Alert archive / Oklahoma / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 172

May 11, 20167 counties in Arkansas; 27 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at May 11, 2016, 10:13 PM CDT for 7 counties in Arkansas; 27 counties in Oklahoma. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 11, 2016, 10:13 PM CDT (03:13 UTC)
Expired
May 12, 2016, 5:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 34 counties

Benton County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Madison County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Cleveland County, OK, Coal County, OK, Garvin County, OK, Grady County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Latimer County, OK, LeFlore County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Okfuskee County, OK, Okmulgee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK, Wagoner County, OK

The radar

The Norman radar (KTLX), 92 km from the middle of the area, began a volume at 03:14 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
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
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 11, 10:16 PM CDTSevere Thunderstorm WarningOUNCarter, Jefferson, Stephens44 min
May 11, 10:54 PM CDTSevere Thunderstorm WarningOUNJefferson, Stephens29 min
May 11, 10:56 PM CDTSevere Thunderstorm WarningOUNGarvin, Stephens49 min
May 11, 11:01 PM CDTSevere Thunderstorm WarningOUNCleveland, McClain44 min
May 11, 11:34 PM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie, Seminole26 min
May 11, 11:40 PM CDTSevere Thunderstorm WarningTSACrawford, Washington65 min
May 11, 11:40 PM CDTSevere Thunderstorm WarningOUNCleveland, Garvin, McClain, Pottawatomie35 min
May 12, 12:12 AM CDTSevere Thunderstorm WarningOUNCleveland, McClain, Pontotoc, Pottawatomie, Seminole48 min
May 12, 12:20 AM CDTFlash Flood WarningTSACrawford, Washington3 hr
May 12, 12:33 AM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie42 min
May 12, 12:43 AM CDTSevere Thunderstorm WarningTSACrawford, Washington47 min
May 12, 12:56 AM CDTSevere Thunderstorm WarningOUNHughes, McClain, Pontotoc, Pottawatomie, Seminole49 min
May 12, 1:43 AM CDTSevere Thunderstorm WarningOUNCoal, Hughes, Pontotoc, Pottawatomie, Seminole47 min
May 12, 1:50 AM CDTSevere Thunderstorm WarningTSACrawford, Franklin25 min
May 12, 2:24 AM CDTSevere Thunderstorm WarningOUNAtoka, Coal, Hughes, Pontotoc51 min
May 12, 2:33 AM CDTSevere Thunderstorm WarningTSASequoyah27 min
May 12, 2:37 AM CDTSevere Thunderstorm WarningOUNCotton, Jefferson, Tillman38 min
May 12, 2:42 AM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Jefferson, Stephens33 min
May 12, 2:55 AM CDTSevere Thunderstorm WarningTSASequoyah35 min
May 12, 2:58 AM CDTSevere Thunderstorm WarningTSAPittsburg32 min
May 12, 3:13 AM CDTSevere Thunderstorm WarningOUNCarter, Jefferson, Stephens47 min
May 12, 3:21 AM CDTSevere Thunderstorm WarningTSACrawford, Sebastian14 min
May 12, 3:26 AM CDTSevere Thunderstorm WarningTSAFranklin, Sebastian64 min
May 12, 4:05 AM CDTSevere Thunderstorm WarningTSASebastian40 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, 3.2 hours before the alert went out and 103 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 2016-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1887 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 2016-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 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
1887 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
1366 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 8:11 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 5 more3 hr
May 11, 11:46 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Logan, Scott, Sebastian119 min
May 12, 2:48 AM CDTMesoscale DiscussionSPCCleburne, Conway, Craighead, Faulkner, Garland, Greene and 17 more87 min
May 12, 9:10 AM CDTMesoscale DiscussionSPCCraighead, Crittenden, Cross, Greene, Mississippi, Poinsett95 min
May 12, 2:33 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Desha, Drew and 1 more87 min
May 11, 10:13 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Kiowa, Tillman92 min
May 12, 2:12 AM CDTMesoscale DiscussionSPCCarter, Comanche, Cotton, Jefferson, Stephens, Tillman93 min

Nearby

Severe Thunderstorm Watches in Oklahoma, 2016Severe Thunderstorm Watches in Arkansas, 2016Every severe thunderstorm watch in 2016

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.