Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 364, NWS Tulsa, OK

August 31, 2020McIntosh County, Muskogee County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Aug 31, 2020, 5:10 AM CDT for McIntosh County, Muskogee County, Oklahoma. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 31, 2020, 5:10 AM CDT (10:10 UTC)
Expired: Aug 31, 2020, 6:00 AM CDT
In force: 50 min
Issued by: NWS Tulsa, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties McIntosh County, OK, Muskogee County, OK

The radar

The Tulsa radar (KINX), 76 km from the middle of the area, began a volume at 10:13 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.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 10.2 hours before the alert went out and 173 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1694 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 1454 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 6.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 31, 3:27 AM CDT, 1 hour 43 minutes earlier.

Area forecast discussion, Aug 31, 3:27 AM CDT, 1 hour 43 minutes before

Area Forecast Discussion
National Weather Service Tulsa OK
327 AM CDT Mon Aug 31 2020

.DISCUSSION...
Widely scattered showers/thunderstorms starting to develop across
NE OK in response to approaching upper wave in stronger low level
jet axis. Moderate instability/fairly steep mid level lapse rates
coupled with deep layer shear around 35 knots will support a
large hail/damaging wind threat across portions of eastern
Oklahoma this morning. In addition, with PWAT around 2 inches,
locally heavy rainfall is likely in the stronger storms. This
activity will begin to shift east into northwest Arkansas this
morning and will likely begin to weaken as storms move into a more
stable air- mass.

Cold front will push into far northeast Oklahoma this afternoon
with atmosphere becoming very unstable as low level moisture pools
ahead of boundary with dew-points climbing in the upper 70s. Weak
surface low progged along boundary may back winds enough for a
limited tornado threat, however main threats will again be large
hail/damaging winds. Thunderstorms are expected to increase in
coverage through the evening hours with activity spreading into
southeast Oklahoma/northwest Arkansas. With rainfall rates in the
1-2 inch per hour range in the stronger storms, localized flooding
will be possible and a flash flood watch may be needed for some
areas, especially south of I-44 where FFG has been lowered from
the previous rainfall over the last few days.

Multiple rounds of thunderstorms with a heavy rainfall will remain
possible Tuesday into Wednesday as upper trough axis approaches
from the northwest with upper low moving over the Four Corners
region and into west Texas. More widespread flooding will be
possible during this time including some main-stem river flooding.
Depending on how quickly upper low progresses, precipitation
chances may continue across southeast Oklahoma/northwest Arkansas
Thursday with a few lingering showers into Friday across the
south as front pushes south of the Red River. Cooler and less
humid conditions expected over the weekend as weak surface ridge
axis remains over NW AR.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   92  72  84  71 /  40  70  80  60
FSM   90  73  83  72 /  50  60  90  70
MLC   91  72  82  70 /  50  70  90  80
BVO   91  68  84  68 /  40  70  80  50
FYV   87  68  81  68 /  50  70  90  60
BYV   89  69  83  69 /  40  70  90  60
MKO   88  71  82  70 /  50  60  90  70
MIO   88  69  83  69 /  30  70  90  40
F10   90  70  82  69 /  50  70  90  70
HHW   92  73  84  72 /  40  80  80  80

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&

LONG TERM....12

Hazardous weather outlook, Aug 31, 4:55 AM CDT, 15 minutes before

Hazardous Weather Outlook
National Weather Service Tulsa OK
455 AM CDT Mon Aug 31 2020

ARZ001-002-010-011-019-020-029-OKZ049-053>076-011000-
Adair OK-Benton AR-Carroll AR-Cherokee OK-Choctaw OK-Craig OK-
Crawford AR-Creek OK-Delaware OK-Franklin AR-Haskell OK-Latimer OK-
Le Flore OK-Madison AR-Mayes OK-McIntosh OK-Muskogee OK-Nowata OK-
Okfuskee OK-Okmulgee OK-Osage OK-Ottawa OK-Pawnee OK-Pittsburg OK-
Pushmataha OK-Rogers OK-Sebastian AR-Sequoyah OK-Tulsa OK-Wagoner OK-
Washington OK-Washington AR-
455 AM CDT Mon Aug 31 2020

...SEVERE WEATHER LIKELY TODAY...

