Temperatures will begin to plummet from the Ohio Valley to the interior Northeast on Tuesday and Tuesday night, then to coastal areas on Wednesday.
"Some of the coldest air in decades will pour in across the Northern Plains, Midwest and Great Lakes with windchills in the -40 to -50 degree range and air temperatures below zero for several days", Fox News Senior Meterologist Janice Dean said Monday.
Snow, sleet, and freezing rain could mix in as far south as the metro for a brief period of time on Tuesday, but we don't expect much with little to no accumulation possible. It is VERY important that you are dressing warm and limiting time outdoors as temperatures and wind chill will be dangerously cold.
But Monday's snow is just a precursor to what's in store for IL starting Tuesday. Lows of zero to minus 5 and highs of zero to 5 degrees are forecast for Thursday.
The National Weather Service has issued a number wind chill warnings, watches, and advisories across the Midwest. Wind chills in northern IL could fall to 55 degrees below zero, which the National Weather Service called "possibly life threatening". The wind chill temperature, which is a measure of what the air fees like when wind is taken into account, will fall as low as minus-65 in the Upper Midwest. Many locations are predicted to challenge their coldest high temperatures for January 30 on Wednesday, and a number of record lows may be set Wednesday and Thursday mornings. Temperatures will also be comfortable with highs topping out in the low to middle 50s.
Temperatures are forecast to inch up to a daytime high of about minus 14 on Wednesday - the first subzero high temperature in five years and the coldest winter high ever recorded in Chicago - before dipping, again, to about minus 21 overnight.
Interim city health Commissioner Mary Beth Haller declared a "Code Blue" emergency from Tuesday night through Friday morning. They encourage shutting off water to outside faucets and allowing a trickle of water to flow from a basement faucet, because moving water is less likely to freeze. Public works crews were spending Monday pretreating roads in Atlanta, which has a busy week ahead of the Super Bowl on Sunday.
"A couple inches of snow can fall in Jackson, Mississippi; Birmingham, Alabama; and Chattanooga, Tennessee", AccuWeather meteorologist Kristina Pydynowski said. They are expected to return to normal by Sunday.