An anomalously-warm and moist air mass was in place across much of the Central Plains and Midwest, resulting in strong to perhaps extreme instability in addition to tropical-like precipitable water values exceeding 2.0 inches. The Lower Great Lakes region, specifically northern Ohio and Northwest Pennsylvania found itself on the eastern edge of this heat dome. Strong northwest flow aloft persisted along the periphery of the anomalously-warm and moist air mass, allowing for organized storms to develop across northern Ohio and Northwest Pennsylvania. A constant feed of moisture allowed these storms to maintain their intensity throughout the evening and overnight hours of Aug 23, 2023 and into the early morning hours of Aug 24, 2023 as they slowly pivoted southwest. Numerous flash flood warnings were issued with 3 considerable tags utilized throughout the course of the event. The hardest-hit areas were along the lakeshore between Toledo and Cleveland where there were several reports of 5 to 7 inches of rainfall. Elsewhere, generally 2 to 4 inches of rainfall was common, most of which fell in only a few hours. The area was on the edge of an extremely unstable airmass with sufficient deep-layer shear for organized convection.

Flash Flood in CUYAHOGA, OHIO
From 23-AUG-23 20:15:00 to 23-AUG-23 22:40:00 (EST-5)
Location: NORTH OLMSTED
Flood cause: Heavy Rain
Property damage: 750.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Extensive flash flooding in North Olmsted, Brooklyn, Brook Park, Parma, and Parma Heights. Widespread basement flooding and road closures. Several underpasses under I-480 inundated with flood waters. A structure collapse was reported in North Olmsted due to the weight of water on the roof. Flooded roadways include Brookpark Road, West Ridgewood Drive, Pleasant Valley Road near York Road, and Sprague Road near West 130th Street. Multiple water rescues reported in this area. Cleveland Metroparks Zoo experienced flood damage due to flooding of Big Creek. The USGS river gage near the zoo on Big Creek rose from 3.8 feet to 12.8 feet in 70 minutes before the gage was knocked out of service by a fallen tree. Radar estimated 1.5 to 2.25 inches of rainfall in less than three hours, with much of the rainfall falling in less than one hour.

Flash Flood in GEAUGA, OHIO
From 23-AUG-23 20:00:00 to 23-AUG-23 22:30:00 (EST-5)
Location: MULBERRY CORNERS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rainfall caused flash flooding of East Branch Chagrin River in Chardon Township. The river came out of its banks flooding Mitchells Mills Road near Wisner Road.  Radar estimated 1.75 to 2.5 inches of rainfall in the East Branch Chagrin River basin over a three hour period, with much of the rain falling in a 90 minute to two hour period.

Flash Flood in LAKE, OHIO
From 23-AUG-23 17:50:00 to 23-AUG-23 21:40:00 (EST-5)
Location: LAKESHORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Multiple roads flooded and impassable in Painesville due to heavy rainfall. Some of these roads included the Richmond Street and North State Street underpasses. Radar estimated rainfall of 2 to 2.5 inches fell in a three to four hour period, with 1 to 1.25 inches of rain falling in one hour.

Flash Flood in LORAIN, OHIO
From 23-AUG-23 21:50:00 to 24-AUG-23 00:30:00 (EST-5)
Location: OBERLIN
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash flooding reported in Oberlin and Pittsfield Township due to heavy rainfall. Several reports of flooded basements. OH-303 closed between Pitts Road and Quarry Road due to flash flooding. Radar estimated 2.5 to 3.5 inches of rainfall in a three hour period.

Flash Flood in LAKE, OHIO
From 23-AUG-23 19:30:00 to 23-AUG-23 22:30:00 (EST-5)
Location: WILLOUGHBY
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread road closures due to flash flooding in Willoughby, Eastlake, and Willowick. Multiple water rescues conducted due to vehicles driving into flooded roadways. Road closures in this area included US-2 near Stevens Boulevard, Vine Street just east of US-2, Riverside Boulevard and Riverside Drive, and Lake Shore Boulevard near Vine Street. Radar estimated 2.25 to 3 inches of rainfall in a three to four hour period, with 1 to 1.5 inches of rain falling in the hour immediately preceding the flash flooding.

Flash Flood in LAKE, OHIO
From 23-AUG-23 19:50:00 to 23-AUG-23 23:00:00 (EST-5)
Location: PLEASANT VLY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Widespread flash flooding leading to road closures in Willoughby Hills and Waite Hill. Flooded roadways include Milann Drive, River Road near Beech Hills Drive, River Road near Rivera Ridge Road, Chagrin Drive, and Trailard Drive. Radar estimated 2.25 to 3 inches of rainfall in a three to four hour period, with 1 to 1.5 inches of rain falling in the hour immediately preceding the flash flooding.

