The stalled frontal boundary will slowly move north across the area today as a warm front. Showers and thunderstorms will continue to develop along this boundary today. An additional one to two inches of rain will be possible along and north of the Ohio River today. Further south this amount of rain will be possible in areas that see repeated showers and thunderstorms. Thus a Flash Flood Watch remains in effect through this evening across much of the region.
Though there may be a brief break in the the rain late this evening, showers and storms will develop again overnight as a cold front approaches from the west and stalls out. The better chance for widespread heavy rain will be Tuesday night through Wednesday as another area of low pressure moves northeast along the stalled boundary. Another three to five inches of rain in 24 hours could fall across central Kentucky during this time frame. This will lead to to additional river rises and flash flooding.
Below is a graphic from the Hydrometeorological Prediction Center for rainfall totals through Thursday morning.