(CNN) -- Blizzard conditions whipped through Colorado on Friday, closing some 70 miles of interstate highway as heavy snow blanketed the region, according to the state's Department of Transportation.

Officials reported a total of 600 flight cancellations at Denver International Airport, while Southwest Airlines canceled all inbound flights to Denver until 1 p.m. local time. Denver's airport -- which was reporting 5 inches of snow as of 10:45 a.m. -- deals with an average of 1,700 flights daily, according to airport spokeswoman Jenny Schiavone.

Light snow started falling in Denver Thursday as residents across the state braced for the storm.

Parts of the region could be plowing out from under 2 feet of snow and higher drifts by Saturday, when conditions are expected to gradually taper off.

The National Weather Service issued a winter storm warning starting Thursday evening along the Interstate 25 corridor, including the city of Denver.

Most areas east of the city are under a blizzard warning, as snowfall rates of up to 2 inches per hour were expected.

The warnings will remain in effect into late Friday evening.

The airport has nearly 300 pieces of snow equipment and a team of approximately 500 trained snow removal personnel who plan to work throughout the storm.

An avalanche watch that had been posted for the Front Range and Sangre de Cristo mountains was expected to expire on Friday. But rapid heavy snow on top of the currently weak snowpack structure could also quickly raise the avalanche danger, according to The Colorado Avalanche Information Center website.

The storm will be slow moving, so a prolonged period of snow will occur through early Saturday, according to the National Weather Service.

With winds gusting 40 mph or higher, blowing snow will make visibility at times near zero and travel on roads could be treacherous, if not impossible.

A number of school districts in the Denver Metro area announced closures on their websites, including Denver Public Schools, Jefferson County Public Schools and Douglas County Schools.

High temperatures are expected to remain in the 30s into early next week.

CNN's Adam Shivers contributed to this report