December 16: Round 2

Round 1 was a decent snowfall for all of us in Central Ohio. I believe the only areas left disappointed would be north of a line from Marysville to Delaware, and even they got at least an inch of snow.

Moving on to Round 2, and we have a much more difficult forecast to try and nail. It's our typical mixed bag, splitting the area in half with snow north, rain south, and an icy mess in between. So who gets what? That's what I'll try and lay out for you.

The Setup
A second southern low in as many days will be racing in to the Ohio Valley.

This one has a lot more moisture, and more warm air to push up and over the cold air we have in place. For Southern Ohio, that means enough warm air reaches the surface to bring a cold rain all afternoon and night. But for Central Ohio, it's the split.

The Event
Between 3pm and 4pm this afternoon we'll see precipitation begin to overtake Central Ohio. Just about everyone should start as rain with our temperatures in the upper 30s, but as the sun sets, diurnal heating will leave us with tumbling temps.

What happens after sunset will be messy and hard to pin down for exact locations. So here's an idea of what we could see:

I don't think these regions I've drawn are set in stone, either. As with most of these scenarios, a small tug north or south could drastically change who sees what.

Frankly I don't think models have a good handle on this. Some want to give all rain to our area and others are much more aggressive with snow as far south as Circleville to Lancaster line. I want to stay somewhere in the middle, with the focus for transition right around I-71 (as usual).

I've also drawn the Rain/Sleet/Snow area much larger than what most local news outlets will because of that extreme uncertainty. We could see an interesting temperature profile on the 7pm sounding out of ILN with a big clash of cold and warm air aloft.

Prediction
This one is super hard to determine, but I've seen this type of storm a million times in Central Ohio, and nine times out of ten the warm air advances further north than anyone expects. Here's what I think snowfall looks like:

These totals could move north or south by as many as 50 miles depending on what the temperature profile looks like overnight. I'll be posting on Twitter as precip starts and give you updates on what changes we could expect to this forecast.