FWD | Cooke | 58 min |
| Jun 18, 5:57 PM CDT | Severe Thunderstorm Warning | OUN | Love, Marshall | 48 min |
| Jun 18, 6:25 PM CDT | Severe Thunderstorm Warning | FWD | Jack, Wise | 50 min |
| Jun 18, 6:46 PM CDT | Severe Thunderstorm Warning | OUN | Love, Marshall | 59 min |
| Jun 18, 6:58 PM CDT | Severe Thunderstorm Warning | FWD | Cooke, Montague | 62 min |
| Jun 18, 7:08 PM CDT | Severe Thunderstorm Warning | FWD | Cooke, Denton, Montague, Wise | 27 min |
| Jun 18, 7:56 PM CDT | Severe Thunderstorm Warning | FWD | Cooke | 34 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, 8.9 hours before the alert went out and 118 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.
- Mixed-layer CAPE
- 2233 J/kg
- Mixed-layer CIN
- -458 J/kg
- Mixed-layer LCL
- 1688 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 467 m²/s²
- 0-3 km storm-relative helicity
- 489 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 3:24 PM CDT | Mesoscale Discussion | SPC | Jefferson, Stephens | 66 min |
| Jun 18, 3:34 PM CDT | Mesoscale Discussion | SPC | Craig, Nowata, Osage, Ottawa, Washington | 116 min |
| Jun 18, 6:03 PM CDT | Severe Thunderstorm Watch | SPC | Craig, Grant, Kay, Nowata, Osage, Ottawa and 1 more | 10 hr |
Nearby
Severe Thunderstorm Watches in Oklahoma, 2011Severe Thunderstorm Watches in Texas, 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.