Colder Weather For New Year's

We have been stuck in an above average pattern thus far this cold season. That has been a result of El Niño displacing the jet stream to our north. That pattern results in milder temperatures for the Upper Midwest, Great Lakes, and Northern Plains. However, forecast models are picking up on a pattern change as we head towards New Year's and ring in 2016.
That pattern change is in the form of much colder air. A breakdown in the ridge that has dominated in the eastern half of the country will occur the week of New Year's, which will allow colder air to move in from Canada. That is evident on the map above that shows the geopotential heights. That is a meteorological term that could be discussed for months. What you need to know is that areas of blue and green represent lower heights, or colder temperatures. On the other hand, the areas of orange and red--what we have been seeing this winter--are large heights, or warmer than average temperatures.

This pattern has been showing up on forecast models for quite some time, so there is consistency among the models, which is reassuring. We will get colder? Yes. How cold? It is difficult to answer that with high confidence as of right now. However, one forecast model is showing temperatures during the nighttime around New Year's Day in the teens and potentially single digits.

In fact, here are the projected temperatures on the morning of January 1st. Note the influx of much colder air from Canada resulting in much of the country seeing sub-freezing temperatures. Teens are showing up over Northern Illinois and Southern Wisconsin, which would be some of the coldest air we've seen this year. Is this going to happen? Not exactly. This is simply a model's thoughts on what the morning low temperatures will be on January 1st. What is important is that it shows the colder air like the long-range model above shows, and it shows how cold we could get.

Does the cold mean we will also see more wintry weather like snow? Not necessarily. It increases our chances of seeing snow simply because the colder air will allow more frozen precipitation to fall instead of plain rain. You still need a storm system and/or low pressure to develop and bring precipitation with them. Just having cold air in place is not enough. The good news for any snow lovers out there is the models have been very consistently showing a low pressure system developing in Texas on Sunday and strengthening as it moves northeastward towards the Stateline.

That low's exact track will dictate whether we see snow or rain or a mix. If enough cold air can hold its place over the region, then we could see much more snow. If the low tracks closer to Rockford, it will pull warmer air with it, which would hinder our chances of seeing snow. Currently, the models track the low over Champaign, if averaged together. That would allow enough cold air to be in place to support some snow. How much? That is impossible to say with high levels of accuracy as of now, but one model is showing several inches. Here it is: