Chicago’s uninterrupted 13-day string of below normal temps ends Wednesday with the arrival of the area’s mildest daytime high of the past 12 days.Temps are to peak at 36—a reading which would be substantially higher were it not for the snowpack in place here.
In a month dominated by arctic air, with an average December temperature more than 7-degrees below normal, ANY reprieve from the chill is welcome.
All by themselves, the past 13 days here have averaged more than 11-degrees below normal.
Gulf moisture is northbound and its arrival Wednesday night is to produce clouds followed by haze, some light fog and, eventually, some drizzle and patches of light rain as moisture levels increase over the coming 36 hours.
North toward Wisconsin, it’s possible some snow or ice pellets will occur Thursday night into Friday. A dusting to as much as an inch and a half of snow is possible there during that time frame.
Weekend storm potential being monitored Saturday night into Sunday; many questions in place at this early stage
Forecasters—this one included—continue reviewing model forecasts of a potential winter storm this weekend. The Saturday night/Sunday period appears most at risk from the weather system which is predicted to lift from Texas into the Ohio Valley between Friday and Sunday morning. It’s potentially a troublesome track for Chicago—one which, in the past, has been a snow producer here.
Complicating any forecast of this storm’s future behavior is the thermal structure of the atmosphere predicted for this weekend. While Chicago is to sit beneath the axis of this system’s most prolific precipitation, the form that moisture is to take will be driven by the temperatures within which it’s occurring. A more precise determination of just how temperatures will lay out this weekend is to come in the days ahead. Until then, those with travel plans would be well advised to monitor future forecasts.