Alert archive / Oklahoma / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 92

April 27, 201457 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Apr 27, 2014, 5:33 AM CDT for 57 counties in Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 27, 2014, 5:33 AM CDT (10:33 UTC)
Expired
Apr 27, 2014, 12:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 57 counties

Alfalfa County, OK, Atoka County, OK, Blaine County, OK, Bryan County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Craig County, OK, Creek County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Kay County, OK, Kingfisher County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Major County, OK, Marshall County, OK, Mayes County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Noble County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK, Tillman County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Norman radar (KTLX), 50 km from the middle of the area, began a volume at 10:34 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
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
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 27, 5:38 AM CDTSevere Thunderstorm WarningOUNComanche, Grady52 min
Apr 27, 5:54 AM CDTSevere Thunderstorm WarningOUNCanadian, Grady, Kingfisher, Logan, Oklahoma51 min
Apr 27, 6:20 AM CDTSevere Thunderstorm WarningOUNCanadian, Kingfisher, Logan, Oklahoma40 min
Apr 27, 6:36 AM CDTSevere Thunderstorm WarningOUNGarfield, Logan, Noble, Payne24 min
Apr 27, 6:38 AM CDTSevere Thunderstorm WarningOUNGarfield, Kingfisher, Logan37 min
Apr 27, 7:08 AM CDTSevere Thunderstorm WarningOUNCanadian, Logan, Oklahoma22 min
Apr 27, 7:24 AM CDTSevere Thunderstorm WarningOUNLogan, Noble, Payne51 min
Apr 27, 7:29 AM CDTSevere Thunderstorm WarningOUNLincoln, Logan, Oklahoma, Payne46 min
Apr 27, 7:45 AM CDTSevere Thunderstorm WarningOUNCotton, Jefferson, Stephens45 min
Apr 27, 7:58 AM CDTSevere Thunderstorm WarningOUNAtoka, Coal, Johnston, Marshall, Pontotoc47 min
Apr 27, 7:59 AM CDTSevere Thunderstorm WarningTSACreek, Osage, Pawnee46 min
Apr 27, 8:01 AM CDTSevere Thunderstorm WarningOUNLogan, Oklahoma29 min
Apr 27, 8:20 AM CDTSevere Thunderstorm WarningTSAOsage25 min
Apr 27, 8:36 AM CDTSevere Thunderstorm WarningOUNLincoln, Payne39 min
Apr 27, 8:47 AM CDTSevere Thunderstorm WarningOUNBryan, Marshall43 min
Apr 27, 9:14 AM CDTSevere Thunderstorm WarningOUNLincoln46 min
Apr 27, 9:36 AM CDTSevere Thunderstorm WarningOUNAtoka39 min
Apr 27, 9:39 AM CDTSevere Thunderstorm WarningTSACreek, Osage, Pawnee51 min
Apr 27, 10:08 AM CDTSevere Thunderstorm WarningTSALatimer, Pittsburg, Pushmataha52 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 00:00Z, 10.6 hours before the alert went out and 63 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, Norman, OK at 00:00Z on 2014-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1087 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, Norman, OK at 00:00Z on 2014-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 129 square meters per square second.193958Sfc1 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
1087 J/kg
Mixed-layer CIN
-181 J/kg
Mixed-layer LCL
1782 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
235 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 5:09 AM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Cleveland, Comanche and 26 more96 min
Apr 27, 7:55 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Canadian, Carter, Cherokee, Choctaw and 45 more95 min
Apr 27, 10:06 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Cherokee, Choctaw, Coal, Craig and 16 more84 min
Apr 27, 12:25 PM CDTMesoscale DiscussionSPCLeFlore, McCurtain, Sequoyah2 hr
Apr 27, 1:46 PM CDTTornado WatchSPCAdair, Cherokee, Choctaw, Craig, Delaware, Haskell and 11 more9 hr
Apr 27, 3:36 PM CDTTornado Watch PDSSPCLeFlore, McCurtain7 hr
Apr 27, 4:52 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Haskell, LeFlore, McCurtain, Sequoyah53 min
Apr 27, 4:57 PM CDTMesoscale DiscussionSPCOttawa63 min
Apr 27, 6:10 PM CDTMesoscale DiscussionSPCOttawa95 min
Apr 27, 6:11 PM CDTMesoscale DiscussionSPCAdair, Haskell, LeFlore, McCurtain, Sequoyah64 min
Apr 27, 6:26 PM CDTTornado WatchSPCAdair, Cherokee, Choctaw, Delaware, Haskell, Latimer and 2 more8 hr

Nearby

Severe Thunderstorm Watches in Oklahoma, 2014Every severe thunderstorm watch in 2014

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.