A very moist and very unstable air mass developed across eastern Oklahoma on the afternoon and evening of the 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.

Hail in CRAIG, OKLAHOMA
From 22-MAY-11 17:07:00 to 22-MAY-11 17:07:00 (CST-6)
Location: VINITA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in OTTAWA, OKLAHOMA
From 22-MAY-11 17:18:00 to 22-MAY-11 17:18:00 (CST-6)
Location: PEORIA
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in WAGONER, OKLAHOMA
From 22-MAY-11 17:22:00 to 22-MAY-11 17:22:00 (CST-6)
Location: NEODESHA
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MUSKOGEE, OKLAHOMA
From 22-MAY-11 19:23:00 to 22-MAY-11 19:23:00 (CST-6)
Location: MUSKOGEE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in PITTSBURG, OKLAHOMA
From 22-MAY-11 20:12:00 to 22-MAY-11 20:12:00 (CST-6)
Location: MC ALESTER
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in TULSA, OKLAHOMA
From 22-MAY-11 21:32:00 to 22-MAY-11 21:32:00 (CST-6)
Location: TULSA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in TULSA, OKLAHOMA
From 22-MAY-11 21:35:00 to 22-MAY-11 21:35:00 (CST-6)
Location: ALSUMA
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in TULSA, OKLAHOMA
From 22-MAY-11 21:45:00 to 22-MAY-11 21:45:00 (CST-6)
Location: ALSUMA
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ROGERS, OKLAHOMA
From 22-MAY-11 22:53:00 to 22-MAY-11 22:53:00 (CST-6)
Location: VERDIGRIS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 19:19:00 to 22-MAY-11 19:27:00 (CST-6)
Location: FLINT
Tornado F-scale: EF2
Property damage: 250.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This is the second of two segments of this tornado. In Delaware County, this tornado severely damaged several homes in the Fiddler's Bend area and snapped or uprooted many trees. Maximum estimated wind in the tornado based on this damage was about 115 mph. Several citizens witnessed this tornado.

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 17:33:00 to 22-MAY-11 17:48:00 (CST-6)
Location: CLEORA
Tornado F-scale: EF2
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado severely damaged several permanent homes, destroyed boat docks, damaged a number of other permanent homes, destroyed at least seven mobile homes, and snapped or uprooted many large trees. Maximum estimated wind in the tornado based on this damage was about 130 mph.
The tornado developed south of Cleora and moved almost due east over land. It then moved across a portion of Grand Lake and back over land north of Dennis, where it appeared to move sharply to the southeast across the northern portion of a peninsula. It likely then moved back over Grand Lake where it dissipated. Storm chasers, storm spotters, and a number of citizens witnessed this tornado.

Tornado in WAGONER, OKLAHOMA
From 22-MAY-11 17:42:00 to 22-MAY-11 17:48:00 (CST-6)
Location: NEODESHA
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado snapped or uprooted a number of large trees. Maximum estimated wind in the tornado based on this damage was about 105 mph.

Hail in OKMULGEE, OKLAHOMA
From 22-MAY-11 18:48:00 to 22-MAY-11 18:48:00 (CST-6)
Location: COALTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tornado in CHEROKEE, OKLAHOMA
From 22-MAY-11 18:50:00 to 22-MAY-11 18:50:00 (CST-6)
Location: SCRAPER
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A brief tornado witnessed by storm chasers developed over open country. No known damage occurred as a result of the tornado.

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 19:29:00 to 22-MAY-11 19:30:00 (CST-6)
Location: TWIN OAKS
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser witnessed a brief tornado over open country. No known damage occurred as a result of this tornado.

Tornado in ADAIR, OKLAHOMA
From 22-MAY-11 19:14:00 to 22-MAY-11 19:19:00 (CST-6)
Location: CHEWEY
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This is the first of two segments of this tornado. In Adair County, this tornado uprooted large trees and snapped large tree limbs. Maximum estimated wind in the tornado based on this damage was about 95 mph. The tornado continued into Delaware County.

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 19:30:00 to 22-MAY-11 19:37:00 (CST-6)
Location: MOSELEY
Tornado F-scale: EF2
Property damage: 400.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A 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.

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 19:36:00 to 22-MAY-11 19:40:00 (CST-6)
Location: MOSELEY
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado snapped or uprooted a number of large trees. Maximum estimated wind in the tornado based on this damage was about 105 mph.

