Elevated severe thunderstorms containing large hail developed north of a warm front that was moving slowly northward across eastern Oklahoma and west central Arkansas during the morning and early afternoon of the 10th.
Another round of severe thunderstorms developed late in the afternoon as a dry line approached the area from the west. Extreme instability and strong vertical wind shear resulted in the development of long-lived supercell thunderstorms that moved across eastern Oklahoma and northwestern Arkansas during the late afternoon and evening. Several of these supercells became tornadic and a few produced long-lived damaging tornadoes.
One such supercell developed and moved along the Oklahoma-Kansas border and then into southwestern Missouri. This storm produced a tornado in northeastern Craig County OK that remained on the ground for 29 miles in Oklahoma, continued for about 31 miles in Newton County MO, and finally dissipated about 15 miles into Barry County MO. It produced EF-4 damage in several locations, including Picher, a small town in north-central Ottawa County OK. Twenty-one fatalities, over 350 injuries, and an estimated $60 million in property damage resulted from this tornado in Oklahoma and Missouri. Six of the fatalities and about 150 injuries occurred in Picher OK.
Other strong tornadoes developed and moved across portions of Pittsburg and Latimer Counties. A EF-2 tornado was on the ground for about eight miles west of McAlester, damaging numerous homes in its path. Another EF-2 tornado developed southwest of Hartshorne in Pittsburg County and moved 19 miles before dissipating just east of Yanush in Latimer County. Four injuries resulted from that tornado and numerous homes were severely damaged or destroyed.

Tornado in PITTSBURG, OKLAHOMA
From 10-MAY-08 16:42:00 to 10-MAY-08 16:55:00 (CST-6)
Location: HARTSHORNE
Tornado F-scale: EF2
Property damage: 200.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado destroyed mobile homes, severely damaged permanent homes, snapped or uprooted numerous trees, destroyed barns and outbuildings, and blew down power poles and power lines. This tornado continued into Latimer County.

Hail in MCINTOSH, OKLAHOMA
From 10-MAY-08 12:28:00 to 10-MAY-08 12:28:00 (CST-6)
Location: STIDHAM
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in SEQUOYAH, OKLAHOMA
From 10-MAY-08 13:28:00 to 10-MAY-08 13:28:00 (CST-6)
Location: VIAN
Magnitude: 1.50 
Reported by: Amateur Radio

Hail in LE FLORE, OKLAHOMA
From 10-MAY-08 14:14:00 to 10-MAY-08 14:14:00 (CST-6)
Location: POTEAU
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in SEQUOYAH, OKLAHOMA
From 10-MAY-08 13:35:00 to 10-MAY-08 13:35:00 (CST-6)
Location: MARBLE CITY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm Wind in ROGERS, OKLAHOMA
From 10-MAY-08 15:51:00 to 10-MAY-08 15:51:00 (CST-6)
Location: CLAREMORE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds estimated at 70 miles an hour blew down several large trees on the east side of Claremore.

Hail in SEQUOYAH, OKLAHOMA
From 10-MAY-08 13:40:00 to 10-MAY-08 13:40:00 (CST-6)
Location: SALLISAW
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Tornado in PUSHMATAHA, OKLAHOMA
From 10-MAY-08 17:30:00 to 10-MAY-08 17:32:00 (CST-6)
Location: SNOW
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

An NWS storm survey determined that a tornado snapped or uprooted numerous trees north of town.

Tornado in OTTAWA, OKLAHOMA
From 10-MAY-08 16:48:00 to 10-MAY-08 16:50:00 (CST-6)
Location: QUAPAW
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado developed from the Picher supercell and moved east-southeast eventually merging with the then decaying Picher tornado. The merger apparently reintensified the original tornadic circulation as it quickly became a mile-wide just north of Peoria. A NWS storm survey found extensive tree damage associated with this second tornado prior to its aforementioned merger with the original tornado.

Hail in HASKELL, OKLAHOMA
From 10-MAY-08 13:56:00 to 10-MAY-08 13:56:00 (CST-6)
Location: KINTA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Tornado in PITTSBURG, OKLAHOMA
From 10-MAY-08 16:03:00 to 10-MAY-08 16:21:00 (CST-6)
Location: HAYWOOD
Tornado F-scale: EF2
Property damage: 500.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A strong tornado severely damaged homes, snapped and uprooted numerous trees, and blew down power poles and power lines.

