A powerful winter storm has been hammering parts of the western United States with heavy snow and will progress to the east, bringing more snow and wind to the midwest, Ohio River Valley and northeast this weekend.

This Pacific storm came onshore late on Wednesday and Thursday and brought heavy snow to Sierra as well as flooding rains to many parts of California.

At least six deaths are being blamed on the storm along with 13 rescues only in the state of California.

The higher elevations of the Sierra Nevada Mountains received up to a metre of snow. Heavy snowfall, along with the gusty winds, made travel nearly impossible on the roads that cross many of the mountain passes.

As the storm crossed the Rockies, the popular Steamboat Ski Resort in Colorado picked up 63cm of snow.

On Saturday morning, the storm had entered the Central Plains and was forecast to strengthen and continue to bring widespread snow, damaging winds and severe storms to most of the Central and Eastern US.

Winter weather watches and warnings have already been issued from Kansas to Maine, with over 110 million now in the path of the storm.

The storm will rapidly strengthen as it moves east on Saturday and then turns northeast on Sunday.

Across the Gulf coast on Saturday, severe thunderstorms are expected to bring gusty damaging winds as well as the possibility of a few tornadoes to the states of Louisiana, Mississippi, Alabama, Florida and Georgia.

On the north side of the storm, heavy snow and strong winds will be widespread from parts of the Midwest into the Northeast on Saturday. Some areas may begin to see some sleet and freezing rain, particularly in places where the temperatures hover near the freezing mark, making travel on the highways dangerous.

On Sunday, it will be the Northeast and the Canadian province of New Brunswick that will receive the brunt of the storm.

Some of the heaviest snowfalls could be seen across the higher elevations of New York state, Vermont, New Hampshire and Maine, with some locations receiving over 66cm.

Sleet and freezing rain are possible along coastal and southern New England.

And if all those winter conditions were not bad enough, some moderate coastal flooding is possible in Massachusetts, especially during high tide. In Boston Harbor, a metre of water could pile up because of the northeast winds pushing onshore.

At the airports, the storm has already caused widespread delays and cancellations. On Friday, almost 5,000 flights were delayed. And even before the day began on Saturday, over 1,100 flights were already scheduled to be cancelled.

Snow across the Northeast will gradually ease on Monday, but the winds will continue to be gusty. Combine those winds with the arctic air mass that will be moving in behind the storm and many could experience wind chills in the northeast as low as -40 degrees Celcius.

Another winter storm will be making its way out of the Pacific this weekend and will bring further wintry mess next week to many of the same states currently affected.