An outbreak of severe thunderstorms and tornadoes occurred during the afternoon and evening of May 20th. A funnel was sighted over Pryor initially and then a tornado touched down 3 miles southwest of Spavinaw at 11:10 pm CST where it struck a farmstead and produced $40,000 in damages to the farm home and destroyed all of the outbuildings. The tornado moved northeastward through Spavinaw and then struck several more farmsteads northeast of the city. Extensive damage occurred along the tornado's path and one person was injured when a house was destroyed in Spavinaw. The tornado continued to the northeast into Delaware County and damaged 3 more farmsteads near the Deerlick community or 4 miles northeast of Jay. There were reports of numerous funnels in the two-county area.

The tornado moved northeastward from northeast of Strang and destroyed 3 fishing camps near Disney to near Dennis, before dissipating just west of Grove. Over 40 families had their homes destroyed. Two people were injured in a demolished farm home northeast of Strang and one person was injured by flying glass at one of the fishing camps. Trees and utility line blocked local roads and a small amount of large hail fell in the area.

A tornado touched down about 4 miles north of Pensacola in Mayes County at 4:50 pm CST and moved northeastward along a nearly continuous path. At 5:20 pm CST, it leveled a mini-mart near Ketchum and the intersection of OK State Highways 82 and 85 in Craig County. Four people were injured by flying debris in the Ketchum area in Craig County as the tornado progressed to the northeast. Three of the injured were inside one car, and the fourth was hospitalized with severe lacerations.

The tornado then moved through the Cleora area to Bernice along the western shores of Grand Lake in Delaware County before dissipating in southern Ottawa County at 5:45 pm CST. Twenty residences were damaged in the Grand Lake resort area south of Cleora, and one mobile home park was destroyed at Bernice. One man was treated for injuries after he was pummeled by baseball size hail, but he was not hospitalized. For the entire path of the tornado, a total of 11 homes were destroyed, 6 other homes had major damage, and 40 homes received minor damage. In addition, a total of 28 mobile homes were destroyed while 25 more were damaged. Hail ranging from golf ball to baseball size was reported with the storm. The tornado was occasionally multi-vortex in nature as some people reported seeing 3 funnels while others saw only one funnel.

Thunderstorms in northeastern Oklahoma spawned one tornado and produced hail up to the size of golf balls. At 6:30 pm CST, a tornado touched down 3.5 miles north-northwest of Moseley, moved southward, and dissipated at 6:45 pm CST 0.8 miles southwest of Moseley. The damage path was between 50 and 100 yards wide and 5 miles long. Three mobile homes were destroyed, and one occupant in the mobile homes was slightly injured. Seven homes were damaged and 5 barns were damaged or destroyed. Moseley is 4 miles east of Colcord.

A F1 tornado touched down near Flint on Flint Creek or about 5 miles east southeast of community of Kansas. The tornado was on the ground for 3.2 miles and was 200 yards wide. Approximated 30-40 mobile homes and travel trailers were damaged or destroyed. Several automobiles were also damaged. Two people were taken to a hospital due to injuries. However, they were released later in the day.

Thunderstorms developed ahead of a dry line late in the afternoon on March 12th. The atmosphere ahead of the dry line was highly unstable and had strong low level wind shear. The combination of the instability and wind shear promoted the development of supercell thunderstorms, which moved east-northeast across northeastern Oklahoma and northwestern Arkansas during the evening. The southernmost supercell produced four tornadoes. The tornadoes were on the ground for a combined 65 miles.

This tornado touched down in northwestern Cherokee County and moved east-northeast producing up to F1 damage in the county as assessed by a survey team. In Cherokee County, several homes received minor damage, outbuildings were destroyed, power lines were downed, and numerous trees were snapped or uprooted.

The tornado continued into southern Delaware County. Damage suggested the tornado widened and strengthened as it moved through southern Delaware County reaching a maximum width of around 1/4 of a mile. The tornado damaged 95 homes, destroying 42 of those homes. Five businesses were also damaged. Numerous trees were snapped or uprooted and about 100 power poles were downed, which resulted in more than 5000 people losing power as a result of the storm. The worst damage from this tornado was found from near Twin Oaks to about 4 miles west-southwest of Colcord. The tornado injured eight people in Delaware County.

The supercell thunderstorm that produced the previous tornado cycled and a second tornado formed southeast of Colcord while the first tornado was dissipating northeast of town. This tornado destroyed two chicken houses, damaged homes, destroyed outbuildings, snapped or uprooted numerous trees, and downed power poles.

The tornado moved into western Benton County, Arkansas south of AR State Highway 12, where damage suggested the tornado strengthened considerably. A mobile home was destroyed, a pickup truck was rolled and destroyed, and several homes sustained major damage to their roofs near Bloomfield, where damage was rated at F2. Damage was more extensive in and around Gentry and Centerton where 75 homes were damaged or destroyed. Damage in this area was rated F3. Twelve people were injured by the tornado.

