Alert archive / Oklahoma / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 368
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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 10, 6:41 PM CDT | Severe Thunderstorm Warning | OUN | Noble, Payne | 49 min |
| Jul 10, 6:45 PM CDT | Severe Thunderstorm Warning | OUN | Blaine, Kingfisher | 45 min |
| Jul 10, 7:12 PM CDT | Severe Thunderstorm Warning | OUN | Logan, Payne | 18 min |
| Jul 10, 7:23 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Payne | 52 min |
| Jul 10, 7:58 PM CDT | Severe Thunderstorm Warning | OUN | Kingfisher, Lincoln, Logan, Oklahoma, Payne | 47 min |
| Jul 10, 8:14 PM CDT | Severe Thunderstorm Warning | OUN | Blaine, Canadian, Kingfisher | 61 min |
| Jul 10, 8:25 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Oklahoma, Pottawatomie | 50 min |
| Jul 10, 8:49 PM CDT | Flash Flood Warning | OUN | Lincoln, Payne | 101 min |
| Jul 10, 8:59 PM CDT | Severe Thunderstorm Warning | OUN | Blaine, Caddo, Canadian, Custer, Grady, Washita | 61 min |
| Jul 10, 9:02 PM CDT | Flash Flood Warning | OUN | Oklahoma | 3 hr |
| Jul 10, 9:11 PM CDT | Severe Thunderstorm Warning | OUN | Cleveland, Lincoln, McClain, Oklahoma, Pottawatomie | 49 min |
| Jul 10, 9:35 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Cleveland, Grady, McClain | 25 min |
| Jul 10, 9:43 PM CDT | Flash Flood Warning | OUN | Oklahoma | 2 hr |
| Jul 10, 10:00 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Grady, Kiowa, Washita | 45 min |
| Jul 10, 10:37 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Comanche, Grady, Kiowa, Washita | 38 min |
| Jul 10, 10:39 PM CDT | Severe Thunderstorm Warning | OUN | Hughes, McClain, Pontotoc, Pottawatomie, Seminole | 51 min |
| Jul 10, 10:48 PM CDT | Severe Thunderstorm Warning | OUN | Garvin, Grady | 42 min |
| Jul 10, 11:12 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Comanche, Grady, Kiowa, Stephens | 63 min |
| Jul 10, 11:31 PM CDT | Flash Flood Warning | OUN | Comanche | 3 hr |
| Jul 10, 11:38 PM CDT | Severe Thunderstorm Warning | OUN | Comanche, Cotton, Jefferson, Stephens | 52 min |
| Jul 10, 11:59 PM CDT | Severe Thunderstorm Warning | OUN | Comanche, Cotton, Kiowa, Tillman | 46 min |
| Jul 11, 12:23 AM CDT | Severe Thunderstorm Warning | OUN | Carter, Comanche, Cotton, Jefferson, Love, Marshall and 1 more | 67 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.
- 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
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.
...ThompsonSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 10, 11:37 AM CDT | Mesoscale Discussion | SPC | Adair, Delaware | 83 min |
| Jul 10, 2:17 PM CDT | Mesoscale Discussion | SPC | Adair, Alfalfa, Blaine, Caddo, Canadian, Cherokee and 42 more | 118 min |
| Jul 10, 3:02 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Cherokee, Craig, Creek, Delaware, Garfield and 23 more | 8 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.