This Outlook is for Northwest and West Central Arkansas as well as
much of Eastern Oklahoma.

.DAY ONE...Today and Tonight.

TORNADO.
	RISK...Limited.
	AREA...Northeast Oklahoma.
	ONSET...Late afternoon.

SEVERE THUNDERSTORM.
	RISK...Elevated.
	AREA...Eastern Oklahoma and northwest Arkansas.
	ONSET...Ongoing.

FLASH FLOOD.
	RISK...Limited.
	AREA...Eastern Oklahoma and northwest Arkansas.
	ONSET...Late Afternoon.

HEAVY RAIN.
	RISK...Elevated.
	AREA...Eastern Oklahoma and northwest Arkansas.
	ONSET...Ongoing.

DANGEROUS HEAT.
	RISK...Elevated.
	AREA...Eastern Oklahoma and west-central Arkansas.
	ONSET...This afternoon.

DISCUSSION...
Clusters of strong to severe thunderstorms have developed early
this morning across portions of northeast Oklahoma and west-
central Arkansas. Large hail and damaging winds will be likely in
the stronger clusters. Storms are expected to weaken around mid
morning as the low level jet begins to decrease.

Additional severe thunderstorm development is expected across portions
of northeast Oklahoma by late afternoon or early evening as a cold
front moves into the area. This activity will likely spread into
southeast Oklahoma and northwest Arkansas this evening into the
overnight hours with large hail and damaging winds. In addition,
very heavy rainfall is likely with localized flash flooding. A
flash flood watch may be issued later today as the axis of heavy
rainfall becomes more certain.

SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
Activation of the Regional Spotter Network Likely.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.
TUESDAY...Severe Thunderstorm Potential...Heavy Rain Potential.
WEDNESDAY...Thunderstorm Potential...Heavy Rain Potential.
THURSDAY AND FRIDAY...Thunderstorm Potential.
SATURDAY...No Hazards.
SUNDAY...Thunderstorm Potential.

EXTENDED DISCUSSION...
The unsettled weather pattern will continue on Tuesday and Wednesday
as an upper level trough approaches from the northwest. Multiple
rounds of strong thunderstorms with very heavy rainfall will be
possible including the potential for flash flooding. Main-stem
river flooding may also become an issue as more widespread rainfall
occurs over the duration of the event.

weather.gov/tulsa contains additional information.

In the hours before

Special weather statement, Aug 31, 3:55 AM CDT, 1 hour 15 minutes before

Special Weather Statement
National Weather Service Tulsa OK
355 AM CDT Mon Aug 31 2020

OKZ069-070-072-074-310930-
Haskell OK-Adair OK-Muskogee OK-Sequoyah OK-
355 AM CDT Mon Aug 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN HASKELL...WESTERN
SEQUOYAH...SOUTHWESTERN ADAIR AND EAST CENTRAL MUSKOGEE COUNTIES
UNTIL 430 AM CDT...

At 355 AM CDT, a strong thunderstorm was located 3 miles east of
Gore, moving southeast at 25 mph.

Winds in excess of 40 mph and hail up to one half inch in
diameter will be possible with this storm.

Locations in or near the path include...
Sallisaw...                       Vian...
Gore...                           Webbers Falls...
Marble City...                    Tamaha...
Brushy Lake State Park...         Brushy...
Lake Tenkiller State Park...      Mc Key...
Box...

This includes Interstate 40 in Oklahoma between mile markers 284 and
310.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 3535 9476 3535 9478 3533 9479 3547 9519
      3563 9507 3564 9495 3564 9481 3565 9481
      3567 9462
TIME...MOT...LOC 0855Z 293DEG 23KT 3553 9506

Snider

Special weather statement, Aug 31, 4:16 AM CDT, 54 minutes before

Special Weather Statement
National Weather Service Tulsa OK
416 AM CDT Mon Aug 31 2020

OKZ060-064-066-067-070-310945-
Tulsa OK-Muskogee OK-Okmulgee OK-Creek OK-Wagoner OK-
416 AM CDT Mon Aug 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CREEK...SOUTHWESTERN
WAGONER...NORTHWESTERN MUSKOGEE...NORTHEASTERN OKMULGEE AND
SOUTHEASTERN TULSA COUNTIES UNTIL 445 AM CDT...

