Flash Flood — Ottawa, Ohio

2018-06-13 · near Oak Harbor, Ottawa, Ohio

Event narrative

Three rounds of torrential rain moved across Ottawa County on the evening of June 12th between 8 pm and midnight. The heaviest rain occurred around 1030 pm with rainfall rates estimated at over 5 inches per hour lasting for 45 minutes. Unofficial rain gauges in the area reported storm total rainfall amounts of 5 to 6 inches between Oak Harbor and Port Clinton, with one cocorahs station reporting 5.50 inches over Port Clinton. A rain gauge in Catawba Island reported as much as 8 inches, though this cannot be verified. Though a lakeside and relatively flat terrain the area is flood prone. Flooding was notable in this event due the intensity of the rainfall which overwhelmed storm drainage systems. The Portage River, which flows through Ottawa County to its mouth at Sandusky Bay, was elevated but did not flood. Lake Erie, another source for storm water output, was elevated at the time of the rainfall contributing to poor storm drainage.

Local officials declared a State of Emergency for Port Clinton and Oak Harbor due to extensive flooding. The primary impacts were widespread basement flooding and road closures. Hardest hit in Port Clinton were Madison, Lee, Taft, and Columbia Streets. Flood waters reached the front doors of many homes as neighborhood storm drains were overwhelmed. At least one basement wall collapsed. Following a CERT survey, there were at least 6 homes with major damage, 51 with minor damage, and 134 affected. The area hospital flooded with 2-3 inches in the lobby, gift shop, and radiology department, along with the south parking lot. In Port Clinton alone up to 35 roads were either closed or had reports of high water between 2 and 3 feet deep. In Oak Harbor Ohio 19 between Ohio 163 and Ottawa Street was flooded. The primary impacts in Oak Harbor was flooded basements. Total damages estimated around $1.25 M.

Wider weather episode

Diurnal thunderstorms over northern Ohio were on the evening of June 12th became enhanced along a lake breeze boundary over Ottawa County. The environment that evening was anomalously moist with storms capable of producing torrential rain. The storms initially moved into Ottawa County shortly after 8 pm. Another round of storms moved along the stationary lake breeze boundary draped across Ottawa and Wood Counties between 10 and 11 pm. A third wave of storms moved into Ottawa County around midnight. The result of these three rounds of heavy rain was widespread flash flooding across Port Clinton and Oak Harbor.

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Source: NOAA Storm Events Database, event_id 752934. Narrative written by the NWS forecast office that issued the report.