US Winter Storm: A massive winter storm is barreling across the United States and millions of Americans are hunkering down as snow, ice and biting cold spread from coast to coast. Fresh forecast maps on Saturday showed just how far-reaching the storm is expected to be, with conditions likely to worsen across large parts of the country through the weekend.

The storm is on track to travel more than 2,300 miles and affect at least 35 states. So far, 17 states and Washington, D.C., have declared states of emergency, while nine states have activated their National Guard units. Forecasters say nearly half of the US population could be impacted in some way, with close to 150 million people under winter weather alerts through Sunday.

Snow in the North, dangerous ice in the South

A wide stretch of the country, from Oklahoma City to Boston, is expected to see heavy snowfall. In the Northeast, many areas could end up with more than a foot of snow. Places closer to the heart of the storm, including parts of Kentucky and Virginia, may see totals climb as high as two feet between Saturday and Monday.

Major cities such as New York City, Boston and Oklahoma City are forecast to receive anywhere from 12 to 18 inches, while the outer edges of the system could still bring 1 to 6 inches to broad regions.

However, the bigger worry in the South is ice. Forecasts show a dangerous mix of freezing rain and snow from east Texas through Tennessee and into parts of Georgia and Virginia. Officials warn that ice can be even more disruptive than snow, snapping power lines, knocking out electricity and making roads nearly impossible to navigate.

Some areas across Texas, Georgia, Arkansas, Mississippi, Alabama and Tennessee could see up to three-quarters of an inch of ice, with isolated spots approaching an inch.

Power outages hit many

Power outages are already mounting. According to poweroutage.us, more than 50,000 people woke up without electricity on Saturday. Texas alone accounted for nearly 18,000 outages, with thousands more reported in Minnesota, California, Arkansas, Michigan, Pennsylvania, Mississippi and the Virgin Islands.

On top of snow and ice, forecasters are also warning about frigid temperatures, strong winds and dangerously low wind chills.

The National Weather Service said the most severe impacts are likely where freezing rain tops half an inch. It has urged residents to avoid unnecessary travel, prepare for outages and stay tuned to local advisories as the storm continues its march across the country.