Alert archive / Oklahoma / Tornado Watches in 2018

Tornado Watch 66

May 2, 201836 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at May 2, 2018, 8:05 PM CDT for 36 counties in Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 2, 2018, 8:05 PM CDT (01:05 UTC)
Expired
May 3, 2018, 2:13 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt
All 36 counties

Adair County, OK, Atoka County, OK, Bryan County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Craig County, OK, Creek County, OK, Delaware County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, Mayes County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Okmulgee County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Norman radar (KTLX), 94 km from the middle of the area, began a volume at 01:06 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
20%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 2, 8:17 PM CDTSevere Thunderstorm WarningOUNCarter, Cleveland, Garvin, Grady, McClain, Murray and 2 more58 min
May 2, 8:57 PM CDTSevere Thunderstorm WarningOUNCleveland, Lincoln, Oklahoma, Pottawatomie, Seminole48 min
May 2, 8:57 PM CDTSevere Thunderstorm WarningOUNCleveland, Garvin, McClain, Pontotoc, Pottawatomie, Seminole63 min
May 2, 9:29 PM CDTSevere Thunderstorm WarningTSACreek, Osage, Pawnee46 min
May 2, 9:36 PM CDTSevere Thunderstorm WarningTSACreek, Okfuskee, Okmulgee54 min
May 2, 9:43 PM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie, Seminole32 min
May 2, 9:44 PM CDTTornado WarningTSAOsage, Pawnee31 min
May 2, 9:48 PM CDTSevere Thunderstorm WarningOUNCarter, Jefferson, Johnston, Love, Marshall, Murray and 1 more42 min
May 2, 9:50 PM CDTSevere Thunderstorm WarningOUNHughes, Seminole55 min
May 2, 10:08 PM CDTTornado WarningTSAOsage48 min
May 2, 10:10 PM CDTSevere Thunderstorm WarningTSACreek, Osage, Pawnee, Tulsa, Washington65 min
May 2, 10:13 PM CDTSevere Thunderstorm WarningTSACreek, McIntosh, Mayes, Muskogee, Okfuskee, Okmulgee and 3 more62 min
May 2, 10:26 PM CDTSevere Thunderstorm WarningOUNAtoka, Carter, Coal, Johnston, Love, Marshall and 2 more49 min
May 2, 10:43 PM CDTSevere Thunderstorm WarningTSACraig, Nowata, Rogers, Washington47 min
May 2, 11:11 PM CDTSevere Thunderstorm WarningOUNAtoka, Coal, Hughes, Johnston, Pontotoc, Seminole64 min
May 2, 11:27 PM CDTSevere Thunderstorm WarningTSACraig, Ottawa48 min
May 2, 11:34 PM CDTSevere Thunderstorm WarningTSAPittsburg56 min
May 2, 11:54 PM CDTSevere Thunderstorm WarningTSAAdair, Cherokee41 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, 1.1 hours before the alert went out and 104 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 2018-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 826 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 2018-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 207 square meters per square second.19395878Sfc1 km3 km6 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
826 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
207 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.7
Supercell composite
5.3

Open this sounding in Storm Lab

The text

As transmitted.

027 
WWUS20 KWNS 030101
SEL6  
SPC WW 030101
OKZ000-030800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 66
NWS Storm Prediction Center Norman OK
805 PM CDT Wed May 2 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern and eastern Oklahoma

* Effective this Wednesday night and Thursday morning from 805 PM
  until 300 AM CDT.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging winds likely with isolated significant gusts
    to 75 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...A broken belt of strong-severe thunderstorms, with bow
echoes and perhaps an embedded supercell or two, will move into the
watch area over the next few hours.  Damaging gusts, sporadic severe
hail, and a few embedded tornadoes are possible.

The tornado watch area is approximately along and 65 statute miles
east and west of a line from 40 miles east southeast of Ardmore OK
to 30 miles east northeast of Bartlesville OK. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU6).

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 61...WW 62...WW 63...WW
64...WW 65...

AVIATION...TORNADOES and A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE and ALOFT TO 1.5 INCHES. EXTREME TURBULENCE and SURFACE
WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 24035.


...Edwards

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 7:14 PM CDTMesoscale DiscussionSPCAtoka, Cherokee, Coal, Craig, Creek, Delaware and 18 more2 hr
May 2, 11:09 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Carter, Cherokee, Coal and 26 more96 min
May 3, 4:06 AM CDTMesoscale DiscussionSPCBryan, Carter, Cleveland, Coal, Comanche, Cotton and 14 more114 min
May 3, 5:18 AM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Coal, Comanche, Cotton and 11 more6 hr
May 3, 9:02 AM CDTMesoscale DiscussionSPCAdair, Cherokee, Haskell, Hughes, Latimer, LeFlore and 4 more88 min
May 3, 9:55 AM CDTMesoscale DiscussionSPCCarter, Coal, Comanche, Cotton, Garvin, Jefferson and 7 more65 min
May 3, 12:35 PM CDTMesoscale DiscussionSPCChoctaw, LeFlore, McCurtain85 min

Nearby

Tornado Watches in Oklahoma, 2018Every tornado watch in 2018

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.