A stationary frontal boundary was located from the Texas panhandle, into west central and central Oklahoma Oklahoma during the late afternoon hours. Very unstable air was in place along and south of the boundary. Thunderstorms developed over the Texas panhandle and developed eastward along the boundary. The combination of the very unstable air and decent vertical wind shear allowed for some of the thunderstorms to become better organized, with severe weather reported over parts of west central into central Oklahoma. Later in the evening, additional thunderstorms developed north of the boundary as the low-level jet developed. Severe weather was reported over parts of northern Oklahoma, mainly in the form of strong winds and very heavy rainfall.

Thunderstorm Wind in CADDO, OKLAHOMA
From 17-AUG-09 20:30:00 to 17-AUG-09 20:35:00 (CST-6)
Location: HINTON
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A wind gust of 58 mph was measured at 2130 cdt, another gust of 62 mph was measured at 2135 cdt, and another gust to 66 mph was measured at 2140 cdt.

Hail in GRANT, OKLAHOMA
From 17-AUG-09 20:35:00 to 17-AUG-09 20:35:00 (CST-6)
Location: LAMONT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in GRANT, OKLAHOMA
From 17-AUG-09 18:25:00 to 17-AUG-09 18:25:00 (CST-6)
Location: NASH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in KAY, OKLAHOMA
From 17-AUG-09 19:05:00 to 17-AUG-09 19:05:00 (CST-6)
Location: BLACKWELL
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm Wind in CUSTER, OKLAHOMA
From 17-AUG-09 19:05:00 to 17-AUG-09 19:05:00 (CST-6)
Location: BUTLER
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in WASHITA, OKLAHOMA
From 17-AUG-09 19:30:00 to 17-AUG-09 19:30:00 (CST-6)
Location: BESSIE
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in BLAINE, OKLAHOMA
From 17-AUG-09 17:43:00 to 17-AUG-09 17:43:00 (CST-6)
Location: ROMAN NOSE ST PARK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

Flash Flood in GRANT, OKLAHOMA
From 17-AUG-09 19:45:00 to 17-AUG-09 21:45:00 (CST-6)
Location: MEDFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash flooding was reported near the One Oak Plant, two to three miles southwest of Medford on Highway 81. Additional flooding was reported on CR M and M.

Hail in BLAINE, OKLAHOMA
From 17-AUG-09 19:45:00 to 17-AUG-09 19:45:00 (CST-6)
Location: GREENFIELD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in CUSTER, OKLAHOMA
From 17-AUG-09 19:55:00 to 17-AUG-09 19:55:00 (CST-6)
Location: WEATHERFORD
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in CANADIAN, OKLAHOMA
From 17-AUG-09 20:40:00 to 17-AUG-09 20:40:00 (CST-6)
Location: CALUMET
Magnitude: 61.00 EG
Crop damage: 0.00K
Reported by: Amateur Radio

A tractor trailer was blown over on eastbound Highway 281, three miles northwest of Interstate 40, off of exit 108. Significant tree damage was also reported at this location. Monetary damage estimates were not available.

Thunderstorm Wind in CADDO, OKLAHOMA
From 17-AUG-09 20:45:00 to 17-AUG-09 20:47:00 (CST-6)
Location: BRIDGEPORT
Magnitude: 61.00 EG
Crop damage: 0.00K
Reported by: Amateur Radio

A tractor trailer was blown over on Interstate 40 near mile marker 103. Tree damage was also reported at this location. Monetary damage estimates were not available.

Flash Flood in GARFIELD, OKLAHOMA
From 18-AUG-09 00:00:00 to 18-AUG-09 03:30:00 (CST-6)
Location: KREMLIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Highways 45 and 81, north and west of Enid, were closed due to water running over top of them. Several county roads were also closed in these areas due to high water.

Flash Flood in KAY, OKLAHOMA
From 17-AUG-09 22:00:00 to 18-AUG-09 01:00:00 (CST-6)
Location: BLACKWELL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several streets in Blackwell were closed due to water running over top of them. Several county roads west of town were also impassable.

Thunderstorm Wind in KAY, OKLAHOMA
From 17-AUG-09 22:45:00 to 17-AUG-09 22:47:00 (CST-6)
Location: PONCA CITY
Magnitude: 65.00 EG
Property damage: 900.00K
Crop damage: 0.00K
Reported by: County Official

Widespread wind damage was reported over the southeast parts of Ponca City. The damage area was from S. 8th to S. 13th from South Ave north about 4 to 5 blocks. Numerous trees and power lines were blown down. Several houses reported at least minor damage, with one home blown off its foundation and losing its roof. Monetary damage is estimated based on figures from Ponca City Emergency Management.