Superstorm Sandy brought record rainfall and major flooding to northern portions of Ohio in late October 2012. The flooding was the result of three consecutive weather events; a cold front, hurricane Sandy remnants, and lake enhanced showers. Rain started on October 26th as a slow moving cold front moved into the Ohio Valley. This front brought widespread 0.75 to 2.0 inches of rainfall to northern Ohio, highest near the lake. This rainfall did not produce flooding, but it raised streamflows and reduced flash flood guidance to around 1 inch for 6 hours.
By Monday the remnants of Hurricane Sandy moved into Pennsylvania, and the pressure gradient between it and high pressure over Missouri produced storm force winds over Lake Erie. Moisture from Sandy moved into the region producing an additional rainfall of 2 to 3 inches by Tuesday the 30th. Rain continued at a rate averaging 0.1-0.2 per hour for the day, but increased to 0.75 per hour overnight and early Wednesday morning. This band of heavier rain caused the rivers which were receding to once again rise.
Areal flooding was limited to more northern counties; however some small streams and creeks came out of their banks as far south as Ashland County. Numerous roads were closed due to flooding over Cuyahoga, Lake, and Medina Counties from the persistent rain. A flood watch was in effect for the lake front counties and flood advisories were issued during the event.
A few dozen homes and businesses were impacted as water inundated basements or first floors. A number of homes affected were located in the flood plain of the rivers or along the shoreline where the raised lake level combined with the increased streamflows to produce flooding in areas not typically affected. Two rivers along the lakeshore reached major flood, the Cuyahoga and the Huron Rivers. The rest of the Lake Erie tributaries saw minor or moderate flooding. Many basements flooded further inland as sump pumps failed due to power outages.