July 2023 Western Kentucky floods

In a two-day period from July 18 to July 19, 2023, significant flooding occurred across western portions of Kentucky, southern Illinois, southeastern Missouri, and northwestern Tennessee caused by stalled heavy thunderstorms which brought high rainfall rates to numerous locations across western Kentucky. The flooding event also inundated locations previously hit by the 2021 Western Kentucky tornado. Numerous homes were flooded across western Kentucky, and several flash flood emergencies were issued for locations in western Kentucky and southern Illinois as well.

Meteorological synopsis
Showers and thunderstorms developed ahead of a mesoscale convective system along a low-level convergent axis on the afternoon of July 18 across portions of southeast Missouri. Favorable precipitable water values around 1.7-1.9 inches, along with wind shear around 50-60 knots, and most-unstable convective available potential energy (CAPE) in the 2000 values, yielded conditions for the developed thunderstorms to intensify and produce heavy rainfall.

The next day, a moderate risk of excessive rainfall was issued by the Weather Prediction Center, and a flood watch was issued for Kentucky, Illinois, Tennessee, and Missouri. Convection initiated in the vicinity of the Tri-state area in the early morning hours of July 19, and precipitable water values increased from the previous day to 1.8-2.3 inches, and a strong boundary layer moisture convergence from an isentropic ascent, combined with the same CAPE values from the previous day, allowed a strong low level jet and training convection to rapidly increase in coverage across central Missouri and head southeastward along a stationary front, causing heavy rainfall. Another mesoscale convective system developed several hours later, leading to additional high rates of rainfall. Convection continued to form on the afternoon of July 19 as 850-millibar inflow at 20-30 knots and favorable thermodyamics led to additional rainfall across southeast Missouri, southern Illinois, western Kentucky, and northwest Tennessee.

Impact
Numerous homes were flooded in Mayfield and Wingo. Cars were submerged on flooded roads in Graves County. Portions of I-69, the Purchase Parkway, and KY 80 were flooded. Flash flood warnings were issued for western Kentucky, southern Illinois, southeastern Missouri, and northwestern Tennessee, including Carbondale, Illinois, Cape Girardeau, Missouri, and Paris, Tennessee. Rare flash flood emergencies were issued for Mayfield, Paducah, Fancy Farm, and surrounding areas, and included areas impacted by the 2021 Western Kentucky tornado. A flash flood emergency was also issued for LaCenter, Kentucky, and Mounds, Illinois, and as far north as Karnak, Illinois. Crop losses also occurred in western Kentucky. 19,433 power outages occurred at one point during the flooding event. 1 person was injured and six water rescues were completed in Graves County.

Near Mayfield, 11.28 in of rain fell, setting a new record rainfall in Kentucky. 6.9 in of rainfall fell in Paducah, Kentucky, which was the second—highest daily record there. The event was also considered a 1 in a 1,000-year event.

Aftermath
Kentucky Governor Andy Beshear declared a state of emergency for Mayfield and surrounding areas, and toured the flooded areas. Local emergencies were declared in Carlisle, Fulton, Graves, Hickman, and Lee counties in Kentucky, and also in the cities of Arlington, Bardwell, Clinton, Cumberland, and Mayfield. Western Kentucky University offered free early move-ins to summer housing for flood victims. Damage assessments by the Kentucky Emergency Management Agency were completed in 47 buildings, including 41 homes and 6 businesses. A shelter was opened for displaced residents following the disaster.