Kentucky’s had a particularly wet year with average rainfall totaling about 17 inches above normal, said Tom Reaugh, forecaster at the National Weather Service in Louisville.
This year’s heavy rains have caused the worst river flooding since 1997, forced the Metropolitan Sewer District to dump billions of gallons of sewage into Louisville waterways and contributed to at least two deaths over the last two weeks.
“This has been a particularly wet year in Louisville. Since the first of January we’ve had 49.09 inches of rainfall,” Reaugh said.
The rain on Saturday night broke a daily record and brought minor flooding to parts of Southern Indiana and Northern Kentucky along the Interstate 64 corridor.
The remnants of Tropical Storm Gordon moved north from the Gulf Coast, dropping 3.84 inches of rain at the Louisville International Airport. That broke the old record of 1.67 inches set back in 1876, according to the National Weather Service.
Northern Kentucky’s seen at least two “top ten” rain events in the last month, including Saturday’s storm, said Trent Schade, National Oceanic and Atmospheric Administration hydrologist.
“It is a pretty remarkably wet summer and early fall,” Schade said.
On the last day of August, 1.21 inches of rain — another daily record — swept 15-year-old Davey Albright into a drainage pipe, according to news reports. The Trinity High School student died a week later.
Saturday’s rains contributed to the death of a Yellow Cab taxi driver who stalled in flood waters in a railroad underpass at Oak and 13th streets, according to the Courier Journal.
Often the city floods for one of two reasons: long-term rain events saturate the ground and raise the river levels, or heavy rains drop a large volume of water in a short amount of time.
Surfaces like asphalt and concrete contribute to the flooding leaving rain with nowhere to go, like what’s seen in this video Courier Journal reporter Thomas Novelly shot in Old Lousiville this weekend.
At the same time, the city’s aging sewer infrastructure is unable to cope with the high volume of stormwater generated by the heavy rains.
That contributes to flooding, but it also causes overflows in the streets and forces the Metropolitan Sewer District to release excess stormwater and raw sewage into the Ohio River and Beargrass Creek.
MSD spokeswoman Sheryl Lauder said there were overflows last weekend, but has not yet provided amounts.
During the heavy rains this spring, MSD estimated it released about four billion gallons of stormwater and sewage over five days.
It’s difficult to ascertain the impact our changing climate has had on this year’s weather. There are always wetter and drier years, Reaugh said.
Also, heavy rains can fall in isolated areas. Where those rains fall has a lot to do with with how records change, he said. It’s also difficult to say that any single weather event is caused by climate change.
With all those caveats in mind, climate experts say Louisville’s weather is changing and the city will see both more droughts and more large storms over the coming decades.
Already, Kentucky’s average temperature increased 1.41 degrees over the last 30 years, according to climate data from the Associated Press.
Increasing temperatures mean increasing variability, meaning wetter and drier patterns. Warming temperatures mean more hot summer days, higher likelihoods for droughts and an increased risk of large storms.
Despite Hurricane Florence looming off the coast, meteorologists say the rest of the week should be fairly dry with temperatures warming.
Ironically, when significant hurricanes hit the east coast, the Ohio Valley experiences relatively dry weather, Reaugh said.
“Oftentimes to the west of a hurricane you have sinking air, and sinking air tends to discourage precipitation from forming,” he said.
Reaugh said it’s unlikely that Louisville will feel any direct impact from the hurricane.
The heaviest rains should stay just east of Kentucky, but residents in the eastern part of the state should keep an eye on the weather, he said.
This post has been updated.