Thunderstorms developed into eastern Oklahoma during the morning of the 15th. The strongest storms produced damaging wind and a tornado across northeastern Oklahoma. Very moist air across the region, combined with slow storm motion, resulted in locally heavy rainfall and flash flooding. The storms developed slowly southward during the day, with intensification noted as they moved into southeastern Oklahoma, which had become quite unstable by early afternoon. Damaging wind occurred with strongest storms.
A wake low developed on the north side of the southward developing thunderstorm complex during the mid afternoon. A strong pressure gradient associated with this feature resulted in strong, gusty wind developing across portions of northeastern Oklahoma. Wind gusts to near 60 mph, along with some minor damage, occurred locally.
Widespread heavy rainfall of two to four inches across eastern Oklahoma, with amounts as high as six inches, resulted in river flooding. The Poteau River near Panama rose ten feet in just five hours, while the Verdigris River near Lenapah rose fourteen feet in fourteen hours. Moderate river flooding occurred along the Verdigris River near Lenapah, along the Neosho River near Commerce, and along the Poteau River near Panama.

Flash Flood in WAGONER, OKLAHOMA
From 15-MAY-20 10:28:00 to 15-MAY-20 13:00:00 (CST-6)
Location: ONETA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Portions of E 81st Street S were flooded.

Flash Flood in MCINTOSH, OKLAHOMA
From 15-MAY-20 10:30:00 to 15-MAY-20 14:00:00 (CST-6)
Location: CHECOTAH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Roads were flooded in and around Checotah.

Flash Flood in CHEROKEE, OKLAHOMA
From 15-MAY-20 10:39:00 to 15-MAY-20 13:00:00 (CST-6)
Location: MELVIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Portions of Highway 80 southwest of Hulbert were closed due to flooding.

Flash Flood in OKMULGEE, OKLAHOMA
From 15-MAY-20 10:57:00 to 15-MAY-20 14:00:00 (CST-6)
Location: OKMULGEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Roads were flooded in and around Okmulgee.

Flash Flood in WAGONER, OKLAHOMA
From 15-MAY-20 11:13:00 to 15-MAY-20 11:45:00 (CST-6)
Location: GIBSON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread flooding occurred across much of Wagoner County.

Flash Flood in MUSKOGEE, OKLAHOMA
From 15-MAY-20 11:18:00 to 15-MAY-20 14:00:00 (CST-6)
Location: WARNER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Multiple streets were flooded and closed in Warner.

Flash Flood in SEQUOYAH, OKLAHOMA
From 15-MAY-20 11:30:00 to 15-MAY-20 14:15:00 (CST-6)
Location: SALLISAW
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Multiple roads were flooded on the west side of town, with one vehicle stranded in high water.

Flash Flood in MUSKOGEE, OKLAHOMA
From 15-MAY-20 11:48:00 to 15-MAY-20 14:00:00 (CST-6)
Location: SHOPTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Portions of East Hancock Street in Muskogee were flooded and closed.

Flash Flood in SEQUOYAH, OKLAHOMA
From 15-MAY-20 11:58:00 to 15-MAY-20 14:15:00 (CST-6)
Location: SALLISAW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Multiple roads were flooded in and around Sallisaw.

Thunderstorm Wind in MCINTOSH, OKLAHOMA
From 15-MAY-20 09:59:00 to 15-MAY-20 09:59:00 (CST-6)
Location: CHECOTAH
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Strong thunderstorm wind blew down a tree onto a road in Checotah.

Flash Flood in MCINTOSH, OKLAHOMA
From 15-MAY-20 12:18:00 to 15-MAY-20 14:00:00 (CST-6)
Location: EUFAULA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Portions of Birkes Road were flooded on the north side of town.

Flash Flood in LE FLORE, OKLAHOMA
From 15-MAY-20 12:34:00 to 15-MAY-20 16:15:00 (CST-6)
Location: COWLINGTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Portions of Highway 59 near Cowlington were flooded.

Flash Flood in PITTSBURG, OKLAHOMA
From 15-MAY-20 12:34:00 to 15-MAY-20 16:45:00 (CST-6)
Location: MC ALESTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Multiple roads were flooded and closed in and around McAlester.

Thunderstorm Wind in LE FLORE, OKLAHOMA
From 15-MAY-20 12:46:00 to 15-MAY-20 12:46:00 (CST-6)
Location: COWLINGTON
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Strong thunderstorm wind blew roofs off of barns, blew down power lines, and blew down a large electrical tower.

