Alert archive / Oklahoma / Tornado Watches in 2017

Tornado Watch 279

May 27, 20177 counties in Arkansas; 46 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at May 27, 2017, 4:01 PM CDT for 7 counties in Arkansas; 46 counties in Oklahoma. It was in force for 10 hr.

The area

The outline as issued.

The facts

Issued
May 27, 2017, 4:01 PM CDT (21:01 UTC)
Expired
May 28, 2017, 2:00 AM CDT
In force
10 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 53 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, Atoka County, OK, Bryan County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Cleveland County, OK, Coal County, OK, Craig County, OK, Creek County, OK, Delaware County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, Mayes County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Ottawa 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, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Tulsa radar (KINX), 58 km from the middle of the area, began a volume at 21:01 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
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
90%
One or more hailstones of 2 inches or more
60%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 27, 5:17 PM CDTSevere Thunderstorm WarningTSACraig, Ottawa43 min
May 27, 5:25 PM CDTTornado WarningTSACraig, Ottawa35 min
May 27, 5:36 PM CDTSevere Thunderstorm WarningTSACraig, Ottawa54 min
May 27, 5:56 PM CDTSevere Thunderstorm WarningTSACraig, Ottawa34 min
May 27, 6:16 PM CDTSevere Thunderstorm WarningTSAOsage, Washington44 min
May 27, 6:30 PM CDTSevere Thunderstorm WarningTSAOttawa45 min
May 27, 6:35 PM CDTSevere Thunderstorm WarningOUNCarter55 min
May 27, 6:48 PM CDTSevere Thunderstorm WarningOUNGarvin, Murray57 min
May 27, 6:58 PM CDTSevere Thunderstorm WarningTSANowata, Washington62 min
May 27, 7:15 PM CDTSevere Thunderstorm WarningTSAOttawa20 min
May 27, 7:19 PM CDTSevere Thunderstorm WarningOUNCarter, Johnston, Murray56 min
May 27, 7:25 PM CDTSevere Thunderstorm WarningOUNLincoln41 min
May 27, 7:27 PM CDTSevere Thunderstorm WarningTSACraig, Mayes, Nowata, Rogers63 min
May 27, 7:35 PM CDTSevere Thunderstorm WarningOUNGarvin, Pontotoc, Pottawatomie, Seminole40 min
May 27, 7:36 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Stephens54 min
May 27, 7:41 PM CDTSevere Thunderstorm WarningOUNJohnston, Murray, Pontotoc49 min
May 27, 7:50 PM CDTSevere Thunderstorm WarningTSACreek, Okfuskee55 min
May 27, 7:54 PM CDTTornado WarningOUNJohnston36 min
May 27, 8:09 PM CDTSevere Thunderstorm WarningOUNHughes, Pontotoc, Pottawatomie, Seminole51 min
May 27, 8:10 PM CDTSevere Thunderstorm WarningTSACraig, Delaware, Mayes50 min
May 27, 8:12 PM CDTSevere Thunderstorm WarningOUNAtoka, Coal, Johnston48 min
May 27, 8:22 PM CDTSevere Thunderstorm WarningOUNGarvin, Grady, Stephens68 min
May 27, 8:26 PM CDTTornado Warning Tornado observedTSACreek, Okfuskee49 min
May 27, 8:29 PM CDTSevere Thunderstorm WarningOUNCoal, Johnston, Pontotoc24 min
May 27, 8:33 PM CDTSevere Thunderstorm WarningTSACreek30 min
May 27, 8:38 PM CDTSevere Thunderstorm WarningOUNGarvin, McClain49 min
May 27, 8:43 PM CDTSevere Thunderstorm WarningTSABenton43 min
May 27, 8:43 PM CDTSevere Thunderstorm WarningOUNPottawatomie, Seminole48 min
May 27, 8:52 PM CDTSevere Thunderstorm WarningTSACraig, Delaware, Mayes53 min
May 27, 8:55 PM CDTSevere Thunderstorm WarningOUNAtoka, Coal50 min
May 27, 8:55 PM CDTTornado WarningOUNCarter, Garvin, Murray, Stephens35 min
May 27, 8:55 PM CDTSevere Thunderstorm WarningTSACreek, Tulsa35 min
May 27, 8:58 PM CDTTornado WarningTSAOkfuskee47 min
May 27, 9:01 PM CDTSevere Thunderstorm WarningOUNAtoka, Coal44 min
May 27, 9:06 PM CDTSevere Thunderstorm WarningOUNGarvin, McClain, Pontotoc, Pottawatomie, Seminole24 min
May 27, 9:11 PM CDTSevere Thunderstorm WarningOUNCleveland, McClain, Pottawatomie40 min
May 27, 9:11 PM CDTTornado WarningTSAOkfuskee34 min
May 27, 9:14 PM CDTSevere Thunderstorm WarningTSACreek, Okfuskee, Okmulgee46 min
May 27, 9:20 PM CDTSevere Thunderstorm WarningOUNGarvin, Stephens40 min
May 27, 9:21 PM CDTSevere Thunderstorm WarningTSAMayes, Rogers, Wagoner39 min
May 27, 9:24 PM CDTSevere Thunderstorm WarningTSACarroll66 min
May 27, 9:24 PM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie, Seminole51 min
May 27, 9:24 PM CDTTornado WarningOUNCarter, Garvin, Murray36 min
May 27, 9:28 PM CDTSevere Thunderstorm WarningOUNMcClain, Pontotoc, Pottawatomie, Seminole47 min
