Winter Storm Warning for 8 States As Severe Thunderstorms Expected

Winter weather warnings are in place for eight states as meteorologists predicted a "deep storm" will produce heavy rain over the mid-Atlantic and the Appalachians, with snow expected to follow for parts of the Great Lakes.

The National Weather Service (NWS) has issued snow and strong wind alerts for parts of Indiana, Maryland, Michigan, New York, Ohio, Pennsylvania and the Virginias, warning of difficult travel conditions, near-blizzard conditions in some places, and falling trees that could cause power outages.

In its latest forecast, the NWS said there was a slight risk of excessive rainfall over parts of the mid-Atlantic coast and New England through to Tuesday morning that "will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable."

It added that the weather front would produce "showers and thunderstorms" over the region before moving into Canada later on Tuesday.

In parts of West Virginia, between five and 11 inches of snow are expected, with wind gusts of up to 35 mph, through to 10 a.m. ET on Tuesday. Western Greenbrier County in Virginia will see four to eight inches—with locally higher amounts possible—in the same period, as well as winds of up to 45 mph.

Snow accumulations of between six and 10 inches are possible on western slopes of Maryland's part of the Appalachians, with three to six inches on eastern slopes, and the heaviest snowfall anticipated to develop on Monday between 1 and 4 p.m. ET.

The NWS said that, in the wake of the storm, an eastward front bringing cold air is expected to bring lake-effect snow to parts of the Great Lakes and upslope regions of the northern and central Appalachians, with the heaviest snowfall over the central part of the mountain range and southeast from Lake Michigan, in Michigan and Indiana.

"Additionally, another area of the heaviest snow will be along the central and eastern shore of Lake Erie in Ohio and New York State," it said.

Lake-effect snow is a phenomenon in which cold air from Canada picks up moisture from large bodies of water to produce precipitation.

New York's Chautauqua County is set to see heavy snow, with accumulations of seven to 10 inches and "much lower amounts" near Lake Erie. In Pennsylvania, higher elevations in Fayette and Westmoreland counties will see up to a foot of snow and wind gusts as high as 40 mph, with visibility dropping below a quarter of a mile due to blowing snow.

Up to 11 inches of snow could be seen in parts of Ohio, while as much as eight inches could accumulate in counties in Indiana to the east of Lake Michigan. Lake effect snow up to eight inches, with locally higher amounts, is expected in parts of Michigan bordering the lake.

The region has already seen some lake-effect snow, and recently faced another bout of snow brought on by an Alberta Clipper system moving cold air down from Canada.

Meanwhile, Western states have been subjected to a "prolific series" of atmospheric river storms from the Pacific, having experienced the effects of a similar weather front last winter. The NWS said most of the Pacific Northwest would see rain and some snow at higher elevations from Monday as another weather front moves onshore.