After a break this weekend and early this coming week from the cold and active pattern we've seen the past several weeks across the Midwest, including here in Illinois, things look to ramp up again as we get into the middle and end of next week with what looks like several chances for rounds of wintry weather. The pattern going forward after next week looks like one of a return to below normal temperatures across portions of the Midwest along with several chances for snow producing systems across the region. I dig into the details below of what we could potentially expect next week and the overall setup that could lead to the wintry weather.
As we go into the beginning and middle portion of next week, ridging will build across the Midwest and eastern United States as a upper level low carves out a trough across the western United States This large scale synoptic pattern is usually favorable for warming (warm air advection seen by the red arrows) across the central plains and into the Midwest.
Even though the above pattern will be favorable for large scale warming, very cold air will be located across the northern plains thanks to a strong surface high located near eastern Montana and into Canada. This is going to lead to an impressive baroclinic zone, or tight thermal gradient across the heart of the country, or more so a fight between the warm air to the south and cold air to the north. On the image below, the baroclinic zone is circled in red and is the divider between the cold and warm air across the country.
By the time we get towards Tuesday and Wednesday of next week, several smaller disturbances will eject out through the strong southwesterly mid-level jet stream across the plains and into the Midwest, each one inducing a period of insentropic lift and warm air advection to our southwest. This will then lead to blossoming areas of precipitation across the central plains and into the Midwest with the first threat of any wintry precipitation Tuesday night and into Wednesday morning across the northern half of Illinois looking at current model guidance. After that, model guidance is suggesting the threat of a bigger system if and when the main upper level low tries to eject out into the plains and eventually our area. The loop below runs from Tuesday afternoon through late Thursday night next week, showing multiple rounds of wintry precipitation across portions of Illinois.
As you can see below, the best potential for something substantial will come mid-late next week as highlighted by the image below valid next Thursday. Obviously we are still around 3-5 days from these potential several events so expect things to change but updates will continue over the coming days.