The National Weather Service has issued a winter storm watch for most of the Chicago area and parts of northwest Indiana, but what exactly does that entail?
The issue at play is uncertainty in the track of the storm, with some forecast models indicating that it could make a direct hit on the city of Chicago and surrounding suburbs, while others suggest that it could slide to the south and bring more snow and icy conditions to central Illinois and Indiana.
While we don’t know where exactly the storm will track, there are a variety of weather threats that could be posed by the system as it moves through. Here’s what we know so far:
Early in Storm – Rain and Flooding
Rain will begin to move into the Chicago area on Wednesday afternoon and into the evening, and it is expected to be heavy at times, with some locations seeing 1-to-2 inches of rain.
That rain, coupled with rapidly-melting snow, could cause flooding in area streams and rivers, and if the warm weather causes ice jams to shift or break up, that could exacerbate the situation even further.
Late Wednesday and Into Thursday – Icy Wintry Mix
Winds are going to shift out of the north during the storm, causing temperatures to rapidly fall and leading to freezing rain and sleet late Wednesday and into Thursday morning.
That changeover will happen from the north to the south, meaning that some locations could potentially see more than one-tenth of an inch of ice buildup before the precipitation changes to snow.
Thursday – Snow and Wind
Speaking of the snow, that part of the storm will be the most heavily-impacted by the storm track. If the system moves in a more northerly direction toward Chicago, then it could draw in moisture from Lake Michigan, which could cause heavier snowfall totals across a wide swath of northern Illinois.
If it tracks more to the south, then areas in the far southern suburbs, as well as in central Illinois and Indiana, could see the heavier accumulations.
The other part of the equation is the wind, which could cause blowing and drifting snow in some locations. That could cause serious travel headaches on area roadways, which will already be dealing with the threat of patchy black ice from the earlier sleet and freezing rain.
Other Potential Issues
Travel issues are going to be the main point of concern late Wednesday and into Thursday, with both the morning and evening commutes potentially impacted by wintry weather. Slick conditions could develop Thursday morning because of the ice, and by afternoon heavy snow and gusty winds could cause visibility problems on area roadways.
In addition to the travel problems, areas along Lake Michigan could see some serious issues, as the northerly winds will cause large waves and lakeshore flooding in some areas.
What’s more, freezing spray could also become an issue, coating areas along the lakefront with ice before the system begins to move out of the region.