May 27, 9:36 PM CDTSevere Thunderstorm WarningTSABenton, Washington54 min
May 27, 9:37 PM CDTSevere Thunderstorm WarningOUNGarvin, Murray68 min
May 27, 9:39 PM CDTFlash Flood WarningTSACreek, Okfuskee4 hr
May 27, 9:40 PM CDTSevere Thunderstorm WarningOUNAtoka, Coal55 min
May 27, 9:42 PM CDTSevere Thunderstorm WarningTSAAdair, Cherokee, Delaware, Mayes, Wagoner63 min
May 27, 9:43 PM CDTSevere Thunderstorm WarningTSAOkfuskee47 min
May 27, 9:46 PM CDTSevere Thunderstorm WarningOUNCarter, Garvin, Murray, Stephens59 min
May 27, 9:46 PM CDTSevere Thunderstorm WarningTSACreek, Muskogee, Okfuskee, Okmulgee, Wagoner44 min
May 27, 9:47 PM CDTTornado WarningOUNMurray28 min
May 27, 10:09 PM CDTFlash Flood WarningOUNCarter, Garvin, Johnston, Murray, Pontotoc, Stephens4 hr
May 27, 10:09 PM CDTTornado WarningOUNCarter, Murray36 min
May 27, 10:13 PM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie, Seminole47 min
May 27, 10:16 PM CDTFlash Flood WarningOUNAtoka, Coal4 hr
May 27, 10:22 PM CDTFlash Flood WarningOUNLincoln, Pottawatomie4 hr
May 27, 10:23 PM CDTSevere Thunderstorm WarningTSAMcIntosh, Muskogee, Okmulgee37 min
May 27, 10:24 PM CDTSevere Thunderstorm WarningOUNCoal, Johnston, Murray, Pontotoc66 min
May 27, 10:25 PM CDTSevere Thunderstorm WarningTSAPittsburg, Pushmataha35 min
May 27, 10:32 PM CDTTornado WarningOUNCarter, Johnston, Murray43 min
May 27, 10:32 PM CDTSevere Thunderstorm WarningTSAOkfuskee43 min
May 27, 10:39 PM CDTSevere Thunderstorm WarningOUNCarter, Garvin, Jefferson, Johnston, Murray, Stephens51 min
May 27, 10:44 PM CDTSevere Thunderstorm WarningTSACraig, Delaware, Mayes, Nowata, Ottawa, Rogers61 min
May 27, 10:48 PM CDTSevere Thunderstorm WarningTSAHaskell, McIntosh, Muskogee, Sequoyah42 min
May 27, 10:50 PM CDTSevere Thunderstorm WarningOUNAtoka, Coal, Hughes, Johnston, Pontotoc70 min
May 27, 11:04 PM CDTTornado WarningOUNJefferson, Stephens26 min
May 27, 11:09 PM CDTSevere Thunderstorm WarningTSACraig, Ottawa51 min
May 27, 11:10 PM CDTSevere Thunderstorm WarningTSAPittsburg, Pushmataha65 min
May 27, 11:17 PM CDTSevere Thunderstorm WarningOUNCarter, Coal, Cotton, Garvin, Jefferson, Johnston and 3 more73 min
May 27, 11:19 PM CDTSevere Thunderstorm WarningTSAAdair, Cherokee, Haskell, LeFlore, Sequoyah41 min
May 27, 11:24 PM CDTTornado WarningOUNCarter, Jefferson36 min
May 27, 11:40 PM CDTSevere Thunderstorm WarningTSACrawford, Sebastian35 min
May 27, 11:48 PM CDTTornado WarningOUNCarter27 min
May 27, 11:50 PM CDTFlash Flood WarningOUNAtoka, Coal, Johnston, Pontotoc4 hr
May 27, 11:53 PM CDTSevere Thunderstorm WarningTSAOttawa37 min
May 27, 11:56 PM CDTSevere Thunderstorm WarningTSACrawford, Franklin, Madison, Washington34 min
May 28, 12:05 AM CDTSevere Thunderstorm WarningTSALatimer, LeFlore, Pittsburg, Pushmataha40 min
May 28, 12:09 AM CDTSevere Thunderstorm WarningOUNCarter, Jefferson, Love81 min
May 28, 12:13 AM CDTFlash Flood WarningOUNCarter, Jefferson, Stephens5 hr
May 28, 12:18 AM CDTTornado WarningOUNJefferson, Love27 min
May 28, 12:19 AM CDTSevere Thunderstorm WarningTSAFranklin, Madison26 min
May 28, 12:25 AM CDTSevere Thunderstorm WarningOUNAtoka, Bryan, Carter, Coal, Johnston, Love and 1 more65 min
May 28, 12:37 AM CDTSevere Thunderstorm WarningTSALatimer, LeFlore, Pushmataha38 min
May 28, 12:39 AM CDTTornado WarningOUNLove36 min
May 28, 12:58 AM CDTSevere Thunderstorm WarningTSASebastian32 min
May 28, 1:04 AM CDTSevere Thunderstorm WarningOUNBryan, Love, Marshall56 min
May 28, 1:15 AM CDTSevere Thunderstorm WarningOUNGarvin, McClain45 min
May 28, 1:34 AM CDTSevere Thunderstorm WarningTSACreek41 min
May 28, 1:57 AM CDTSevere Thunderstorm WarningOUNGarvin, Murray, Pontotoc18 min
May 28, 1:58 AM CDTSevere Thunderstorm WarningOUNCleveland, Garvin, McClain, Pottawatomie32 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 12:00Z, 9.0 hours before the alert went out and 147 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 12:00Z on 2017-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3201 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 12:00Z on 2017-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 201 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
3201 J/kg
Mixed-layer CIN
-231 J/kg
Mixed-layer LCL
1144 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
201 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted.

