Winter Weather to Sweep Across US With Rain and Snow

The weather system will freeze some cities and inundate others with floods.

— -- Winter weather is sweeping across the nation this week, freezing cities, burying others in snow and inundating some with floods.

As much as 56 inches of snow have piled up in the Sierra Nevada mountain range in the Northwest region so far this week, due to a persistent plume of jet stream off the Pacific Northwest. That jet stream energy will stretch across the country, over to the South and East regions, according to ABC News meteorologists.

A series of storms are forecast to ride the jet stream, leaving behind a trail of snow from California to Alabama and north into New York. As of Thursday, parts of 40 states are under winter weather alerts.

A storm is expected to coat the mid-Atlantic and southern New England with a couple of inches of snow, in most locations, before the end of the week.

Another weather system will track further south Friday and Saturday, unloading snow and ice. Southern cities like Birmingham, Atlanta and Raleigh could see one to three inches of snow, according to ABC News meteorologists. This storm will strengthen off the southeast coast and produce even more snow for the Carolinas on Saturday.

"Take a look at the wide area of snow forecast," ABC News senior meteorologist Max Golembo said. "Anywhere from Ohio Valley to the Deep South and in to the Northeast -– all will be getting snow.

Meanwhile, forecasts indicate a powerful "atmospheric river" event will take aim at California this weekend and into next week with heavy precipitation, high snow levels and soils that are already drenched from recent storms.

The brunt of the storm is expected to arrive Sunday and Monday, threatening floods that the National Weather Service said may be the worst since December 2005.

"If you think the west is done with the rain and snow, guess again," Golembo said.