A trio of storms will hit the US with "everything but the kitchen sink" in a three-day of heavy snow, blizzards and floods.
Storm Ember will smash the east coast today before Storm Finn and a third unnamed tempest join forces for a brutal winter assault.
Swaths of America are on alert for heavy snow, crippling blizzards, thunderstorms, freezing fog and Arctic gales.
The National Weather Service (NOAA) has sounded the alarm for a "major" and "rapidly strengthening" winter storm.
The National Weather Service (NOAA) has sounded the alarm for a ‘major’ and ‘rapidly strengthening’ winter storm
The Weather Channel
A spokesperson said: "There are three storm systems that are and/or will be impacting the [United States] over the next few days.
"A major winter storm will produce additional heavy snow for Northeast and Central Appalachians, and a rapidly strengthening storm will lead to widespread, significant impacts over much of the central US."
An "intense" storm will sweep eastwards from the west coast through the coming days, according to independent weather forecasters.
Those in the firing line are warned to prepare for "significant impacts" from heavy rai, snow and powerful gales.
The first storm was due to pick up last night before leading a trio of tempests across the United states through the week.
Eastern and Central states will be hit by the peak of the attack towards mid-week, according to The Weather Channel.
Meteorologist Chris Dolce said: "An intense storm will track from the West into the central and eastern states early next week with significant impacts possible from snow, wind, heavy rain and severe weather.
"The widespread storm will deliver everything but the kitchen sink in terms of impacts as it carves a path from the west into the central and eastern states.
"Peak impacts in the central and eastern states will be Monday and Tuesday, lingering into Wednesday for some, and low pressure will intensify as it tracks from the Southern Plains toward the Great Lakes."
Storm Ember unleashed the first bout of snow, rain and winds towards the end of the weekend, with Storm Finn threatening snow, the Weather Channel said.
Impacts to those living in the worst-hit regions will ‘cover a full spectrum’, although the exact track of the storms is still uncertain, it added.
A Spokesman said: "Ember is producing snow from parts of New York and Pennsylvania to New England. Some coastal areas are seeing rain or a mix of rain and snow.
"The snowy side of this storm has been named Winter Storm Finn by The Weather Channel."
Snow and rain is set to move across the country
The Weather Channel
The NOAA’s State "warnings" map highlights the risk of winter storms in central and southwestern regions, with more widespread general storm alerts and separate warnings for high winds.
Stormy weather systems will pull in a plume of cold air putting huge swaths of the States at risk of heavy snow.
Strong winds will whip up blizzards across the Midwest and the Plains, while heavy rain hits the milder south.
Jim Dale, US weather correspondent and meteorologist for British Weather Services, said: "There is going to be a pool of cold air originating from Canada that will move into the northeast in the wake of these storms.
"This is going to bring the risk of heavy snow to parts, especially over the hills and mountainous regions and heavy rain elsewhere.
"The first storm comes in from the Gulf of Mexico, and then the very volatile weather is likely to continue into the middle of the week."