Update 7PM CST…
Indications are that the freezing rain/sleet/snow combination is spreading across the northernmost portions of Illinois into southeast Wisconsin, so the Winter Weather Advisory (purple-shaded areas on highlighted map) now includes all of northern Illinois into northern Indiana. The wintry precipitation will diminish later tonight with the Advisory ending area-wide by 6AM CST Monday morning. Travelers should continue to take precautions and prepare for slick roads and very dangerous driving conditions tonight.
Update 2PM CST…
The Winter Weather Advisory (purple-shaded counties in highlighted map) has been extended farther north to include all northern Illinois counties except those adjacent to the Illinois-Wisconsin state line (where roads/highways could also become slick in spots), as well as all counties in northern Indiana. A combination of freezing rain/sleet and snow will make for icy roads/highways and dangerous/slow driving conditions this Sunday afternoon into the overnight hours.
A Winter Weather Advisory (purple-shaded area on the highlighted map) for a combination of snow/sleet and freezing rain is in effect this afternoon and tonight into early Monday for the portion of northeast Illinois and northwest Indiana south of Interstate-80. North of Interstate-80 the precipitation type is expected to be more snow, where some sleet could be mixed in over that portion of our area. By the time precipitation ends from west to east later tonight/early Monday there looks to be 1 to 2-inches additional snow cover area-wide.
Widespread slippery roads are likely later this afternoon and evening as the wintry mix of precipitation spreads in from the west/develops over the area. Note on the map below, the Winter Weather Advisories extend to our west, south and east, so travel in those directions will be especially dangerous. This weather will be associated with a warm front moving east out of Iowa across Illinois into Indiana, followed by a weak cold front early Monday.