Alert archive / Oklahoma / Tornado Watches in 2015

Tornado Watch 64

April 16, 20155 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at Apr 16, 2015, 6:09 PM CDT for 5 counties in Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 16, 2015, 6:09 PM CDT (23:09 UTC)
Expired
Apr 16, 2015, 11:59 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Beckham County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Roger Mills County, OK

The radar

The Altus AFB radar (KFDR), 174 km from the middle of the area, began a volume at 23:10 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
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 16, 6:25 PM CDTSevere Thunderstorm WarningOUNBeckham, Greer, Roger Mills50 min
Apr 16, 6:31 PM CDTSevere Thunderstorm WarningOUNGreer, Harmon44 min
Apr 16, 6:42 PM CDTSevere Thunderstorm WarningOUNEllis, Roger Mills63 min
Apr 16, 6:48 PM CDTTornado WarningOUNRoger Mills42 min
Apr 16, 7:32 PM CDTSevere Thunderstorm WarningOUNBeckham, Greer43 min
Apr 16, 7:42 PM CDTSevere Thunderstorm WarningOUNBeckham, Custer, Ellis, Roger Mills, Woodward63 min
Apr 16, 8:01 PM CDTTornado WarningOUNBeckham29 min
Apr 16, 8:35 PM CDTTornado WarningOUNRoger Mills40 min
Apr 16, 9:11 PM CDTTornado WarningOUNBeckham, Roger Mills49 min
Apr 16, 9:57 PM CDTSevere Thunderstorm WarningOUNBeckham, Custer, Dewey, Ellis, Roger Mills48 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 12:00Z, 11.2 hours before the alert went out and 176 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, Amarillo Airport, TX at 12:00Z on 2015-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 246 joules per kilogram.LCLLFCEL10008507005003002001001 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, Amarillo Airport, TX at 12:00Z on 2015-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 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
246 J/kg
Mixed-layer CIN
-181 J/kg
Mixed-layer LCL
2122 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 12:17 PM CDTMesoscale DiscussionSPCBeaver, Harper118 min
Apr 16, 1:48 PM CDTTornado WatchSPCBeaver, Texas8 hr
Apr 16, 2:42 PM CDTMesoscale DiscussionSPCLove63 min
Apr 16, 4:06 PM CDTMesoscale DiscussionSPCJackson2 hr
Apr 16, 4:40 PM CDTSevere Thunderstorm WatchSPCComanche, Cotton, Greer, Harmon, Jackson, Kiowa and 1 more7 hr
Apr 16, 4:44 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Custer, Dewey, Ellis, Greer and 7 more3 hr
Apr 16, 4:59 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Custer, Dewey and 9 more7 hr
Apr 16, 5:06 PM CDTMesoscale DiscussionSPCBeaver, Texas84 min
Apr 16, 5:29 PM CDTMesoscale DiscussionSPCCimarron91 min
Apr 16, 5:41 PM CDTMesoscale DiscussionSPCBeckham, Roger Mills94 min

Nearby

Tornado Watches in Oklahoma, 2015Every tornado 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.