An upper level trough will approach the region tonight with a surface low passing through the southern states and Tennessee Valley. Gulf moisture will accompany this low pressure system, helping to induce precipitation along and north of the surface cold front. (See image below from HPC with expected surface features for Tonight).
Rain continues across central Kentucky and southern Indiana tonight. As this precipitation comes to an end, a quick and brief changeover to snow is possible. As a result, light snow accumulations may occur Tuesday morning mainly on grassy and elevated surfaces in the area shaded on the map below in light blue, mainly across the northern Bluegrass. With temperatures falling to around or below freezing Tuesday morning over portions of southern Indiana and north central Kentucky, any remaining liquid or light snow may cause slick spots on elevated road surfaces (bridges and overpasses). Travelers in this area should exercise caution on the Tuesday morning commute.