Mother Nature was apparently trying to cram as many seasons as possible into one day Tuesday, as an arctic cold front and strong low pressure system brought thunderstorms with hail, very strong winds, unseasonable warmth, bitterly cold temperatures, and blizzard conditions to portions of the region, and all within a matter of hours of each other!
Southerly winds ahead of the arctic front provided the region with unseasonably mild temperatures with readings around 20 degrees above average for late January. The following map was created by NOAA Midwestern Regional Climate Center and depicts the temperatures and winds across the region at noon Tuesday as the front was moving across Illinois.
As the arctic front moved through the Chicago metropolitan area Tuesday afternoon scattered thunderstorms developed with some areas even getting some pea sized hail out of the stronger storms. The most dramatic part of the frontal passage was the tremendous temperature drop for such a short time period. After peaking near 50 degrees, temperatures fell around 40 degrees in a 6 hour period, with much of that fall confined to the first hour or so after the front passed. NOAA Midwestern Regional Climate Center also created the following map, depicting just how large the temperature fall was across the region.
Temperatures by Tuesday evening had fallen into the single digits across northern Illinois and northwest Indiana, which were punctuated by 50 to 60 mph winds which sent wind chills into the 20 to 35 degrees below zero range. As if the bitter cold wasn’t enough, there was also heavy snow fall for a few hours across northeast Illinois and northwest Indiana. While snowfall totals were only an inch or two, the 50 mph winds created blizzard conditions and made travel nearly impossible for a time Tuesday evening.