Low pressure was centered over southern Kansas during the early afternoon of April 14th with a sharp dryline extending from the low pressure system through central Oklahoma. A moist and very unstable air mass was in place across eastern Oklahoma ahead of the dryline. Severe thunderstorms developed along the dryline during the afternoon and moved into eastern Oklahoma during the early evening hours. Large hail up to grapefruit size, damaging wind gusts, and numerous tornadoes occurred as the storms moved through the region.

This tornado destroyed a mobile home, injuring three people. Several other mobile homes were severely damaged. Trees were snapped or uprooted. Maximum estimated wind in the tornado based on this damage was about 125 mph.

A very moist and very unstable air mass developed across eastern Oklahoma on the afternoon and evening of May 22nd as a dry line moved into the area from the west. Severe thunderstorms, including supercells, developed ahead of the dry line and moved across the area producing tornadoes, large hail up to softball size, and damaging wind gusts.

The tornado developed about 2.5 miles west-southwest of Zena, moved east-northeast across Grand Lake and then south of Zena crossing OK State Highway 59 just north of the intersection with OK State Highway 127. Permanent homes were damaged, barns and outbuildings were destroyed, mobile homes were severely damaged, and large trees were snapped or uprooted. The intensity and width of the tornado increased east of OK State Highway 59 where several permanent homes were severely damaged, two double wide mobile homes were destroyed with only small pieces of debris remaining hundreds of yards from the homesite, and many large trees were snapped or uprooted. This extent of damage continued to the state line where a permanent home was severely damaged, two mobile homes were destroyed, and a steel-framed building was destroyed. Two people were injured in the permanent home. Maximum estimated wind in the tornado based on this damage was about 140 mph. The tornado continued into McDonald County, Missouri for about another mile before dissipating.

A storm survey concluded that an EF-3 tornado crossed into McDonald County from adjacent Delaware County, Oklahoma. The tornado crossed Stateline Road 2.8 miles north of Southwest City, Missouri at 7:26 pm CST and destroyed a single-family resident and vehicles near the residence. The vehicles rolled up to 200 yards away from the house. Several trees were uprooted along the path of the tornado as it tracked southeast towards chicken houses near the intersection of MO State Highway 43 and Farm Road 4385. The tornado lifted right before reaching MO State Highway 43 about 2.2 miles north northeast of Southwest City. Maximum wind speeds were estimated between 150 and 160 mph. The maximum width of the path was estimated at a quarter of a mile wide.

This tornado destroyed six mobile homes, injuring twelve people, and rolled several vehicles. A number of large trees were snapped or uprooted and a barn was destroyed by the tornado. Maximum estimated wind in the tornado based on this damage was about 125 mph.

Severe thunderstorms developed during the evening of the April 2nd near a stationary frontal boundary that extended across northeastern Oklahoma and southeastern Kansas. A very unstable air mass over the region coupled with strong vertical wind shear resulted in some supercell thunderstorm structures. The storms produced hail up to golfball size, wind gusts of up to 80 mph, and a damaging tornado.

In Craig County, the tornado first damaged barns and trees at the S 440 Road. It moved east-southeast snapping or uprooting trees and damaging barns and outbuildings along the E 200 Road, the S 440 Road, and the E 230 Road before crossing U.S. Interstate Highway I-44, where it blew over two tractor trailers, injuring the driver of one of them. Based on this damage, maximum estimated wind in this segment of the tornado was 95 to 105 mph. The tornado continued into Ottawa County, Oklahoma.

In Ottawa County, the tornado moved through open country and then crossed Highway 60 where it threw several round hay bales. It destroyed barns and outbuildings, damaged several homes, and snapped or uprooted numerous trees as it crossed the S 510 Road and S 520 Road. Based on this damage, maximum estimated wind in this segment of the tornado was 95 to 105 mph.

The tornado crossed into Delaware County near the S 520 Road. Trees were snapped or uprooted, barns and outbuildings were damaged, and homes were damaged as it approached the north end of Grand Lake from the west-northwest. It destroyed a private boat dock on the lake then moved through a community of houses to the east of the lake, resulting in damage to the roofs of homes as well as tree damage. The tornado dissipated to the east of this community in open country. Based on this damage, estimated maximum wind in this segment of the tornado was 95 to 105 mph.

Thunderstorms developed during the evening hours of the November 30, 2018 across central and eastern Oklahoma. Moderately strong atmospheric instability across the area combined with very strong wind shear to produce organized severe thunderstorms, including supercells. Supercell thunderstorms produced several tornadoes and damaging thunderstorm wind gusts across eastern Oklahoma. One of the tornadoes was strong and exceptionally long-tracked, affecting Sequoyah, Cherokee, Adair, and Delaware Counties. A squall line moved rapidly across the area ahead of the surging cold front and produced additional tornadoes and damaging wind gusts.

