The Pacific Northwest and western Rockies should brace for a dramatic start to the winter, with bitter cold and significant snowfalls, while the eastern United States will have less of both, according to a long-term forecast by Accuweather.

The private forecasting firm also warned that the upper Midwest, including Chicago, could face heavy snow around the holidays, in a forecast released on Wednesday, less than a week after a rare October snowstorm hit the central Rocky Mountain region, stranding motorists, killing livestock, and downing trees in parts of Wyoming and South Dakota.

Warmer weather is forecast for Oregon and Washington, with colder conditions to the east in Wyoming and Montana. Those colder conditions will bring more snow, but forecasters are less certain of where the temperature differential will occur.

"There will be a big contrast, but where that dividing line is hard to say," said meteorologist Paul Pastelok.

California, meanwhile, may get some drought relief from significant precipitation in December and January

"This can definitely alleviate some drought issues," said Pastelok. "We're going to fill those reservoirs up a little bit."

The firm projects a mild winter for much of the northeast, with snow likely holding off until late in the season - especially in coastal areas, which last year experienced several major storms. Chances for an early snowfall increase in northern New York and western New England.

The southeast may break high temperature records in December. Those high temperatures will bring with them the potential for severe storms and flooding in December and February along the central and western Gulf Coasts.

The 2012-2013 winter ranked as the 20th warmest since scientists began collecting records in 1895. It followed the fourth warmest on record, according to the National Oceanic and Atmospheric Administration.