This is my update for the Winter weather for New Years Day.

There is still some model disagreement with the winter storm tomorrow morning. Overall a good swath of ice in the mid Mississippi River valley as well as some snow as well. 

First I will discuss what causes Freezing Rain/Sleet/Snow. 

Here in the first weather sounding shows Freezing Rain. In all pictures, the diagonal purple line shows the freezing line, and the red circle shows temperatures above freezing and the blue circles show below freezing temperatures. With this one (compare this with the others), this shows a large warm, inversion layer  above the surface with a slim area of below freezing at the surface. Here's the picture below 

Next I have the sounding with Sleet. This shows a small inversion layer in the mid levels, barely above freezing, with the rest after it between that and the surface below freezing, as seen below 

Here is a sounding with snow, which shows the temperatures below freezing the entire sounding!

NOW for the forecast:

This is still very tricky to do but I'll give it a shot. 

Generally across central IL, totals for ice will be .1-.3 with some high totals possible/likely. There's a lot of factors that go into this so a small change can be the different between a glaze and an inch of ice. These totals are the amount of ice accumulated before rain changes and settles in. Here is the ice and snow totals below. The large snow amounts of snow is where snow is the main form of precipitation, and the lesser amounts in central IL is snow that falls Friday afternoon after the rain. 

Here are the forecast start times of freezing precipitation as well

Thanks for reading and hopefully this does not become as bad as some models are showing it at the moment!

Good evening!

This will be my first post on my sight. I decided back in November to make a weather blog section of my site where I can share my briefings and forecasts instead of cluttering my Facebook with them and I can actually find them when I want to go back and revisit the briefings, plus it's somewhat easier to do this way!

We have an interesting system coming into the Midwest here on New Year's Day, 2021. There's a potential of a possible Ice Storm here in some areas. There are still some uncertainties which will become clearer during the day Thursday, in which I will make another post Thursday evening when the models have more of an agreement.

Generally, the system arrives Thursday night into Arkansas and moves northeast into the lower Wabash River region Friday afternoon. Freezing Rain will start out about anywhere in IL, depending on where you are. The Freezing Rain will start along the I72 corridor around 4-6am Friday morning. All models have it changing to rain at some point but whether it rains most of the time (Track 1) or very little of the time (which means much more freezing rain, Track 2) is still uncertain. 

Track 1, which the NAM seems to have stayed with, depicts a system that tracks more north, in which case shifts the area of freezing rain concern more to the north. Here's a map I created below showing this.
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Track 2, which the HRRR and RAP are sticking with, tracks the system more south, in which case shifts the area of Freezing Rain more to the south. Here's a map below I made. 

This is where things stand right now with this system. I will have another update Thursday Night, and hopefully there will be more agreement by then. There is also a possibility of some light snow in central IL Saturday night that is still unclear as well!

Thanks for reading!

Colin Dobson