Alert archive / Oklahoma / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 368

July 10, 202125 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Jul 10, 2021, 5:29 PM CDT for 25 counties in Oklahoma. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jul 10, 2021, 5:29 PM CDT (22:29 UTC)
Expired
Jul 11, 2021, 12:45 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 25 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Pottawatomie County, OK, Tillman County, OK, Washita County, OK

The radar

The Altus AFB radar (KFDR), 131 km from the middle of the area, began a volume at 22:29 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
60%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 10, 6:41 PM CDTSevere Thunderstorm WarningOUNNoble, Payne49 min
Jul 10, 6:45 PM CDTSevere Thunderstorm WarningOUNBlaine, Kingfisher45 min
Jul 10, 7:12 PM CDTSevere Thunderstorm WarningOUNLogan, Payne18 min
Jul 10, 7:23 PM CDTSevere Thunderstorm WarningOUNLincoln, Logan, Payne52 min
Jul 10, 7:58 PM CDTSevere Thunderstorm WarningOUNKingfisher, Lincoln, Logan, Oklahoma, Payne47 min
Jul 10, 8:14 PM CDTSevere Thunderstorm WarningOUNBlaine, Canadian, Kingfisher61 min
Jul 10, 8:25 PM CDTSevere Thunderstorm WarningOUNLincoln, Logan, Oklahoma, Pottawatomie50 min
Jul 10, 8:49 PM CDTFlash Flood WarningOUNLincoln, Payne101 min
Jul 10, 8:59 PM CDTSevere Thunderstorm WarningOUNBlaine, Caddo, Canadian, Custer, Grady, Washita61 min
Jul 10, 9:02 PM CDTFlash Flood WarningOUNOklahoma3 hr
Jul 10, 9:11 PM CDTSevere Thunderstorm WarningOUNCleveland, Lincoln, McClain, Oklahoma, Pottawatomie49 min
Jul 10, 9:35 PM CDTSevere Thunderstorm WarningOUNCaddo, Cleveland, Grady, McClain25 min
Jul 10, 9:43 PM CDTFlash Flood WarningOUNOklahoma2 hr
Jul 10, 10:00 PM CDTSevere Thunderstorm WarningOUNCaddo, Grady, Kiowa, Washita45 min
Jul 10, 10:37 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Grady, Kiowa, Washita38 min
Jul 10, 10:39 PM CDTSevere Thunderstorm WarningOUNHughes, McClain, Pontotoc, Pottawatomie, Seminole51 min
Jul 10, 10:48 PM CDTSevere Thunderstorm WarningOUNGarvin, Grady42 min
Jul 10, 11:12 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Grady, Kiowa, Stephens63 min
Jul 10, 11:31 PM CDTFlash Flood WarningOUNComanche3 hr
Jul 10, 11:38 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Jefferson, Stephens52 min
Jul 10, 11:59 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Kiowa, Tillman46 min
Jul 11, 12:23 AM CDTSevere Thunderstorm WarningOUNCarter, Comanche, Cotton, Jefferson, Love, Marshall and 1 more67 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, 10.5 hours before the alert went out and 129 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 2021-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1249 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 2021-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 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
1249 J/kg
Mixed-layer CIN
-280 J/kg
Mixed-layer LCL
670 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

895 
WWUS20 KWNS 102226
SEL8  
SPC WW 102226
OKZ000-110500-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 368
NWS Storm Prediction Center Norman OK
525 PM CDT Sat Jul 10 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Parts of central and western Oklahoma

* Effective this Saturday afternoon from 525 PM until Midnight
  CDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph likely
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible

SUMMARY...Thunderstorm development is expected by 6-7pm CDT along a
cold front from north central into west central Oklahoma.  The storm
environment favors broken bands of multicell clusters and supercells
capable of producing damaging winds and large hail, and the severe
threat will persist into the early overnight hours as storms spread
southeastward across central and southwest Oklahoma.

The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 45 miles west southwest
of Clinton OK to 45 miles northeast of Oklahoma City OK. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 365...WW 366...WW 367...

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
32020.

...Thompson

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 10, 11:37 AM CDTMesoscale DiscussionSPCAdair, Delaware83 min
Jul 10, 2:17 PM CDTMesoscale DiscussionSPCAdair, Alfalfa, Blaine, Caddo, Canadian, Cherokee and 42 more118 min
Jul 10, 3:02 PM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Craig, Creek, Delaware, Garfield and 23 more8 hr

Nearby

Severe Thunderstorm Watches in Oklahoma, 2021Every severe thunderstorm watch in 2021

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.