Alert archive / Oklahoma / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 286

May 27, 201715 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at May 27, 2017, 9:39 PM CDT for 15 counties in Oklahoma. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 27, 2017, 9:39 PM CDT (02:39 UTC)
Expired
May 28, 2017, 1:40 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt

Counties Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Harper County, OK, Kingfisher County, OK, Logan County, OK, Major County, OK, Noble County, OK, Payne County, OK, Roger Mills County, OK, Woods County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 123 km from the middle of the area, began a volume at 02:40 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
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 27, 9:53 PM CDTSevere Thunderstorm WarningOUNEllis, Harper52 min
May 27, 10:26 PM CDTSevere Thunderstorm WarningOUNDewey, Ellis, Major, Woodward49 min
May 27, 11:14 PM CDTSevere Thunderstorm WarningOUNBlaine, Dewey, Harper, Major, Woods, Woodward46 min
May 27, 11:46 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Blaine, Garfield, Kingfisher, Major, Woods44 min
May 28, 12:19 AM CDTSevere Thunderstorm WarningOUNGarfield, Kingfisher, Major26 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

Dodge City, (KDDC), launched 00:00Z, 2.7 hours before the alert went out and 173 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, Dodge City, at 00:00Z on 2017-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 86 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, Dodge City, at 00:00Z on 2017-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.1939587897Sfc1 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
86 J/kg
Mixed-layer CIN
-188 J/kg
Mixed-layer LCL
1608 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
194 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.

IssuedProductOfficeCountiesLasted
May 27, 7:12 PM CDTMesoscale DiscussionSPCBeaver, Cimarron, Texas2 hr
May 27, 8:07 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Carter, Cherokee, Cleveland, Coal and 33 more83 min
May 27, 9:07 PM CDTMesoscale DiscussionSPCBeaver, Dewey, Ellis, Harper, Roger Mills, Woodward53 min
May 27, 10:43 PM CDTMesoscale DiscussionSPCKingfisher, Major, Woodward32 min
May 27, 11:47 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Carter, Cherokee, Choctaw and 17 more58 min
May 28, 12:06 AM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Choctaw, Delaware, Haskell, Latimer and 10 more5 hr
May 28, 12:52 AM CDTMesoscale DiscussionSPCMcCurtain23 min
May 28, 2:53 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Haskell, Latimer, LeFlore and 6 more2 hr

Nearby

Severe Thunderstorm Watches in Oklahoma, 2017Every severe thunderstorm watch in 2017

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.