Chicago braces for a one-two punch from the most powerful storm of the young 2012-13 meteorological winter season to date. The system appears likely to unleash more moisture here than has fallen at any time in five months. Its snows—predicted by computer models as likely to end up in the two to four inch range are to be the heaviest in 10 months and the first measurable quantities of snow to fall this season.
While 2 to 4 inches of snow are likely in Chicago, some estimates suggest as much as a half foot of snow could fall over portions of the area and significantly heavier totals are likely to fall to the north, including the foot or more of snow which may come down in sections of Wisconsin.
With 2012 year-to-date precipitation here in the metro area, down more than 10 inches and running at only 70 per cent normal, prospects for a good soaking rain followed by accumulating snow aren’t all bad. But it’s at that point any good news with this system ends.
Blizzard conditions are likely to shut down travel across sections of Wisconsin as well as portions of northwest and north central Illinois Thursday and Thursday night west into Iowa and Nebraska. This is the region likely to see the heaviest snowfall.
The treacherous travel may extend beyond that heavy snow band. The lack of snow to date over a wide swath of the Midwest, including Chicago, means any residual ice-detering road chemicals simply aren't there as this winter storm moves into the area with its snows. This could lead to especially icy road surfaces producing hazardous travel conditions.
Storm’s gargantuan wind field to accompany transition to snow and to include 50+ mph gusts later Thursday into Thursday night and Friday
The storm is to subject the Chicago area to punishing winds, particularly late Thursday and Thursday night, when 50 mph or stronger gusts may deliver that period's snowfall horizontally. The snow threat is to commence with a temperature drop predicted to follow a mid-afternoon cold frontal passage. The wind-driven snows may occur ominously close to the evening rush hour amid falling temperatures.
Wind-driven late Thursday snow to fall measurably for the first time this season over a 6 to 10 hour span of time
Forecasts of how much snow is predicted to fall will continue to be monitored as the system moves ever closer to our area. The best thinking at this stage of the storm's development is that rains Thursday morning and early afternoon will begin shifting to snow mid afternoon, leading to a six to ten hour period in which snow falls here, possibly heavy at times.
Quiet weekend, but second potential snow system to lift into the Midwest next week
Details remain fuzzy this far in advance—but a second storm system may lift into the Midwest next week. We’ll continue updates on that possibility in the days to come.