Tornado in PITTSBURG, OKLAHOMA
From 10-MAY-08 16:21:00 to 10-MAY-08 16:21:00 (CST-6)
Location: CROWDER
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado formed and dissipated over Lake Eufaula. Several people witnessed this tornado including storm chasers affiliated with Tulsa television stations and fishermen on the lake.

Hail in HASKELL, OKLAHOMA
From 10-MAY-08 13:35:00 to 10-MAY-08 13:35:00 (CST-6)
Location: STIGLER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in LE FLORE, OKLAHOMA
From 10-MAY-08 13:58:00 to 10-MAY-08 13:58:00 (CST-6)
Location: COWLINGTON
Magnitude: 1.50 
Reported by: Amateur Radio

Hail in MAYES, OKLAHOMA
From 10-MAY-08 10:58:00 to 10-MAY-08 10:58:00 (CST-6)
Location: LOCUST GROVE
Magnitude: 1.75 
Property damage: 25.00K
Reported by: Emergency Manager

Tornado in LATIMER, OKLAHOMA
From 10-MAY-08 16:34:00 to 10-MAY-08 16:44:00 (CST-6)
Location: WILBURTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser filmed a tornado northwest of town. It occurred in a remote area of the county, and thus a ground survey could not be conducted.

Tornado in PUSHMATAHA, OKLAHOMA
From 10-MAY-08 17:10:00 to 10-MAY-08 17:14:00 (CST-6)
Location: ADEL
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado developed northeast of Daisy in Atoka County and moved into northwestern Pushmataha County, uprooting and snapping numerous trees.

Hail in CHEROKEE, OKLAHOMA
From 10-MAY-08 11:15:00 to 10-MAY-08 11:15:00 (CST-6)
Location: TAHLEQUAH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in MCINTOSH, OKLAHOMA
From 10-MAY-08 12:35:00 to 10-MAY-08 12:35:00 (CST-6)
Location: ONAPA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Tornado in MCINTOSH, OKLAHOMA
From 10-MAY-08 16:19:00 to 10-MAY-08 16:19:00 (CST-6)
Location: CHECOTAH
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tornado, witnessed by several trained storm spotters, touched down briefly in open country.

Hail in MCINTOSH, OKLAHOMA
From 10-MAY-08 13:00:00 to 10-MAY-08 13:00:00 (CST-6)
Location: CHECOTAH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tornado in PITTSBURG, OKLAHOMA
From 10-MAY-08 16:25:00 to 10-MAY-08 16:27:00 (CST-6)
Location: MC ALESTER
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A tornado damaged trees just southwest of town. It was filmed by a helicopter crew from KFOR-TV in Oklahoma City and was witnessed by the public.

Hail in ADAIR, OKLAHOMA
From 10-MAY-08 11:45:00 to 10-MAY-08 11:45:00 (CST-6)
Location: WESTVILLE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tornado in MAYES, OKLAHOMA
From 10-MAY-08 16:25:00 to 10-MAY-08 16:25:00 (CST-6)
Location: PRYOR
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A brief tornado produced minor tree damage northeast of town.

Hail in PITTSBURG, OKLAHOMA
From 10-MAY-08 16:04:00 to 10-MAY-08 16:04:00 (CST-6)
Location: INDIANOLA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in PITTSBURG, OKLAHOMA
From 10-MAY-08 16:36:00 to 10-MAY-08 16:36:00 (CST-6)
Location: QUINTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in OTTAWA, OKLAHOMA
From 10-MAY-08 16:25:00 to 10-MAY-08 16:54:00 (CST-6)
Location: NORTH MIAMI
Tornado F-scale: EF4
Property damage: 15.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado developed at 1620 cst in northeastern Craig County and continued into Ottawa County. The tornado moved rapidly eastward toward the town of Picher where it destroyed about 200 homes, killed six people, and injured another 150 people at about 540 pm. Damage in and around Picher was rated EF-4 on the Enhanced Fujita Scale.
The tornado began moving more southeasterly near Picher and struck the north side of Quapaw. While this tornado was beginning to weaken east of Quapaw, the supercell produced another tornado a few miles east-northeast of Quapaw that merged with this tornado just east of I-44. After the merger of the two tornadoes, a single tornadic circulation reintensified and became about a mile wide for several miles before moving into Newton County MO.

