Making sense of what's coming - Jan 10-14th Winter Storm and Lake Effect Snow Event

Sunday's storm is looking more and more like it's going to be all snow, which means we're going to probably see a great deal of snow from it. It's way too early to tell how much, as snow to liquid ratios are going to be in question. Where the freezing line sits is going to be a big deal in terms of who sees how much snow, but I wouldn't be surprised if 6-10" affect portions of the state.

The bigger deal is that after the storm passes, we're not going to be done seeing snow until probably Thursday. This is because the very powerful arctic blast that's going to come behind the storm is going to flow over the Great Lakes which are nearly unprecedentedly warm.

The effect is going to be one that I cannot yet say.

The latest GFS runs forecast this amount of snow by Thursday. The 10:1 snow to liquid ratio used in this image is undoubtedly flawed; the deep freezing arctic temperatures are going to make the ratio closer to 12:1, 15:1... perhaps even 20:1. The "mini storms" which form over the lakes (called "lake induced mesoscale convective voritices") form in the same manner that thunderstorms do. When the temperature differential is going to be this big, you get the same type of explosive potential that you see in severe thunderstorms. You're not going to see hail and tornadoes like you do with severe thunderstorms, but you will see torrential amounts of precipitation fall in relatively unpredictable places. That precipitation will be all snow.

The big kicker is that with lake temperatures being what they are, those storms can grow much bigger and stronger, and can survive farther inland. That means that significant lake effect snow might even occur outside the snowbelts. Those within will unquestionably be buried. As to how much snow to expect, the jury is still out. We could break records. We could see a decent amount but still stay within reason. Or we could wind up seeing more what the GFS is predicting.

The fact is this: do not yet buy into any snow predictor images you see floating around the internet that go beyond 48 hours. Forecasting snow of this type is like trying to plot exactly where thunderstorms will develop 48 hours in advance - you can assign a general risk area, and even predict what hazards people within the area are likely to face, but you cannot assign an exact number nor even have high confidence until a couple days out from the event at the very least. 

To summarize:

• Begin preparations for a significant winter storm regardless of where you may live in the state.
• If you do live in the snowbelts, make preparations for a severe blizzard.
• The snow will not begin until Sunday. The initial storm could drop anywhere from 4-6" to 6-10" depending on snow to liquid ratios.
• Lake effect snow will begin in the wake of the storm. These type of snow squalls will form similarly to thunderstorms making it very difficult to predict exactly who will see the most snow and just how much will fall.