FLAGSTAFF, Ariz. (AP) — Bitter cold, rain and snow blew across much of the Southwest U.S. on Tuesday, closing stretches of interstate and state highways in northern Arizona where as much as a foot (30 centimeters) of snow was possible and even colder weather on the way.

A winter storm warning remains in effect into Wednesday evening for much of northern Arizona and New Mexico, the National Weather Service said.

A 40-mile (64-kilometer) stretch of northbound Interstate 17 from Lake Montezuma north to Flagstaff was closed Tuesday evening. A short stretch of I-40 near Winslow also was shut down as the powerful cold front continued to move east.

It’s likely to produce snowfall rates of 1 to 2 inches (2.5 to 5 cm) per hour in parts of northern Arizona including Flagstaff, the weather service said late Tuesday.

“The combination of heavy snow and blowing snow will reduce visibility on area roadways, leading to dangerous driving conditions,” the weather service in Flagstaff warned.

Overnight lows below zero Fahrenheit (below -17 Celsius) were forecast in the Sierra along the California-Nevada line, with single digits in parts of Arizona, the National Weather Service said late Tuesday.

“Winter storm impacts will focus across northeast New Mexico Wednesday afternoon and evening before the system exits Wednesday night, with near blizzard conditions possible,” the weather service in Albuquerque said late Tuesday.

The service in Reno warned “it will be downright dangerous in exposed areas of the high Sierra” early Wednesday with wind chills of -20 to -30 degrees Fahrenheit (-29 to -34 Celsius).

Winds gusting up to 88 mph (141 kph) were recorded early Tuesday in the central Sierra at Mammoth Mountain south of Yosemite National Park, the service said.