Hail in MUSKOGEE, OKLAHOMA
From 10-MAY-08 16:10:00 to 10-MAY-08 16:10:00 (CST-6)
Location: KEEFETON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in CRAIG, OKLAHOMA
From 10-MAY-08 16:20:00 to 10-MAY-08 16:25:00 (CST-6)
Location: WELCH
Tornado F-scale: EF2
Property damage: 600.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado developed just south of the Oklahoma-Kansas border north-northwest of Welch. It moved rapidly east across northeastern Craig County, intensifying and widening as it moved into Ottawa County. In Craig County, the tornado destroyed several mobile homes, severely damaged about a dozen other homes, snapped or uprooted numerous trees, and blew down power poles and power lines.

Hail in PUSHMATAHA, OKLAHOMA
From 10-MAY-08 17:42:00 to 10-MAY-08 17:42:00 (CST-6)
Location: NASHOBA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Post Office

Tornado in PUSHMATAHA, OKLAHOMA
From 10-MAY-08 17:35:00 to 10-MAY-08 17:35:00 (CST-6)
Location: ALBION
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado snapped or uprooted several trees along Indian Highway.

Hail in LE FLORE, OKLAHOMA
From 10-MAY-08 17:59:00 to 10-MAY-08 17:59:00 (CST-6)
Location: OCTAVIA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WAGONER, OKLAHOMA
From 10-MAY-08 10:50:00 to 10-MAY-08 10:50:00 (CST-6)
Location: OKAY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAIR, OKLAHOMA
From 10-MAY-08 17:02:00 to 10-MAY-08 17:02:00 (CST-6)
Location: WESTVILLE
Magnitude: 1.50 
Reported by: Emergency Manager

Hail in SEQUOYAH, OKLAHOMA
From 10-MAY-08 17:04:00 to 10-MAY-08 17:04:00 (CST-6)
Location: MARBLE CITY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in SEQUOYAH, OKLAHOMA
From 10-MAY-08 16:50:00 to 10-MAY-08 16:50:00 (CST-6)
Location: VIAN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in ADAIR, OKLAHOMA
From 10-MAY-08 16:50:00 to 10-MAY-08 16:50:00 (CST-6)
Location: PROCTOR
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds estimated at 70 miles an hour blew several trees down onto a county road just south of Proctor.

Hail in LATIMER, OKLAHOMA
From 10-MAY-08 16:47:00 to 10-MAY-08 16:47:00 (CST-6)
Location: WILBURTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ADAIR, OKLAHOMA
From 10-MAY-08 16:57:00 to 10-MAY-08 16:57:00 (CST-6)
Location: CHRISTIE
Magnitude: 2.75 
Property damage: 20.00K
Reported by: Public

Hail in MAYES, OKLAHOMA
From 10-MAY-08 16:39:00 to 10-MAY-08 16:39:00 (CST-6)
Location: SPAVINAW
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in CHEROKEE, OKLAHOMA
From 10-MAY-08 16:47:00 to 10-MAY-08 16:47:00 (CST-6)
Location: ELDON
Magnitude: 1.75 
Property damage: 20.00K
Reported by: Public

Hail in MAYES, OKLAHOMA
From 10-MAY-08 16:12:00 to 10-MAY-08 16:12:00 (CST-6)
Location: PRYOR
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HASKELL, OKLAHOMA
From 10-MAY-08 16:47:00 to 10-MAY-08 16:47:00 (CST-6)
Location: KINTA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in LATIMER, OKLAHOMA
From 10-MAY-08 16:55:00 to 10-MAY-08 17:15:00 (CST-6)
Location: HIGGINS
Tornado F-scale: EF2
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado continued from Pittsburg County. As it moved into Latimer County, the tornado destroyed a double-wide mobile home, severely damaged another home and barn, and rolled an F350 pickup truck about 50 yards. Numerous trees were snapped or uprooted as the tornado approached Yanush. In Yanush, about 50 homes were damaged, eight of those were destroyed along with one business. Numerous sheds, barns, and outbuildings were destroyed. Numerous trees and power lines were blown down.

Thunderstorm Wind in ADAIR, OKLAHOMA
From 10-MAY-08 16:50:00 to 10-MAY-08 16:50:00 (CST-6)
Location: PROCTOR
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated at 70 miles an hour blew down a few trees.