A winter storm watch has been issued for a number of Chicago-area counties starting Tuesday evening as forecasters say confidence is growing that the region could be hit by not one, but two snow series.
The forecast remains fluid and snowfall projections are still uncertain as even a minor change in the storm’s track could cause dramatic changes, but a winter storm watch warns of up to 6 inches or more in some locations.
The watch begins Tuesday night for Grundy, Kankakee, Will, and central and southern Cook counties in Illinois, as well as Lake and Porter counties in northwest Indiana. It remains in effect until Thursday afternoon. Another watch is in effect for Newton and Jasper counties in northwestern Indiana, which warns of the possibility of snow totals greater than 8 inches.
Two rounds of snow are possible in parts of the Chicago area, with the first set expected to arrive Tuesday evening through Wednesday morning. The second would then take place from Wednesday evening to Thursday, with a possible break throughout the day on Wednesday.
National Weather Service forecasters say the break is making it increasingly difficult to project snowfall totals “since they ignore compaction during and between snow waves.” Areas along and southeast of Interstate 55 are currently expected to experience the greatest snowfall amounts.
At the start of the work week, temperatures are expected to warm, with highs reaching the 30s on Monday and then the 40s on Tuesday, according to forecast models.
On Tuesday afternoon, a significant change is expected to hit the region, with a weather system potentially bringing heavy rainfall to the region.
This system will begin with rain, but as temperatures begin to cool it will turn to snow, and according to forecast models, there could be severe impacts on movement from the storm, with mixed precipitation. , snow or ice, all of this is possible, depending on the temperatures. and location.
Adding some uncertainty to the equation, another wave of wintry weather could arrive right after this storm Wednesday night and Thursday. According to NWS, “confidence is growing” that this second round will hit the Chicago area, at least in part, Storm Team 5 meteorologists point out that any changes in the storm’s track could have a big impact on these projections.
Either way, a heavy snow cut is forecast for the northwest side of both systems, which could mean some suburbs in northwest Illinois could see little to no accumulation with either one. or the other system.
Travel conditions will likely be treacherous in areas that see snow with these two rounds, especially during morning and evening trips on Wednesday and Thursday.
The NBC 5 Storm team will continue to monitor weather systems as they develop, and the latest information can always be found on the NBC Chicago app.