Kentucky Appears To Have Set A New 24-Hour Rainfall Record

Kentucky Flash Flood Emergency

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Western Kentucky's historic flooding on Wednesday was fueled by rainfall that has preliminarily broken the state's all-time 24-hour record.

A​ weather station in Graves County reported a rainfall total of 11.28 inches in just 13 hours, according the National Weather Service in Paducah. That tops the state's current 24-hour record of 10.48 inches set in Louisville on March 1, 1997.

An ad hoc NOAA State Climate Extremes Committee will have to perform a thorough investigation to determine whether the total is valid in order to confirm the new record.

T​his is the second state to set a new preliminary 24-hour rainfall record this year.

A​ whopping 25.91 inches of rain was recorded in 24 hours during historic flooding in Fort Lauderdale in mid-April. That total is under review by a NOAA committee to determine whether it broke the official state record for Florida, according to the Florida Climate Center.

I​t's possible that higher totals might have occurred in the state's history, but weren't measured by instrumentation that was deemed reliable, or they were estimates.

H​ere's how these totals stack up against records in other states.

U.S. 24-Hour Rainfall Records

Records for 24-hour rainfall in the United States range from less than 6 inches to more than 4 feet, according to NOAA.

C​olorado, Delaware, Michigan, Minnesota, Nevada, New York, Oregon, South Dakota and Tennessee are other states that have set records within this century. It's a sign of how climate change is making intense, heavy rainfall events ​more likely.

In the Lower 48, it's no surprise that the states with the most extreme 24-hour rainfall totals are located in the Southeast and along the Gulf Coast, as these are the areas most likely to take a direct hit from a tropical storm or hurricane.

The Lower 48 record was set in Texas July 25-26, 1979, when Tropical Storm Claudette brought 42 inches of rain to the town of Alvin in 24 hours.

In the Southeast, the 24-hour rainfall extremes are mainly between 20 and 25 inches. The exception there is South Carolina, with a 24-hour extreme of 14.8 inches.

Some of the lowest extreme rainfall totals are in the Northern Plains, Rockies and Great Basin. For example, the most extreme 24-hour rainfall total on record in Utah is only 5.1 inches, the smallest of all 50 states. This is because these areas are far removed from ocean influences, including tropical storms and hurricanes, and have a rather dry climate overall.

Most of the Northeast has 24-hour rainfall extremes between 10 and 15 inches, with the exception being Massachusetts at 18.2 inches. Additionally, these extremes generally took place during the summer months or early in the fall.

O​ne state total missing from the NOAA list is Kansas. Their record is under investigation after NOAA found an error in the state's previously reported 24-hour record.

Chris Dolce has been a senior meteorologist with weather.com for over 10 years after beginning his career with The Weather Channel in the early 2000s

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