Alert archive / Oklahoma / Severe Thunderstorm Watches in 2015
Severe Thunderstorm Watch 66
The Storm Prediction Center issued this severe thunderstorm watch at Apr 16, 2015, 11:59 PM CDT for 10 counties in Oklahoma; 6 counties in Texas. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 16, 2015, 11:59 PM CDT (04:59 UTC)
- Expired
- Apr 17, 2015, 5:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Kiowa County, OK, Roger Mills County, OK, Washita County, OK, Collingsworth County, TX, Donley County, TX, Gray County, TX, Hemphill County, TX, Roberts County, TX, Wheeler County, TX
The radar
The Altus AFB radar (KFDR), 158 km from the middle of the area, began a volume at 04:59 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
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 17, 12:51 AM CDT | Severe Thunderstorm Warning | AMA | Collingsworth, Donley, Gray, Hemphill, Wheeler | 54 min |
| Apr 17, 1:25 AM CDT | Severe Thunderstorm Warning | OUN | Ellis, Roger Mills | 50 min |
| Apr 17, 3:02 AM CDT | Severe Thunderstorm Warning | OUN | Beckham, Greer, Harmon, Jackson | 43 min |
| Apr 17, 3:33 AM CDT | Severe Thunderstorm Warning | OUN | Beckham, Custer, Greer, Harmon, Kiowa, Roger Mills and 1 more | 42 min |
| Apr 17, 4:13 AM CDT | Severe Thunderstorm Warning | OUN | Beckham, Custer, Dewey, Greer, Kiowa, Roger Mills and 1 more | 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
Amarillo Airport, TX (KAMA), launched 00:00Z, 5.0 hours before the alert went out and 186 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
- 301 J/kg
- Mixed-layer CIN
- -116 J/kg
- Mixed-layer LCL
- 1659 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 17 m²/s²
- 0-3 km storm-relative helicity
- 142 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 16, 7:08 PM CDT | Mesoscale Discussion | SPC | Beckham, Ellis, Roger Mills | 2 hr |
| Apr 16, 7:16 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Caddo, Comanche, Cotton, Custer and 10 more | 89 min |
| Apr 16, 7:44 PM CDT | Mesoscale Discussion | SPC | Cimarron, Texas | 61 min |
| Apr 16, 8:56 PM CDT | Mesoscale Discussion | SPC | Roger Mills | 94 min |
| Apr 16, 9:17 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Caddo, Custer, Dewey, Garfield and 5 more | 88 min |
| Apr 16, 10:20 PM CDT | Mesoscale Discussion | SPC | Beckham, Ellis, Harmon, Roger Mills | 2 hr |
| Apr 17, 2:02 AM CDT | Mesoscale Discussion | SPC | Beckham, Blaine, Custer, Dewey, Ellis, Greer and 6 more | 88 min |
| Apr 17, 4:43 AM CDT | Mesoscale Discussion | SPC | Beckham, Blaine, Caddo, Canadian, Comanche, Custer and 8 more | 62 min |
| Apr 17, 3:06 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Beaver, Beckham, Blaine, Custer, Dewey and 12 more | 84 min |
| Apr 16, 8:20 PM CDT | Mesoscale Discussion | SPC | Brazoria, Chambers, Colorado, Fort Bend, Galveston, Harris and 2 more | 85 min |
| Apr 16, 8:36 PM CDT | Tornado Watch | SPC | Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 10 more | 3 hr |
| Apr 16, 11:33 PM CDT | Mesoscale Discussion | SPC | Austin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 6 more | 87 min |
| Apr 17, 1:10 AM CDT | Mesoscale Discussion | SPC | Borden, Childress, Cottle, Crosby, Dawson, Dickens and 13 more | 95 min |
| Apr 17, 10:26 AM CDT | Mesoscale Discussion | SPC | Bandera, Bexar, Blanco, Burnet, Comal, Edwards and 12 more | 2 hr |
| Apr 17, 10:55 AM CDT | Mesoscale Discussion | SPC | Baylor, Brown, Callahan, Coke, Coleman, Concho and 15 more | 2 hr |
| Apr 17, 11:53 AM CDT | Severe Thunderstorm Watch | SPC | Archer, Atascosa, Bandera, Baylor, Bee, Bell and 73 more | 7 hr |
| Apr 17, 1:31 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bee, Calhoun, DeWitt, Dimmit, Frio and 12 more | 89 min |
| Apr 17, 3:22 PM CDT | Mesoscale Discussion | SPC | Aransas, Bee, Brazoria, Calhoun, Colorado, DeWitt and 11 more | 113 min |
| Apr 17, 3:30 PM CDT | Severe Thunderstorm Watch | SPC | Aransas, Atascosa, Austin, Bastrop, Brazoria, Brazos and 30 more | 6 hr |
| Apr 17, 5:02 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Bosque, Brown, Callahan, Clay and 28 more | 88 min |
| Apr 17, 5:41 PM CDT | Mesoscale Discussion | SPC | Aransas, Atascosa, Bee, Brazoria, Brooks, Calhoun and 26 more | 94 min |
| Apr 17, 6:57 PM CDT | Tornado Watch | SPC | Aransas, Bee, Brooks, Calhoun, Duval, Goliad and 16 more | 5 hr |
Nearby
Severe Thunderstorm Watches in Oklahoma, 2015Severe Thunderstorm Watches in Texas, 2015Every severe thunderstorm watch in 2015
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.