A punchy early-season winter storm brought wintry conditions to parts of the western U.S. on Friday morning.

In northern Arizona, winter weather swept through, impacting Flagstaff and surrounding areas. Snowfall blanketed Mount Humphreys and Arizona Snowbowl, with up to 12 inches expected in higher elevations. Hail contributed to slushy road conditions, prompting a winter weather advisory for parts of northeastern Arizona.

The average first day for measurable snow in Flagstaff is around November 11.

Colorado also felt the storm's effects. While covering the event in Silverton, Co., weather reporter Jonathan Petramala encountered a traffic jam caused by a vehicle that slid off the road, likely unprepared for the slick conditions. Up to 2 feet of snow could fall on the highest peaks through Sunday.

Since then, temperatures in Arizona have dropped significantly. In Flagstaff, Ariz., and other nearby higher-elevation areas, temperatures will likely dip into the mid- to upper 20s—colder than usual for mid-October.

Conditions are expected to improve by Sunday.