Storms are targeting both coasts on Sunday, with rain and snow slamming the Northeast and the Pacific Northwest.
On the East Coast, a rainstorm soaked Philadelphia, New York and Boston on Sunday.
Several inches of snow are piling up Sunday into Monday from the Adirondacks in New York to the White Mountains of New Hampshire and Maine, forecasts show.
Six to 12 inches of snow is forecast for northern New England.
Winter weather alerts have been posted for much of Vermont, New Hampshire and Maine through Monday morning. The steady snow is forecast to taper off by Monday afternoon.
Meanwhile, a series of storms are forecast to bombard the Northwest over the next several days.
MORE: What every motorist needs to know about driving in snowFlood watches are in effect in Seattle and Portland, Oregon. Another 3 to 6 inches of rain is forecast for western Washington and Oregon.
Winter storm warnings have been issued in Jackson, Wyoming; Park City, Utah, and Aspen, Colorado.
Parts of the Northwest and Rocky Mountain ranges could see an additional 6 to 12 inches of snow through midweek.
High wind warnings are in effect from Montana to Colorado, where wind gusts could reach 60 mph, knocking out power. In some areas, the combination of mountain snow and strong winds could cause whiteout conditions.
There's also an increased risk of avalanches for parts of the northern Cascades in Oregon and Washington due to the recent heavy snow and the rapidly warming temperatures.