Flash Flood in LORAIN, OHIO
From 23-AUG-23 22:15:00 to 24-AUG-23 02:00:00 (EST-5)
Location: BRIGHTON
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Flash flooding in and around Wellington. Lorain County Fairgrounds inundated with more than a foot of standing water, flooding cars and livestock trailers in the fairgrounds parking area, and several barns on the fairground property. Some basement flooding reported in Wellington. OH-18 closed west of Wellington between Oh-511 and Quarry Road and east of Wellington between Hawley Road and West Road. Radar estimated 3 to 4 inches of rainfall in a three hour period.

Flash Flood in LORAIN, OHIO
From 23-AUG-23 21:30:00 to 24-AUG-23 01:00:00 (EST-5)
Location: AMHERST
Flood cause: Heavy Rain
Property damage: 3.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread flash flooding across northern Lorain County due to heavy rainfall. Widespread basement and isolated first floor flooding reported in Lorain, Elyria, Amherst, Avon Lake, Avon, and North Ridgeville. Widespread flooded roadways reported. Post event damage assessments reported hundreds of homes and businesses flooded. Radar estimated rainfall of 3 to 4 inches falling in a three hour period, which matched several measured rain gauge reports from the area.

Flash Flood in CUYAHOGA, OHIO
From 23-AUG-23 19:54:00 to 24-AUG-23 00:00:00 (EST-5)
Location: EAGLE CLIFF
Flood cause: Heavy Rain
Property damage: 750.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread, extensive flash flooding in Cleveland, Lakewood, Rocky River, Westlake, and Bay Village. Interstate 90 flooded with several feet of water with multiple water rescues on both eastbound and westbound lanes near the McKinley Avenue exit. Lakeshore Boulevard and Martin Luther King Boulevard closed due to flooding in Cleveland, with multiple cars stranded in high water. Extensive basement flooding in Rocky River, Lakewood, and Bay Village. Radar estimated 1.5 to 2.25 inches of rainfall in less than three hours, with much of the rainfall falling in less than one hour.

Flood in LORAIN, OHIO
From 24-AUG-23 02:00:00 to 24-AUG-23 10:00:00 (EST-5)
Location: BRIGHTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flooding from standing water at Lorain County Fairgrounds and remaining road closures in and around Wellington after the initial flash flooding subsided.

Flash Flood in CUYAHOGA, OHIO
From 23-AUG-23 19:40:00 to 23-AUG-23 22:10:00 (EST-5)
Location: (CGF)CUYAHOGA CO ARP
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash flooding of area creeks/streams due to heavy rainfall. Road closures reported on Fairmount Boulevard near the Chagrin River and Bishop Road near East Branch Euclid Creek due to flooding. Radar estimated 2.25 to 3.25 inches of rainfall in a three hour period, much of which fell in 90 minutes or less.

Flash Flood in ERIE, OHIO
From 23-AUG-23 22:10:00 to 24-AUG-23 02:15:00 (EST-5)
Location: VERMILION
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Multiple road closures due to flash flooding in eastern Erie County, including in Vermilion and Florence Township. Main Road closed at Chappel Creek due to flooding of the creek. Sperry Road closed between OH-60 and the Erie/Lorain county line. Reports of cars stranded in flooded roadways in Vermilion. Radar estimated 3 to 3.75 inches of rainfall in a three hour period.

Flash Flood in ERIE, OHIO
From 23-AUG-23 23:30:00 to 24-AUG-23 03:30:00 (EST-5)
Location: HURON
Flood cause: Heavy Rain
Property damage: 2.50M
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread flooding across western and central Erie County, including the cities of Sandusky and Huron, Margaretta Township, Perkins Township, Oxford Township, and Huron Township. Officials estimated hundreds of homes impacted by basement flooding per local media reports. Widespread road closures due to flooding. Some of the roads impacted by flooding include US-6 from the Sandusky city limits to OH-269, Homegardner Road between OH-269 and Bardshar Road, Campbell Street at Pipe Creek, Old Railroad Road at Mills Creek, Bogart Road at Pipe Creek and at Patten Tract Road, Patten Tract Road at Fox Road and Mason Road, Ransom Road at Wood Road, and Hull Avenue at Lawrence Avenue. Huron High School damaged by flooding. Animal shelter needed evacuated due to flooding. Several residents requiring evacuation near Pipe Creek near Columbus Avenue. Cars stranded in underpass on Columbus Avenue. Apartment complex flooded out in the southeast portion of the city of Sandusky. Radar estimated 3 to 4.75 inches of rainfall in a three hour period, with the highest amount along the Lake Erie shoreline from Sandusky to Huron.