At 415 AM CDT, a strong thunderstorm was located near Sapulpa, moving
east at 25 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations in or near the path include...
Tulsa...                          Broken Arrow...
Bixby...                          Sapulpa...
Jenks...                          Glenpool...
Coweta...                         Haskell...
Kiefer...                         Mounds...
Kellyville...                     Jenks Riverside Airport...
Stonebluff...                     Oneta...
Liberty...                        Jamesville...
Hectorville...                    Leonard...
Choska...

This includes Interstate 44 between mile markers 201 and 214.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3588 9629 3605 9621 3606 9562 3569 9562
TIME...MOT...LOC 0915Z 271DEG 23KT 3598 9609

Snider

Local storm report, Aug 31, 4:35 AM CDT, 35 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
435 AM CDT MON AUG 31 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0426 AM     HAIL             HECTORVILLE             35.84N 95.93W
08/31/2020  E0.88 INCH       OKMULGEE           OK   TRAINED SPOTTER

            SPOTTER REPORTED PEA TO NICKEL SIZE HAIL IN HECTORVILLE.

&&

SNIDER

Special weather statement, Aug 31, 4:39 AM CDT, 31 minutes before

Special Weather Statement
National Weather Service Tulsa OK
439 AM CDT Mon Aug 31 2020

ARZ019-020-311015-
Franklin AR-Crawford AR-
439 AM CDT Mon Aug 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL FRANKLIN AND NORTHEASTERN
CRAWFORD COUNTIES UNTIL 515 AM CDT...

At 439 AM CDT, a strong thunderstorm was located 3 miles northwest of
Fern, moving southeast at 20 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations in or near the path include...
Ozark...                          Mountainburg...
Mulberry...                       Fern...
Jethro...                         Barnes...
Bidville...                       Watalula...
Piney...                          Toney...
Locke...                          Turners Bend...
Cecil...                          Lonelm...
Cravens...                        Paradise...

This includes Interstate 40 in Arkansas between mile markers 23 and
37.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 3565 9417 3576 9399 3562 9370 3537 9392
TIME...MOT...LOC 0939Z 308DEG 19KT 3568 9404

Snider

Special weather statement, Aug 31, 4:58 AM CDT, 12 minutes before

Special Weather Statement
National Weather Service Tulsa OK
458 AM CDT Mon Aug 31 2020

OKZ059-060-064-066-311045-
Tulsa OK-Okmulgee OK-Pawnee OK-Creek OK-
458 AM CDT Mon Aug 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN CREEK...SOUTH CENTRAL
PAWNEE...NORTHWESTERN OKMULGEE AND SOUTHWESTERN TULSA COUNTIES UNTIL
545 AM CDT...

At 458 AM CDT, strong thunderstorms were located along a line
extending from 2 miles northwest of Yale to 5 miles south of
Kellyville. Movement was southeast at 25 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
these storms.

Locations in or near the path include...
Sapulpa...                        Glenpool...
Mannford...                       Drumright...
Kiefer...                         Mounds...
Kellyville...                     Oilton...
Jennings...                       Hallett...
Terlton...                        Maramec...
Liberty...                        Silver City...

This includes Interstate 44 between mile markers 194 and 211.

LAT...LON 3630 9669 3598 9602 3582 9601 3581 9627
      3599 9662 3616 9662 3616 9682 3617 9682
TIME...MOT...LOC 0958Z 296DEG 23KT 3613 9674 3586 9624

Special weather statement, Aug 31, 5:01 AM CDT, 9 minutes before

Special Weather Statement
National Weather Service Tulsa OK
501 AM CDT Mon Aug 31 2020

ARZ019-029-OKZ068-069-072-074-076-311045-
Sebastian AR-Crawford AR-Haskell OK-Adair OK-Sequoyah OK-Cherokee OK-
Le Flore OK-
501 AM CDT Mon Aug 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN CRAWFORD...WESTERN
SEBASTIAN...NORTHEASTERN HASKELL...SEQUOYAH...SOUTHWESTERN ADAIR...
NORTHEASTERN LE FLORE AND SOUTHEASTERN CHEROKEE COUNTIES UNTIL 545 AM
CDT...

