What is a Wind Chill Advisory?

Yet another arctic blast is in the forecast for Northern Illinois and Southern Wisconsin as we head into this weekend and early next week. The thing about this blast of cold is that it may be even colder than our previous arctic air experience earlier this week. A departing low pressure system is turning our winds northwesterly this evening, and that is going to allow arctic air to plunge into the area beginning on Saturday night as lows fall to near 0°. High temperatures on Sunday are only going to rebound to near 2° with some areas possibly remaining below zero. The coldest time will be Sunday night as temperatures are expected to fall as low as -5° to -10°, especially in outlying areas away from city centers.

During these frigid times, we will have blustery winds 10-20mph out of the west and northwest. That will lead to wind chill temperatures well below zero. In fact, we could see wind chills late Sunday night into Monday morning in the -20° to -30° range. The heart of the arctic air will likely remain in Minnesota, Northern Wisconsin, and Eastern North Dakota, but our wind chills will likely lead to the issuance of a Wind Chill Advisory or Wind Chill Warning (see graphic above for information on those and what leads to their issuance).

If issued, it would be the first time this season we see that weather headline for the Stateline. While we've experienced bitterly cold temperatures, we have not had the wind component at the same time, which explains why we haven't seen Wind Chill Advisories or Wind Chill Warnings yet this winter. Temperatures will stay in the single digits on Monday with subzero lows Monday night again expected.

Here is what the wind chill temperatures will look like for the next 48 hours. Notice the downward trend thru Saturday and Sunday with minimum wind chills likely approaching -30°, especially from Rockford north and west.