Flash Flood in LUCAS, OHIO
From 24-AUG-23 03:15:00 to 24-AUG-23 05:45:00 (EST-5)
Location: MAUMEE
Flood cause: Heavy Rain
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Heavy rainfall caused extensive flooding of roadways in the Toledo metro area. Some flooded locations included Secor Road near Sylvania Avenue and also south of Central Avenue, and portions of Interstate 475. Multiple reports of cars being stranded due to driving into flooded roadways. Lower level apartment flooding was also reported in South Toledo. Radar estimates and measured rainfall reports indicated 2.25 to 3 inches of rain fell, primarily in a two hour period.

Flash Flood in SENECA, OHIO
From 24-AUG-23 00:44:00 to 24-AUG-23 01:45:00 (EST-5)
Location: TIFFIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Reports of several streets flooded and impassable in Tiffin. Radar estimated rainfall of 1.25 to 2 inches fell in a 45 to 60 minute period.

Flash Flood in SANDUSKY, OHIO
From 24-AUG-23 00:50:00 to 24-AUG-23 05:40:00 (EST-5)
Location: FREMONT
Flood cause: Heavy Rain
Property damage: 150.00K
Crop damage: 0.00K
Reported by: County Official

Reports of impassable roadway flooding in and just north of Fremont, including flowing water over County Road 73 between Oak Harbor Road and Fangboner Road. Community building in the northern portion of Fremont experienced up to 5 feet of water in the basement of the building. Radar estimated rainfall of 3.25 to 4 inches fell in a 3 to 4 hour period, much of which fell in an initial 45 to 60 minute period, when 1.5 to 2 inches of rain fell in the hour leading up to the flash flood event.

Flash Flood in ASHLAND, OHIO
From 23-AUG-23 22:20:00 to 24-AUG-23 03:00:00 (EST-5)
Location: SULLIVAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

State Route 58 and County Road 281 closed due to flooding of East Branch Black River in Sullivan Township in northeast Ashland County. Radar estimated 3 to 3.5 inches of rainfall in a 2 to 3 hours period.

Flash Flood in SANDUSKY, OHIO
From 24-AUG-23 02:30:00 to 24-AUG-23 05:00:00 (EST-5)
Location: ERLIN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Reports of widespread road closures due to flooded and impassable roadways in northeast Sandusky County. Radar estimated 3 to 3.25 inches of rain fell in a 2 to 3 hour period preceding the flash flood event. Total rainfall of 4 to 4.5 inches fell over a 5 hour period.

Flash Flood in ASHLAND, OHIO
From 23-AUG-23 23:00:00 to 24-AUG-23 03:00:00 (EST-5)
Location: RUGGLES
Flood cause: Heavy Rain
Property damage: 400.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread flash flooding with localized significant impacts across much of northwest and central Ashland County. More than one dozen reported road closures due to flooding of creeks, streams and rivers, with several inches to several feet of flowing water across roadways. Some major roadways closed by flooding include several portions of US-250, US-42, OH-56, OH-302, in addition to several township and county roadways. Four water rescues were reported across this area due to vehicles driving into flooded roadways. Township Road 1275 near the intersection of OH-89 in Perry Township was washed out due to flooding. A vehicle drove into the washed out culvert and two occupants needed to be rescued, and were transported to a local hospital with minor injuries. Radar estimated 2.75 to 3.5 inches of rainfall in a 3 hour period, with a bulk of the rain falling in a 90 minute or less period.

Flash Flood in HURON, OHIO
From 23-AUG-23 23:10:00 to 24-AUG-23 02:10:00 (EST-5)
Location: NORWALK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread road closures due to flooding across Norwalk, Wakeman, and Townsend Township. This includes Wakeman Towline Road at Chappel Creek, Greenwich Milan Townline Road North near Union Road, Lehigh Road south of US-20, and Elm and Water Streets in Norwalk. Radar estimated 2.5 to 4.75 inches of rainfall across this area in a three hour period ending 100 AM EDT August 24, 2023.

Flash Flood in OTTAWA, OHIO
From 23-AUG-23 23:45:00 to 24-AUG-23 04:15:00 (EST-5)
Location: CATAWBA IS
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread roadway and basement flooding across Catawba Island. One water rescue was reported at a campground in Catawba Island. Radar estimated 5.5 to 6 inches of rainfall in a four hour period ending around 400 AM EDT on August 24, 2023, with a bulk of the rain falling in roughly 2.5 hours.