At 501 AM CDT, strong thunderstorms were located along a line
extending from 2 miles west of Brushy Lake State Park to 4 miles
south of Roland. Movement was southeast at 30 mph.

Penny size hail and winds in excess of 40 mph will be possible with
these storms.

Locations in or near the path include...
Fort Smith...                     Van Buren...
Sallisaw...                       Cedarville...
Greenwood...                      Alma...
Barling...                        Pocola...
Muldrow...                        Roland...
Lavaca...                         Spiro...
Arkoma...                         Mansfield...
Hackett...                        Huntington...
Bonanza...                        Midland...
Gans...                           Marble City...

This includes the following highways,
 Interstate 40 in Arkansas between mile markers 0 and 15.
 Interstate 40 in Oklahoma between mile markers 297 and 328.
 Interstate 540 between mile markers 1 and 14.
 Interstate 49 near mile marker 22.

LAT...LON 3508 9420 3508 9422 3506 9425 3506 9423
      3500 9423 3536 9497 3573 9492 3549 9416
TIME...MOT...LOC 1001Z 317DEG 26KT 3555 9487 3535 9453

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 31, 3:06 AM CDT	Special Weather Statement	TSA	Creek, Tulsa	24 min
Aug 31, 3:29 AM CDT	Special Weather Statement	TSA	Tulsa	46 min
Aug 31, 3:48 AM CDT	Special Weather Statement	TSA	Okmulgee	42 min
Aug 31, 3:55 AM CDT	Special Weather Statement	TSA	Sequoyah	35 min
Aug 31, 4:16 AM CDT	Special Weather Statement	TSA	Okmulgee	29 min
Aug 31, 4:19 AM CDT	Severe Thunderstorm Warning	TSA	Creek, Muskogee, Okmulgee, Tulsa, Wagoner	41 min
Aug 31, 4:43 AM CDT	Severe Thunderstorm Warning	TSA	Muskogee, Okmulgee, Wagoner	62 min
Aug 31, 4:58 AM CDT	Special Weather Statement	TSA	Creek	47 min
Aug 31, 5:01 AM CDT	Special Weather Statement	TSA	Sequoyah	44 min
Aug 31, 5:45 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, LeFlore, Muskogee, Sequoyah	45 min
Aug 31, 5:49 AM CDT	Special Weather Statement	TSA	Adair	26 min
Aug 31, 6:09 AM CDT	Flash Flood Warning	TSA	LeFlore, Sequoyah	3 hr
Aug 31, 6:14 AM CDT	Severe Thunderstorm Warning	TSA	Adair, Haskell, LeFlore, Sequoyah	61 min
Aug 31, 7:16 AM CDT	Special Weather Statement	TSA	LeFlore	44 min
Aug 31, 7:30 AM CDT	Flash Flood Warning	TSA	LeFlore	4 hr
Aug 31, 9:02 AM CDT	Flash Flood Warning	TSA	LeFlore, Sequoyah	3 hr
Aug 31, 2:06 PM CDT	Flash Flood Watch	TSA	Adair, Cherokee, Choctaw, Creek, Haskell, Latimer and 8 more	55 hr
Aug 31, 2:11 PM CDT	River Flood Warning	TSA	LeFlore	4 days
Aug 31, 4:53 PM CDT	Special Weather Statement	TSA	Osage	37 min
Aug 31, 5:28 PM CDT	Severe Thunderstorm Warning	TSA	Pawnee	62 min
Aug 31, 5:32 PM CDT	Special Weather Statement	TSA	Osage	28 min
Aug 31, 6:05 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Pawnee	40 min
Aug 31, 6:06 PM CDT	Special Weather Statement	TSA	Osage	24 min
Aug 31, 6:09 PM CDT	Severe Thunderstorm Warning	TSA	Osage	51 min
Aug 31, 6:36 PM CDT	Special Weather Statement	TSA	Pawnee	24 min
Aug 31, 6:39 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Washington	51 min
Aug 31, 4:39 AM CDT	Special Weather Statement	TSA	Franklin	36 min
Aug 31, 7:01 AM CDT	Severe Thunderstorm Warning	TSA	Crawford, Franklin, Sebastian	44 min
Aug 31, 7:46 AM CDT	Special Weather Statement	TSA	Sebastian	14 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2020 Every severe thunderstorm warning in 2020

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.