Hail in OTTAWA, OKLAHOMA
From 22-MAY-11 16:27:00 to 22-MAY-11 16:27:00 (CST-6)
Location: PICHER
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in OKFUSKEE, OKLAHOMA
From 22-MAY-11 18:00:00 to 22-MAY-11 18:00:00 (CST-6)
Location: WELEETKA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in OKMULGEE, OKLAHOMA
From 22-MAY-11 18:07:00 to 22-MAY-11 18:07:00 (CST-6)
Location: HENRYETTA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CHEROKEE, OKLAHOMA
From 22-MAY-11 18:10:00 to 22-MAY-11 18:10:00 (CST-6)
Location: PEGGS
Magnitude: 4.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in CHEROKEE, OKLAHOMA
From 22-MAY-11 18:39:00 to 22-MAY-11 18:39:00 (CST-6)
Location: MOODYS
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 17:52:00 to 22-MAY-11 18:26:00 (CST-6)
Location: DENNIS
Tornado F-scale: EF3
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

This is the first of two segments of this tornado. The tornado developed about 2.5 miles west-southwest of Zena, moved east-northeast across Grand Lake and then south of Zena crossing Highway 59 just north of the intersection with 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 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.

Thunderstorm Wind in OKFUSKEE, OKLAHOMA
From 22-MAY-11 18:00:00 to 22-MAY-11 18:00:00 (CST-6)
Location: WELEETKA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several trees were uprooted by strong thunderstorm winds.

Tornado in CHEROKEE, OKLAHOMA
From 22-MAY-11 18:27:00 to 22-MAY-11 18:35:00 (CST-6)
Location: PEGGS
Tornado F-scale: EF1
Property damage: 70.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado destroyed a mobile home, damaged the roof of a permanent home, and snapped or uprooted large trees. Maximum estimated wind in the tornado based on this damage was about 110 mph.

Hail in CHEROKEE, OKLAHOMA
From 22-MAY-11 18:42:00 to 22-MAY-11 18:42:00 (CST-6)
Location: PEGGS
Magnitude: 2.75 
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in MUSKOGEE, OKLAHOMA
From 22-MAY-11 18:56:00 to 22-MAY-11 18:56:00 (CST-6)
Location: MUSKOGEE DAVIS ARPT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS at the Muskogee Davis Airport measured 60 mph thunderstorm wind gusts.

Hail in CHEROKEE, OKLAHOMA
From 22-MAY-11 19:27:00 to 22-MAY-11 19:27:00 (CST-6)
Location: PEGGS
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MAYES, OKLAHOMA
From 22-MAY-11 19:42:00 to 22-MAY-11 19:42:00 (CST-6)
Location: LOCUST GROVE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

An amateur radio operator estimated 60 mph thunderstorm wind gusts.

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 19:44:00 to 22-MAY-11 19:45:00 (CST-6)
Location: WEST SILOAM SPGS
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado snapped or uprooted large trees. Maximum estimated wind in the tornado based on this damage was about 100 mph.

Thunderstorm Wind in LE FLORE, OKLAHOMA
From 22-MAY-11 20:52:00 to 22-MAY-11 20:52:00 (CST-6)
Location: SUMMERFIELD
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management personnel estimated 70 mph thunderstorm wind gusts. Large tree limbs were blown down.

Hail in ROGERS, OKLAHOMA
From 22-MAY-11 21:45:00 to 22-MAY-11 21:45:00 (CST-6)
Location: CATOOSA
Magnitude: 2.00 
Property damage: 15.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in TULSA, OKLAHOMA
From 22-MAY-11 21:46:00 to 22-MAY-11 21:46:00 (CST-6)
Location: GARNETT
Magnitude: 2.00 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in LE FLORE, OKLAHOMA
From 22-MAY-11 21:55:00 to 22-MAY-11 21:55:00 (CST-6)
Location: POTEAU
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Strong thunderstorm wind blew down trees and power lines across the county.

Thunderstorm Wind in LE FLORE, OKLAHOMA
From 22-MAY-11 21:58:00 to 22-MAY-11 21:58:00 (CST-6)
Location: CAMERON
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management personnel estimated 70 mph thunderstorm wind gusts with trees and power lines blown down.

Hail in ROGERS, OKLAHOMA
From 22-MAY-11 22:05:00 to 22-MAY-11 22:05:00 (CST-6)
Location: CATOOSA
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in DELAWARE, OKLAHOMA
From 22-MAY-11 19:13:00 to 22-MAY-11 19:25:00 (CST-6)
Location: LEACH
Tornado F-scale: EF1
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado damaged several homes and barns, and snapped or uprooted a number of large trees. Maximum estimated wind in the tornado based on this damage was about 105 mph. Several storm chasers, storm spotters, and citizens witnessed this tornado.