Flash Flood in RICHLAND, OHIO
From 24-AUG-23 00:50:00 to 24-AUG-23 02:30:00 (EST-5)
Location: SHELBY ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Multiple road closures due to flooding in Cass and Plymouth Townships. Flooding of Bear Run and Marsh Run caused flowing water over roadways leading to their closure. This includes London West Road between Broadway Road and Plymouth Springmill Road, London East Road between Fackler Road and Ganges-Five Points Road, and Champion Road between London West Road and Hazel Brush Road. Radar estimated 2 to 3 inches of rainfall in just under 3 hours.

Flood in ASHLAND, OHIO
From 24-AUG-23 11:00:00 to 25-AUG-23 18:30:00 (EST-5)
Location: PERRYSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Moderate flooding along the Black Fork Mohican River near Loudonville. The river rose above the 10 foot flood stage midday on August 24, 2023, cresting at 11.27 feet during the morning of August 25, 2023. Flooding of RIverside Park and a canoe livery reported.

Flood in ASHLAND, OHIO
From 24-AUG-23 03:00:00 to 24-AUG-23 13:00:00 (EST-5)
Location: LAKE FORK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Continued areal flooding across northern Ashland County through the morning hours of August 24, 2023 due to heavy rainfall that began the previous evening. Widespread road closures continued due to flooding of creeks, streams, and rivers. Flooding was prolonged due to additional brief heavy rainfall during the mid morning hours of August 24, 2023.

Flash Flood in OTTAWA, OHIO
From 24-AUG-23 00:00:00 to 24-AUG-23 04:00:00 (EST-5)
Location: PORT CLINTON
Flood cause: Heavy Rain
Property damage: 400.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Reports of widespread flash flooding in Port Clinton. Multiple flooded and impassable roadways reported along with widespread basement flooding. Radar estimated around 4 inches of rainfall in just under a 3 hour period ending 300 AM EDT on August 24, 2023, with total rainfall of 5 to 5.5 inches ending 500 AM EDT on August 24, 2023.

Flash Flood in RICHLAND, OHIO
From 23-AUG-23 23:30:00 to 24-AUG-23 02:30:00 (EST-5)
Location: PINHOOK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread road closures due to flooding in and around Mansfield, including OH-13 and US-30 and the railroad underpass at the OH-430 and US-42 split. Mt. Zion road closed due to flooding of Rocky Fork between Smart Road and Crimson Road. USGS stream gage on the Rocky Fork at Lucas indicated a 5.7 ft. rise in the river from 10 PM to 3 AM EDT. Radar estimated rainfall of 2.75 to 3.25 inches fell in this area in a 2.5 to 3 hour period.

Flash Flood in OTTAWA, OHIO
From 23-AUG-23 23:30:00 to 24-AUG-23 05:00:00 (EST-5)
Location: PUT IN BAY ARPT
Flood cause: Heavy Rain
Property damage: 750.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Extensive flash flooding on South Bass Island, with widespread street flooding and widespread basement flooding. Flooding of airport runway on the island. Radar estimated 6.5 to 7 inches of rainfall in a 4.5 hour period ending around 400 AM EDT on August 24, 2023, with 4 to 4.5 inches of rain falling in roughly 2.5 hours.

Flash Flood in HURON, OHIO
From 24-AUG-23 00:20:00 to 24-AUG-23 02:10:00 (EST-5)
Location: STRONGS RIDGE
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread road closures due to flooding across western Huron County. Some roads include Section Line Road 30 North at Megginson Creek, Section Line Road 30 South at Mud Run, and Townline Road 131 West near OH-61. Basement flooding was reported in Bellevue. Radar estimated 2 to 3 inches of rainfall in a three hour period.

Flash Flood in MEDINA, OHIO
From 23-AUG-23 22:00:00 to 24-AUG-23 01:10:00 (EST-5)
Location: BURBANK STATION
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread road closures across western Medina County due to flash flooding. Water rescue reported on Richman Road in Chatham Township after vehicle drove into roadway flooded up to 4 feet in water depth and swept off roadway. Reported road closures include Spencer Mills Road near Coon Creek, River Corners Road near East Branch Black River, Firestone Road near East Branch Black River, Willow Road near Repp Run, and Friendsville Road near Killbuck Creek. Radar estimated rainfall of 2.25 to 3.5 inches in a three hour period ending at Midnight EDT on August 24, 2023.

Flash Flood in CUYAHOGA, OHIO
From 23-AUG-23 20:15:00 to 23-AUG-23 22:30:00 (EST-5)
Location: BEDFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Multiple road closures in and around Solon due to flash flooding. Road closures include US-422 at Brainard Road and Bainbridge Road near Harper Road. Radar estimated 1.75 to 2.25 inches of rainfall in a three hour period, with most of the rain falling in a 60 to 90 minute period.