CHICAGO – As much as 4.5 inches of snow has fallen across the Chicago area, the heaviest of the season to date. O’Hare’s 3.5 inches is the heaviest snow to occur in the city since 5.2 inches fell just under a year ago on Feb. 2 – and it won’t be the last as we enter a far more active late winter weather pattern.

Along with the snow, Chicago logged its 15th of January’s opening 25 days with no sun, and the day produced a 29th consecutive daily temp surplus. The snow is winding down to sporadic flurries which are to persist at times into Thursday.

Friday sees a very windy cold front coming onto the scene bringing a new round of snow showers, but it’s two systems as we cycle into markedly colder air this weekend into next week.

That seems to line up as potential new “system snow” producers.

The first of the two is to be produced by a disturbance currently winding its way across the northern Gulf of Alaska and southern Canada. That disturbance, embedded in a powerful jet stream, will dive into the Rockies and to Texas in the coming days, at which point it turns northeast into the Midwest.

Snow could fly as early as Saturday afternoon in Chicago and continue that night into Sunday.

A second system further out in time and therefore more problematic, but something which has shown up in multiple models run for days, could ride into or close to our area next Tuesday night into Wednesday.

It could mean still more snow for Chicago.

A major shift to cold arctic air continues to be indicated by the whole constellation of computer models involved in our forecast preparation process. While temps this week, though colder than last on a weekly average basis, yet still likely to post a modest 2 degree surplus (compared to last week’s 12 degree surplus), next week’s average weekly temps could plunge nearly 16 degrees, averaging 14 degrees below normal if current forecast trends verify.

That translates to daytime highs only in the teens a number of days next week and nighttime lows in single digits. It’s the cold air that has, except for the arctic blast in December, avoided our area over the past month.


TONIGHT: Light snow diminishes to occasional flurries, breezy and colder. Some more substantial lake effect snow showers are likely to sweep into part of northwest Indiana—especially from Porter and La Porte counties into southwest Lower Michigan. Low 24.

THURSDAY: Cloudy and seasonably cold. Passing flurries at times. High 33.

THURSDAY NIGHT: Clouds persist, colder. Some flurries mainly early. Low 21—some teens possible inland.

FRIDAY: Snow showers develop, becoming quite windy with gusts building to 40 mph. Modest accumulations possible ranging mostly from a dusting to an inch.

SATURDAY: Cloudy, colder. Good chance of snow developing in the afternoon, continuing at night. Snow may accumulate and this system will have to be monitor. Breezy with northeast winds locking in. High Saturday 28. Low Saturday night 20.

SUNDAY: Snow flurries, windy and colder. High 25—but falling during the day.

MONDAY: Mostly cloudy and colder. Chance of light snow or flurries. High 25.

TUESDAY through WEDNESDAY: Cloudy, cold and breezy. Chance of snow later in the day—but more likely at night and into Wednesday. High Tuesday 18. Wednesday’s high 17.