Lake Erie's thousand-year storm that flooded Kelleys Island and dropped 17 inches of rain

(FOX 2) - A small island in Lake Erie was met with torrential rains that dropped a historic volume of water earlier this summer.

The one-in-a-thousand year weather event took place over Kelleys Island, off the coast of Ohio, overnight on July 5 and 6. Fortunately, the rain had somewhere to drain.

Along the way, water flooded roads, pooled in basements, and shut down island operations for days. 

Kelleys Island historic rainfall

Big picture view:

Over 17 inches of rain fell in approximately six hours overnight from July 5 to 6 on Kelleys Island. 

There are various factors that fed the system that soaked the island, including Lake Erie's higher-than-average water temperatures. However, according to FOX 2 meteorologist Derek Kevra, the biggest ingredient from the storm was what it lacked: movement.

"What happened with Kelleys Island and what made it different than just a regular rain cloud is it didn't move," he said. "Usually thunderstorms - they move west to east. In this case, you had this gigantic rain cloud form over Kelleys Island. There were no steering currents within the atmosphere."

Thunderstorms generate because of moisture builds in the air. This development continues until it reaches a threshold where all that water is released and falls back to Earth.

During that process, low, mid-level, and high wind victors push and pull the system around. But lacking any movement, the storm will continue dumping water — but in the same place.

By the numbers:

It can be tricky to visualize what a one-in-a-thousand-year storm looks like.

In this case, the rain that fell dropped during approximately a six-hour time period. It averaged out to approximately three inches of rain per hour. The 17 inches of rain added up to half-a-year's worth of rain in a single evening. 

In a separate incident in 2023, Put-In-Bay, also off the coast of Ohio in Lake Erie, received between 8 and 12 inches of rain. 

Lake Erie temperatures

Dig deeper:

The early July storms were also fed by Lake Erie's above-average temperatures. Because the lake is the shallowest of the Great Lakes, it is frequently the warmest in the region.

But high summer temperatures and mild winter temperatures have fueled the lake's influence over weather patterns in the area. On July 5, it was 73 degrees, about four degrees above normal.

That warm lake water added moisture and energy to the atmosphere, which fed the thunderstorm and increased its intensity. 

‘The island rallies’

Local perspective:

Zoey Leonard, executive director of the Kelleys Island Chamber of Commerce, first learned of the storms when she woke in the middle of the night and texted her mom.

"I said ‘are you okay’? and she said ‘no’," Leonard said. "They had a very busy day of cleaning and getting lots of people up, but the island rallies and was able to get it turned around very quickly."

While access to the island remained throughout the ordeal, travel around it was disrupted by flooded roads. 

"Our EMS, our police, village crews, and a lot of volunteers, also the outside agencies, came in and really rallied and cleaned the place up and helped make it look like nothing ever happened."

She said most of the damage after the storm was residential. 

"There's only about 200 people year round," Leonard said. "Everybody knows everybody and everybody is willing to help everybody. There's people that were on the mainland that were bringing supplies over."

Great LakesBrother Nature