Latest snow storm forecast maps show fresh predictions for where winter weather will hit hardest

As millions of Americans hunker down for a massive winter storm sweeping the country, new maps are offering updated forecasts of snow and ice accumulations. 

More than 200 million people are under winter storm threats. The storm is predicted to travel over 2,300 miles across 35 states. Seventeen states and Washington, D.C., have declared states of emergency, and nine states have activated their National Guards. 

"A significant, long-duration winter storm will bring widespread heavy snow, sleet, and freezing rain from the Southern Rockies to New England through Monday," the National Weather Service says. "Widespread travel disruptions, prolonged power outages, and vast tree damage is likely."

Forecasters also warned of frigid temperatures, gusty winds and dangerous wind chills.

Areas at the center of the storm, including parts of Kentucky and Virginia, could see as much as two feet of snow between Saturday and Monday. Major cities including New York City, Boston and Oklahoma City could see between 12 and 18 inches of snow. The outer bands of the storm could bring between 1 and 6 inches to large swaths of the country.   

Maps show winter storm forecast

This map shows the storm system spanning from New Mexico and Texas to the Northeast, with parts of many states forecast to see 12 inches of snow or more.

The southern part of the country will see accumulations of both ice and snow. Ice accumulations can be more dangerous than snow, officials warned. The weight of ice on power lines is more likely to cause outages. It is also harder to clear than snow and can make for dangerous driving conditions. 

Ice accumulations of up to 1 inch are forecast for spots of the South. Parts of Texas, Georgia, Arkansas, Mississippi, Alabama and Tennessee might see up to .75 of an inch of ice. Areas along the outer bands of the storm are expected to see up to a half inch.

"Catastrophic impacts are expected where freezing rain amounts exceed a half inch, with over one inch totals possible in parts of northern Louisiana, central and northern Mississippi, southern Tennessee, and the southern Appalachians," the National Weather Service says.   

Freezing temperatures are compounding the storm's effects. Snow that melts can quickly turn to ice. Wind chills are quickly bringing the mercury into the negatives. 

"If it gets out ahead of us and it becomes snow packed, solid sheets of ice, we get down into single digits — not a lot you can do," Justin Pierce, a plow driver with the Nashville Department of Transportation, told "CBS Saturday Morning." 

Over 43 million people are under an extreme cold warning, which means temperatures or wind chills are forecast to fall below 5 degrees Fahrenheit over the next 12 to 24 hours, according to the National Weather Service. Over 22 million people are under an extreme cold watch, which means those conditions are expected in the next 24 to 48 hours. 

More than 146 million people are under a cold weather advisory, which the weather service said is issued when either temperatures or wind chills are expected to fall to or below 15 degrees but remain about 5 degrees Fahrenheit. 

"In the wake of the storm, communities from the Southern Plains to the Northeast will contend with bitterly cold temperatures and dangerously cold wind chills," the weather service says. "This will cause prolonged hazardous travel and infrastructure impacts."