Some parts of Arizona are expecting snow this week as a winter-like storm plunges temperatures up to 20 degrees below normal for this time of year.

National Weather Service (NWS) meteorologists flagged the incoming storm system on Wednesday morning, even though no winter weather warnings have been officially issued. There are still some uncertainties, but meteorologists are confident that a cold weather system will bring widespread showers across northern Arizona, with snow levels lowering on Friday, leading to hazardous travel conditions Friday and Saturday.

“Get ready to pull out those sweaters and jackets! Temperatures will drop 10-20 degrees below normal by Friday, leaving many locations to max out around 40 to 50 degrees. Warmer weather looks to return by next week though,” the NWS office in Flagstaff posted on X (formerly Twitter).

Another post said: “The first Winter-like storm will be impacting northern Arizona late this week and into the weekend. Much colder temperatures, gusty winds, and rain / high-elevation snow expected.”

NWS meteorologist Paige Konieczny told Newsweek that snowfall will remain primarily above 7,000 feet, with more impactful snowfall amounts expected in areas above 8,000 feet.

“This is pretty typical for this time of year,” she said. “We are heading into our winter season, so to get snow here in the middle of October is not completely out of the norm.”

However, the shifting temperatures will feel “dramatic,” Konieczny said, as the region has experienced above-normal temperatures the past few weeks.

“But those temperatures look to be rather short-lived once the storm system moves out of the area,” she said.

Normal temperatures are expected to return next week.

Counties expecting snowfall include Coconino, Apache, Navajo and northern Gila. Heavy snow will remain largely in mountainous areas, with up to 1.5 inches expected in more populated areas.

“The areas seeing higher [snow] levels are mountaintops,” Konieczny said, adding that up to 10 inches of snow is expected in higher elevations.

Since this is likely to be the first snowfall of the season, Konieczny said, there are travel concerns. Also, winds will be strong.

The Arizona forecast comes as other parts of the U.S. are expecting cold temperatures and, in Montana’s case, heavy snow. Earlier this week, freeze warnings and frost advisories were in place across much of the Central and Midwestern U.S., with some warnings in place along the East Coast as well.

“Cooler temperatures, rain and light snow are forecast for the Midwest and portions of the Eastern U.S. early this week as a cold front progresses through,” the NWS said.

On Wednesday morning, some frost advisories and freeze warnings remained in some states, including Arkansas, Alabama, Georgia, South Carolina and North Carolina, as well as some parts of the Eastern U.S.