An Ice storm warning (scarlet-shaded area on the headlined map) for freezing rain mixed with sleet and snow is in effect until mid-morning for a good portion of the Chicago area along and north of Interstate-80. At the same time, additional snow accumulation is expected today and tonight in northern counties bordering Wisconsin. A Wind Advisory kicks-in beginning at 2PM CST this Tuesday afternoon continuing well past midnight tonight.
Due to a glaze covering a good portion of our area, extremely dangerous conditions for outdoor activities and travel will exist area-wide. Almost a half-inch ice accretion has occurred (Midway reported a total ice accretion of 0.44-inch). Temperatures will hover around 32-degrees this morning, then fall into the 20s this afternoon, so not much melting will go on – thus the afternoon/evening commute will also be slowed.
The center of an intensifying low pressure system will move off to the northeast through Lower Michigan today into Ontario, Canada later tonight. As the storm center pulls away, strengthening west to northwest winds eventually gusting 40 to 50 mph or higher will direct much colder air into our area, changing all precipitation to snow showers and potentially causing widespread ice-laden tree damage and subsequent power outages later today and tonight. Greatest additional snow accumulations of 2 to 4-inches will occur in northern counties adjacent to Wisconsin even into the overnight hours tonight with much lesser amounts the farther south you go.