Snow showers are to sweep into the Chicago area through Friday night as our winter storm’s movement slows beneath an upper air blocking pattern.

Bursts of snow embedded in our slow moving storm’s gusty “backwash” flow may lay down a modest cover of snow from time to time into Friday night. With no residual road chemicals down and temps trending lower, the potential for slippery spots developing is an issue which should be monitored by motorists.

Temps, which averaged 38-deg last weekend, are to come in 17-deg colder this weekend with daytime highs which remain in the 20s and nighttime lows in the teens.

Our big upper low is far from saying goodbye and clearing our area is to hang around. It’s hemmed in by two huge “omega” blocks in the upper atmosphere — one over western North America; the other over eastern Canada. These have slowed the eastward movement of the storm which means the Chicago area will continue dealing with clouds and wind with this system into the coming weekend. Gusts are to reach or exceed 30 mph at time Friday and Saturday then wane a bit Sunday.

Cold Week Ahead Next Week

Longer range, the real arctic chill takes hold next week with two periods then being monitored for some possible snow

When the books close on this week, temps will have averaged 33-deg. But–underscoring the fact cold air is tightening its grip on the metro area is the face next week is to average 11-deg—a jarring 22-deg drop. That translates to daytime temps which drop to the teens Wednesday next week through the Christmas weekend which follows.

Multiple Chances for Snow

An area of light snow appears a possibility Monday night into a portion of Tuesday as the first of two arctic surges makes its move on the area.

The handling of a second potential area of snow continues a challenge for computer models Wed night and Thursday.

Wednesday night’s European model run developed a full blown winter storm with accumulating snow in the area–something it was alone in doing. The National Weather Service’s GFS model sent the same system well south of the area. Such model disparities aren’t uncommon at such a range in time and reconciling such varied forecasts is always a challenge.

The European model and its ensemble model continue to suggest snow in that time frame, though the morning runs have tamped down the snow’s potential intensity. And the NWS GFS model continues to discount the system.

I’m inclined to suggest monitoring the Wed night/Thursday time frame. Anytime a solution, though not universal among various model, is presented over a period of days, it must be considered a potentially viable option. And there’s even a hint some lake moisture could get involved in such a system given the winds predicted at that time. So let’s continue to view the period as suspicious as we monitor newer model runs in the days ahead.

In the meantime–some solid advice would be prepare for the season’s coldest air to date and get the winter wardrobe ready!