543 
WWUS20 KWNS 272059
SEL9  
SPC WW 272059
ARZ000-OKZ000-280500-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 279
NWS Storm Prediction Center Norman OK
405 PM CDT Sat May 27 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northwest Arkansas
  Eastern and Central Oklahoma

* Effective this Saturday afternoon from 405 PM until Midnight
  CDT.

* Primary threats include...
  A few tornadoes and a couple intense tornadoes possible
  Widespread large hail and isolated very large hail events to 3
    inches in diameter likely
  Scattered damaging wind gusts to 70 mph likely

SUMMARY...Isolated severe thunderstorms are expected to form over
the eastern half of Oklahoma this afternoon and evening, drifting
into northwest Arkansas.  Very large hail, damaging winds, and
isolated tornadoes will be possible in the strongest cells.

The tornado watch area is approximately along and 75 statute miles
east and west of a line from 30 miles northwest of Grove OK to
Durant OK. For a complete depiction of the watch see the associated
watch outline update (WOUS64 KWNS WOU9).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 275...WW 276...WW
277...WW 278...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 3 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 27030.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 10:36 PM CDTMesoscale DiscussionSPCBenton, Crawford, Madison, Washington54 min
May 27, 12:06 AM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Fulton, Izard and 7 more5 hr
May 27, 2:04 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Fulton, Independence and 10 more116 min
May 27, 3:54 AM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Craighead, Fulton, Greene and 7 more2 hr
May 27, 4:19 AM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 3 more6 hr
May 27, 6:12 AM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Mississippi and 1 more2 hr
May 27, 6:17 PM CDTMesoscale DiscussionSPCBaxter, Boone, Cleburne, Craighead, Fulton, Greene and 12 more58 min
May 27, 9:59 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Boone, Callaway, Camden and 47 more2 hr
May 27, 12:13 PM CDTTornado WatchSPCBarry, Barton, Bates, Benton, Bollinger, Boone and 61 more7 hr
May 27, 1:12 PM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Bollinger, Camden and 50 more93 min
May 27, 1:16 PM CDTMesoscale DiscussionSPCCape Girardeau, Mississippi, New Madrid, Pemiscot, Perry, Scott and 1 more59 min
May 27, 1:36 PM CDTSevere Thunderstorm WatchSPCCape Girardeau, Dunklin, Mississippi, New Madrid, Pemiscot, Saint Charles and 4 more7 hr
May 27, 3:29 PM CDTMesoscale DiscussionSPCBollinger, Butler, Carter, Crawford, Dent, Howell and 14 more91 min
May 27, 3:50 PM CDTMesoscale DiscussionSPCMississippi, New Madrid, Pemiscot, Scott85 min
May 27, 4:24 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Dent, Iron and 8 more66 min
May 27, 5:13 PM CDTSevere Thunderstorm Watch PDSSPCCape Girardeau, Dunklin, Mississippi, New Madrid, Pemiscot, Scott and 1 more7 hr
May 27, 5:56 PM CDTMesoscale DiscussionSPCBenton, Boone, Callaway, Camden, Cole, Cooper and 18 more64 min
May 27, 6:26 PM CDTSevere Thunderstorm WatchSPCBarton, Benton, Boone, Callaway, Camden, Cedar and 28 more3 hr
May 27, 2:04 PM CDTMesoscale DiscussionSPCBlaine, Cherokee, Craig, Creek, Delaware, Garfield and 22 more86 min
May 27, 2:45 PM CDTMesoscale DiscussionSPCCimarron, Texas2 hr
May 27, 4:51 PM CDTMesoscale DiscussionSPCCarter, Cleveland, Coal, Craig, Creek, Garvin and 25 more24 min
May 27, 5:27 PM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Texas6 hr

Nearby

Tornado Watches in Oklahoma, 2017Tornado Watches in Arkansas, 2017Every tornado 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.