National Weather Service (NWS) meteorologists issued urgent flash flood warnings for nearly 1 million people in Louisville, Kentucky, and surrounding areas on Tuesday after the region saw more than a month's worth of rain in only a few hours.
"This will be the third wettest day for Louisville in October ever," NWS meteorologist Chase Graham told Newsweek. "This is an unusual event."
Behind extreme heat, flooding is the second leading cause of weather-related deaths. During periods of heavy rainfall, rivers and streams can rise rapidly. Flash floods give people little time to act, making any alert extremely important.
Louisville's average monthly rainfall for October is approximately 3.6 inches. So far today, the storm has produced 4.7 inches of rain.
Rain began to fall around 4:30 a.m. local time, but the heaviest amounts have fallen between 9 a.m. and 1 p.m., Graham said.
NWS Louisville has issued flash flood warnings for Bullitt County, Jefferson County, Shelby County and Spencer County.
"At 1214 PM EDT, Louisville Jefferson County Emergency Management reported thunderstorms producing heavy rain in Louisville," one of the warnings said. "Between 2 and 4 inches of rain have fallen. Additional rainfall amounts of 0.5 to 1 inch are possible in the warned area. Flash flooding is already occurring."
The warning went on to add that the flooding was "life-threatening" and that creeks, streams, urban areas, highways, streets and underpasses could flood during the event.
The heavy rain is accompanying a cold front that is moving across the region. In addition to the flash flood warnings, a flood advisory, a flood warning, and a hazardous weather outlook are also in place in Kentucky.
NWS meteorologist Chase Graham told Newsweek: "The back edge of the heavier rain is starting to push out of the warning area. Behind it, there are some light rain showers, but nothing like the rainfall rates we were seeing this morning."
NWS Louisville in a flash flood warning: "There have been several reports of water-related calls for service across Louisville. Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. Be aware of your surroundings and do not drive on flooded roads."
NWS Louisville in a hazardous weather outlook: "Widespread showers and thunderstorms continue today. Moderate to heavy rainfall will lead to 1-3 inches of rain today, which could result in some localized flooding issues. Lightning will be possible with any embedded storms today."
The worst of the rain appears to be moving out of the area soon. The flash flood warning will remain in place until 6 p.m. local time.