Certainly an interesting setup later tonight/early Friday
NOW-6PM: Very light snow/flurries possible. Drizzle or sprinkles south...if anything. 40s south, 30s north.
6pm-12AM: Snow starts to increase around southern IN and up I-71. Some light accumulations possible and slick road potential starts to increase. At this time, this looks to stay north of Louisville but wet roads expected if anything did develop.
12AM-4AM: Crucial time period. Energy moves in to enhance precipitation rates for locations near I-64. This is where a few degrees makes a difference between a heavy wet snow and a cold rain or even freezing rain. The air aloft is trending colder on the data and we are leaning more toward the snow idea at this time.
4AM-7AM: Snow continues near the city and points north/east. Changing to rain for areas south/west. Slick roads likely in the snow zone, yet improving to slush/wet roads as we push beyond sunrise.
7AM-NOON: Any wintry weather changing to rain SW to NE. Improving roads drastically.
This is a setup that certainly supports a light coating to an inch of wet snow for areas along/north of the Parkways. It is the piece of energy that moves in after midnight that is concerning that could allow for a nice thumping of snow in localized areas. I am talking about 2″ + totals. But where will that be? I think locations near I-64 stand the better chance at this time but it will be right on the edge of the rain/snow line.
This one is tough. The air aloft certainly is cold with the lowest 1000 feet in question. You can still get heavy snow at 35° in this setup that will accumulate on grassy areas. Roads slushy or wet. But if we cool the surface air down to 32°, we have a whole other ballgame on road conditions. Confidence is medium at best right now. It will be very important to stay close to forecast updates over the next 18 hours as we continue to analyze the data coming in.