An area of low pressure moved up from the Mississippi River Valley into Ohio. The storm system had adequate moisture from the Gulf of Mexico, which increased rainfall rates to over an inch and a half per hour. This intense rainfall triggered several small rivers and streams to overflow their banks, and for low lying and poor drainage areas to flood. The highest rainfall amounts were observed over northwest OH with 2 to 3 inches reported near Toledo. Amounts this high were observed elsewhere, though they were more spotty and not over the same basins. Widespread 1 to 2 inches was the average rainfall totals across the region.

Flash Flood in GEAUGA, OHIO
From 14-MAY-11 18:38:00 to 14-MAY-11 20:00:00 (EST-5)
Location: PARKMAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Saturated ground cover could not hold any additional rain, however on the evening of the 14th torrential rainfall brought an additional inch to Geauga County. The rain fell within 75 minutes, resulting in rapid runoff. The result was flash flooding mainly over northern portions of the county where rainfall was the heaviest. Several state and local roads were flooded including RT 528 in Parkman.

Flash Flood in ASHTABULA, OHIO
From 14-MAY-11 21:00:00 to 14-MAY-11 23:00:00 (EST-5)
Location: GENEVA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Storms with torrential rainfall combined with saturated ground conditions resulted in flash flooding over Ashtabula County. Several small streams and creeks were already swollen due to recent rains and floods, so the additional inch to an inch and a half was more than sufficient to produce flooding. Several creeks came out of banks, with portions of ST RT 46 closed as several inches of flowing water from a small creek near the town of Rock Creek covered the road.

Flash Flood in CUYAHOGA, OHIO
From 14-MAY-11 16:00:00 to 14-MAY-11 17:00:00 (EST-5)
Location: PARMA HGTS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Torrential rain from passing thunderstorms brought as much as 2.5 or rain to portions of Cuyahoga County. This intense rainfall over saturated grounds produced rapid runoff. The result was several roads flooded, including Smith Road in Middleburg Heights where several inches of flowing water was observed. Portions of Westlake, Parma, and Garfield Heights experienced flooding in non-typical places as well. West 130th St in Cleveland Ohio was impassable due to flash flooding when several feet of flowing water filled the road in 10 minutes.

Flash Flood in ASHLAND, OHIO
From 14-MAY-11 18:00:00 to 14-MAY-11 19:00:00 (EST-5)
Location: ASHLAND
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Newspaper

Strong thunderstorms brought wind, hail, and torrential rain to Ashland County on the evening of the 14th. Doppler Radar estimated as much as 2 inches fell within two hours over northern portions of the county. The result was several roads flooded. Flood damage closed County Road 1302 between U.S. 42 and Township Road 753 in Montgomery Township.

Flash Flood in PORTAGE, OHIO
From 14-MAY-11 19:30:00 to 14-MAY-11 21:00:00 (EST-5)
Location: STREETSBORO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several days of heavy rain set the stage for additional flooding on the 14th. Heavy rain with rates over an inch per hour resulted in flash flooding over portions of Portage County. Several roads had to be closed near Streetsboro including RT 303.

Flood in MAHONING, OHIO
From 14-MAY-11 20:30:00 to 14-MAY-11 22:00:00 (EST-5)
Location: SHIVELY CORNERS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Overwhelmed drainage systems and saturated ground cover from recent floods and heavy rain set the stage for additional flooding on the 14th. A storm brought an inch or less of rainfall to the Youngstown area, however the high rate of rainfall was sufficient to produce flooding. Several roads in Youngstown flooded with up to a foot of water as drains backed up.

Flash Flood in TRUMBULL, OHIO
From 14-MAY-11 21:15:00 to 15-MAY-11 00:00:00 (EST-5)
Location: BRACEVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several days of heavy rain had led to saturated ground and swollen creeks and streams across Trumbull County. On the 14th line of thunderstorms brought an additional inch to an inch and a half of rainfall. This rainfall became almost enirely runoff, which rapidly flooded low lying and poor drainage areas. A car became stuck on the road on RT 40 near Leavittsburg, where water was also entering apartment buildings. Several roads had to be closed.

Flash Flood in TRUMBULL, OHIO
From 14-MAY-11 22:30:00 to 15-MAY-11 00:00:00 (EST-5)
Location: NORTH BLOOMFIELD
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Torrential rain fell over Trumbull County on the evening of the 14th, this after three preceding days of flooding. The saturated ground could not handle additional rainfall, so the one to two inches that fell on this evenig resulted in flash flooding. Several creeks mainly in northern portions of the county came out of their banks. Basements flooded in the Howland Township area. Several roads were impassable including OH 193.

Flash Flood in HANCOCK, OHIO
From 14-MAY-11 15:30:00 to 14-MAY-11 17:00:00 (EST-5)
Location: NEW STARK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Two seperate severe thunderstorms brought strong winds, hail, and torrential rain to Hancock County. The heaviest rainfall from the first storm fell over Findlay with as much as 1.75 in 75 minutes. The second storm followed shortly behind the first, but this time further south over Arlington. Doppler radar estimates as much as 2.5 fell in this area. The combined rainfall over the Eagle Creek watershed caused it to spill into downtown Arlington. In Arlington several roads were flooded, with two to three feet of water over South Main Street.

Flash Flood in SENECA, OHIO
From 14-MAY-11 17:00:00 to 14-MAY-11 18:30:00 (EST-5)
Location: BASCOM
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A series of strong to severe thunderstorms rolled through Seneca County, with strong winds, hail, and torrential rainfall. The rainfall resulted in flash flooding across the county. Sheriff's department reported water running across several roads with creeks coming out of their banks. Storm drains in the city of Tiffin were overwhelmed which caused water rises up to the hoods of cars downtown. A person had to be rescued as a result. A railroad underpass in Tiffin was flooded several feet deep.

Flash Flood in MARION, OHIO
From 14-MAY-11 16:15:00 to 14-MAY-11 17:00:00 (EST-5)
Location: MEEKER
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Torrential rain fell over portions of Marion County as severe thunderstorms moved through the region. Rainfall rates over an inch per hour produced rapid runoff with rapid filling of small streams and creeks. This resulted in the flooding of local roadways. Rocky Fork, Prairie Run, and Grave Creek came over their banks, some  by as much as 2.5 feet. The Marion County Engineers office says numerous county gravel roads were flooded and closed.

Flash Flood in LORAIN, OHIO
From 14-MAY-11 18:35:00 to 14-MAY-11 21:30:00 (EST-5)
Location: LORAIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Lorain County experienced their third straight day of flooding on the 14th. Storms brought around an inch of additional rainfall, but this in addition to already swollen streams and saturated ground cover was enough to trigger additional flooding. Several creeks came out of their banks and water was running across several roads. The speed that the water rose caught motorists by surprise as many cars stalled in high water.