Thunderstorms developed during the afternoon of the 25th across southeastern Oklahoma, to the north of an upper level disturbance approaching the area from eastern Texas. The atmosphere had become moderately unstable ahead of the thunderstorms, and the low level wind shear had become strong. The combination of instability and wind shear promoted the development of supercell thunderstorms, which formed ahead of a squall line. The supercells produced multiple tornadoes, along with damaging wind.
These thunderstorms also produced widespread two to four inches of rain across much of eastern Oklahoma. This rainfall occurred following several days of rain, which resulted in five-day totals of four to eight inches across portions of eastern Oklahoma. Moderate flooding of the Neosho River near Commerce, and the Poteau River near Panama, resulted from this widespread heavy rain.

Tornado in ADAIR, OKLAHOMA
From 25-MAY-20 18:11:00 to 25-MAY-20 18:13:00 (CST-6)
Location: WATTS
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado uprooted trees and snapped large tree limbs. It was recorded by a tower camera in West Siloam Springs, and was witnessed by several storm chasers. Based on this damage, maximum estimated wind in the tornado was 85 to 90 mph.

Tornado in SEQUOYAH, OKLAHOMA
From 25-MAY-20 16:37:00 to 25-MAY-20 16:38:00 (CST-6)
Location: BLACKGUM
Tornado F-scale: EF0
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado destroyed boat storage units, blew down power poles, and snapped large tree limbs. It was observed by storm chasers. Based on the damage, maximum estimated wind in the tornado was 80 to 85 mph.

Tornado in DELAWARE, OKLAHOMA
From 25-MAY-20 18:34:00 to 25-MAY-20 18:34:00 (CST-6)
Location: ROW
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado snapped large tree limbs, and was observed by storm chasers. Based on this damage, maximum estimated wind in the tornado was 70 to 80 mph.

Tornado in DELAWARE, OKLAHOMA
From 25-MAY-20 18:45:00 to 25-MAY-20 18:46:00 (CST-6)
Location: MAYSVILLE
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado uprooted trees. It likely had a longer path length, but occurred in a heavily-wooded area that was mostly inaccessible by road. Based on this damage, maximum estimated wind in the tornado was 85 to 95 mph.

Tornado in DELAWARE, OKLAHOMA
From 25-MAY-20 19:13:00 to 25-MAY-20 19:19:00 (CST-6)
Location: GROVE ARPT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado snapped large tree limbs as it crossed several county roads. Based on this damage, maximum estimated wind in the tornado was 70 to 80 mph.

Thunderstorm Wind in SEQUOYAH, OKLAHOMA
From 25-MAY-20 17:06:00 to 25-MAY-20 17:08:00 (CST-6)
Location: HANSON
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Strong thunderstorm wind uprooted a couple trees and snapped large tree limbs.

Thunderstorm Wind in SEQUOYAH, OKLAHOMA
From 25-MAY-20 17:09:00 to 25-MAY-20 17:09:00 (CST-6)
Location: HANSON
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Strong thunderstorm wind uprooted trees.

Thunderstorm Wind in SEQUOYAH, OKLAHOMA
From 25-MAY-20 17:16:00 to 25-MAY-20 17:16:00 (CST-6)
Location: SALLISAW
Magnitude: 64.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Strong thunderstorm wind snapped large tree limbs.

Thunderstorm Wind in DELAWARE, OKLAHOMA
From 25-MAY-20 18:21:00 to 25-MAY-20 18:21:00 (CST-6)
Location: MOSELEY
Magnitude: 64.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Strong thunderstorm wind snapped large tree limbs.

Thunderstorm Wind in DELAWARE, OKLAHOMA
From 25-MAY-20 18:37:00 to 25-MAY-20 18:37:00 (CST-6)
Location: COLCORD
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm wind gusts were estimated to 70 mph.

Flood in LE FLORE, OKLAHOMA
From 26-MAY-20 00:45:00 to 29-MAY-20 03:45:00 (CST-6)
Location: SHADY PT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The Poteau River near Panama rose above its flood stage of 29 feet at 1:45 am CDT on May 26th. The river crested at 34.56 feet at 5:45 am CDT on the 27th, resulting in moderate flooding. Agricultural lands and rural roads were flooded. The river fell below flood stage at 4:45 am CDT on the 29th.

Flood in OTTAWA, OKLAHOMA
From 26-MAY-20 09:45:00 to 31-MAY-20 04:30:00 (CST-6)
Location: NORTH MIAMI
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The Neosho River near Commerce rose above its flood stage of 15 feet at 10:45 am CDT on May 26th. The river crested at 19.78 feet at 2:30 pm CDT on the 28th, resulting in moderate flooding. Low lying areas around Miami were flooded, including Riverview Park, and Highway 125 near the Fairgrounds was flooded. The river fell below flood stage at 5:30 am CDT on the 31st.