[1][2] 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.

[4] 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.

[7] 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.

[6][13][14] As a result, this was the first time flash flood emergencies were issued from the National Weather Service in Paducah, Kentucky for the Jackson Purchase region of the state.

[19][22] 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.