This long-track tornado developed near Blackgum in Sequoyah where homes were damaged, barns and outbuildings were destroyed, and trees were snapped. The tornado moved north-northeast, snapping and uprooting numerous trees as it approached an inlet of Lake Tenkiller. Based on this damage, maximum estimated wind in this segment of the tornado was 100 to 110 mph.

The tornado moved into Cherokee County near an inlet of Lake Tenkiller, where boat docks, lake homes, boats, and outbuildings were destroyed, and trees and power poles were snapped. The tornado moved north-northeast along the eastern shores of Lake Tenkiller, passing through Cookson and Cherokee Landing State Park. Numerous homes were damaged or destroyed, numerous boat docks were destroyed, many boats were destroyed, outbuildings were destroyed, many trees and power poles were snapped, and hangars at the airport west of Cookson were destroyed. From Lake Tenkiller, the tornado continued to move north-northeast across less populated areas of southeastern Cherokee County where a few homes were damaged, outbuildings were destroyed, and trees were snapped or uprooted. The tornado moved into Adair County to the east-northeast of Welling. Based on this damage, maximum estimated wind in this segment of the tornado was 115 to 125 mph.

The tornado moved into Adair County southwest of Wauhillau and moved north-northeast across OK State Highway 51 and the E768 Road. A couple homes were damaged, outbuildings were damaged, and trees were uprooted. The tornado moved back into Cherokee County northwest of Wauhillau. Based on this damage, maximum estimated wind in this segment of the tornado was 90 to 100 mph.

In Cherokee County, the tornado uprooted trees, and then moved back into Adair County south-southwest of Proctor. Based on this damage, maximum estimated wind in this segment of the tornado was 90 to 100 mph.

This long-track tornado moved back into Adair County south-southwest of Proctor and moved north-northeast snapping and uprooting trees on the 754 Road. The tornado crossed U.S. Highway 62 near Proctor where homes were severely damaged, large outbuildings were destroyed, farm equipment was thrown large distances, and many trees were snapped and uprooted. It snapped and uprooted numerous trees and destroyed barns between U.S. Highway 62 and Chewey Road. Some of the tree damage in this heavily-wooded, rural area was extensive. The tornado continued to move north-northeast across heavily wooded terrain and then crossed River Road where numerous trees were uprooted, and finally into Delaware County near Dripping Springs. Based on this damage, maximum estimated wind in this segment of the tornado was 110 to 120 mph.

The tornado moved into Delaware County southwest of Dripping Springs and Natural Falls State Park, where trees were uprooted. The tornado tracked north-northeast damaging a few homes, destroying a couple outbuildings, and snapping and uprooting trees as it crossed OK State Highway 412. It dissipated southeast of Colcord. Based on this damage, maximum estimated wind in this segment of the tornado was 95 to 105 mph.

A strong, upper-level storm system moved into the Southern Plains from the Rockies on May 20th and 21st. The attendant warm front moved from northern Texas northward into northeastern Oklahoma during the day on May 20th, and then the cold front associated with this storm system moved through eastern Oklahoma during the late evening of May 20th and early morning hours of May 21st. Warm, moist, and very unstable air resided across eastern Oklahoma ahead of this system. This pattern resulted in multiple rounds of severe thunderstorms across eastern Oklahoma from the early afternoon of May 20th through late morning of May 21st. Very strong wind shear coexisting with the strong instability resulted in some supercell thunderstorms that produced large hail up to golfball size and multiple tornadoes on May 20th. A squall line developed along the cold front that moved into the area during the morning of May 21st, and that line of storms produced multiple tornadoes along the leading edge. Locally heavy rainfall and subsequent flash flooding occurred across northeastern Oklahoma as multiple rounds of thunderstorms affected generally the same area.

This large tornado developed southwest of the intersection of the N 420 Road and the W 660 Road. It moved northeast snapping and uprooting trees, and destroying outbuildings when it crossed those roads. Significant tree damage occurred as the tornado crossed the W 650 Road and approached OK State Highway 82, where homes and businesses were severely damaged and numerous trees were snapped in Peggs. After moving through Peggs, the tornado continued to move northeast across mainly rural, rugged terrain where significant tree damage was noted for several miles. It crossed the N 495 Road snapping trees, damaging homes, and destroying outbuildings, and then moved into Delaware County. Based on this damage, maximum estimated wind in this segment of the tornado was 110 to 120 mph.

The tornado moved into the far southwestern portion of Delaware County and moved northeast toward Leach. It damaged homes, destroyed outbuildings, and snapped or uprooted many trees. The tornado crossed the Cherokee Turnpike west of Twin Oaks and dissipated. Based on this damage, maximum estimated wind in this segment of the tornado was 110 to 120 mph.