Thunderstorm Wind in LE FLORE, OKLAHOMA
From 15-MAY-20 12:46:00 to 15-MAY-20 12:46:00 (CST-6)
Location: PANAMA
Magnitude: 56.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Strong thunderstorm wind blew a portion of the roof off a house.

Flood in HASKELL, OKLAHOMA
From 15-MAY-20 15:17:00 to 15-MAY-20 23:15:00 (CST-6)
Location: STIGLER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Portions of Highway 82 were flooded and closed, south of the Highway 9 intersection.

Flood in HASKELL, OKLAHOMA
From 15-MAY-20 15:17:00 to 15-MAY-20 23:15:00 (CST-6)
Location: ENTERPRISE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Portions of Highway 71 were flooded and closed, south of the Highway 9 intersection.

High Wind in MUSKOGEE, OKLAHOMA
From 15-MAY-20 15:05:00 to 15-MAY-20 15:05:00 (CST-6)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Oklahoma Mesonet station near Haskell measured 58 mph non-thunderstorm wind gusts.

Flood in NOWATA, OKLAHOMA
From 15-MAY-20 13:15:00 to 17-MAY-20 23:30:00 (CST-6)
Location: SOUTH COFFEYVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The Verdigris River near Lenapah rose above its flood stage of 30 feet at 2:15 pm CDT on May 15th. The river crested at 32.86 feet at 9:00 pm CDT on the 16th, resulting in moderate flooding. Agricultural land along the river was flooded from near the Kansas state line to the headwaters of Lake Oologah. Highway 10 was impassable east of Lenapah. The river fell below flood stage at 12:30 am CDT on the 18th.

Tornado in MUSKOGEE, OKLAHOMA
From 15-MAY-20 08:38:00 to 15-MAY-20 08:49:00 (CST-6)
Location: KEEFETON
Tornado F-scale: EF1
Property damage: 350.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado developed along Elm Grove Road, west of S 25th Street E, where outbuildings were damaged, and trees were uprooted. It moved eastward damaging or destroying about sixteen homes, destroying a number of outbuildings, uprooting numerous trees, and snapping numerous power poles until it dissipated just east of the Muskogee Turnpike. Based on this damage, maximum estimated wind in the tornado was 100 to 110 mph.

Flood in OTTAWA, OKLAHOMA
From 15-MAY-20 10:30:00 to 18-MAY-20 14:45:00 (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 11:30 am CDT on May 15th. The river crested at 19.84 feet at 12:45 pm CDT on the 17th, 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 3:45 pm CDT on the 18th.

Flood in LE FLORE, OKLAHOMA
From 15-MAY-20 21:15:00 to 18-MAY-20 23:00:00 (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 10:15 pm CDT on May 15th. The river crested at 33.83 feet at 7:30 pm CDT on the 16th, resulting in moderate flooding. Agricultural lands and rural roads were flooded. The river fell below flood stage at midnight of the 19th.

Thunderstorm Wind in MUSKOGEE, OKLAHOMA
From 15-MAY-20 08:17:00 to 15-MAY-20 08:17:00 (CST-6)
Location: WAINWRIGHT
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Strong thunderstorm wind damaged the roofs of homes, damaged a barn, and snapped large tree limbs.

Flash Flood in MUSKOGEE, OKLAHOMA
From 15-MAY-20 09:25:00 to 15-MAY-20 11:45:00 (CST-6)
Location: SHOPTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Roads were flooded in and around the Grandview neighborhood on the south side of Muskogee.

High Wind in CHEROKEE, OKLAHOMA
From 15-MAY-20 12:50:00 to 15-MAY-20 12:50:00 (CST-6)
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

High wind blew down several trees, one of which fell onto a house in Tahlequah.

Thunderstorm Wind in MUSKOGEE, OKLAHOMA
From 15-MAY-20 09:30:00 to 15-MAY-20 09:30:00 (CST-6)
Location: WEBBERS FALLS SHEFFI
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Oklahoma Mesonet station south of Webbers Falls measured 59 mph thunderstorm wind gusts.

Flash Flood in WAGONER, OKLAHOMA
From 15-MAY-20 10:10:00 to 15-MAY-20 12:30:00 (CST-6)
Location: ONETA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Portions of Oneta Road were flooded near E 55th Street S.