Snowflakes flew for the first time this season in several states across the Upper Midwest, where the first big taste of winter arrived to end the week.

More than a half-foot of snow fell in parts of Wisconsin, and Chicago's O'Hare International Airport received its first Halloween snow accumulation on record. This snowfall is part of a system that is expected to move into the Ohio Valley and Appalachians, dumping several inches of snow in some areas while dropping temperatures for millions.

(MORE: See If You'll Be Affected By This Arctic Blast)

At the top of this page is a collection of images from areas that have seen snowfall so far, and be sure to check back frequently as new photos are added to the gallery all weekend.