March may not come in like a lion everywhere across the nation, but winter will roar during the first several days of the month and impact more than 100 million people.

Snow will expand from the northern Rockies and central Plains to portions of the Midwest this weekend, reaching the Northeast early next week.

The adverse winter conditions will develop Friday into Saturday over the Plains and is forecast to shift slowly eastward Sunday and Monday.

People traveling by road or airways should expect major long-lasting delays as this area of snow expands eastward and crawls along.

For a time, the snow or a wintry mix will impact areas between the I-70 and I-90 corridors over the Rockies and Plains and the I-64 to I-90 corridors in the Midwest and East. From the Midwest to the Northeast, portions of I-80 could close for a time due to a very heavy snowfall rate. Snowfall rates at the height of the storm may reach 2 inches per hour.
Major airport hubs from Kansas City, Mo., Chicago, St. Louis, Indianapolis, Detroit, Cincinnati, Pittsburgh, Washington, D.C., Philadelphia, New York City and Boston may all be directly affected by the storm with the potential for thousands of delays and/or cancelations. Ripple-effect flight delays and cancelations are likely to reach nationwide.
One batch of snow will push slowly eastward Saturday into Sunday from the Great Lakes to part of the central Appalachians. It is during this first batch where Chicago, Detroit and Buffalo, N.Y., are likely to get most of the snow from the event.

However, it is during the last part of the storm, when the heaviest and longest-lasting snow is likely to occur centered farther south and in part of the coastal Northeast. The heaviest snow is projected to be Sunday to Sunday night over the northern Ohio Valley states to part of the central Appalachians and Sunday night and Monday in the coastal Northeast.

Initially, the storm will evolve into a blizzard over the northern Rockies and northern High Plains with dangerously low AccuWeather RealFeel® temperatures.

Farther east, the storm may be less intense in terms of wind and low RealFeel extremes, but precipitation can be quite heavy and very disruptive. The storm is likely to impact not only travel, but also school and business activities. The storm may completely tap remaining ice-melting supplies in some communities.

According to AccuWeather Chief Meteorologist Elliot Abrams, "The challenge with this storm is figuring out where the north-south boundary between rain and snow will set up and migrate to as the storm progresses slowly eastward."

A tremendous temperature contrast will set up from north to south with the storm. A distance of 100 miles could bring temperatures ranging from the 60s and 70s to the 20s and 30s and the difference between rain, ice and snow.

"In a narrow swath, all or part of the storm will deliver snow that may be difficult to shovel and plow, due to its accumulation and weight," Abrams said.

Ice is a concern in between the heavy snow and soaking rain area.
"Because of the great amount of moisture available to this storm, a narrow zone of heavy ice can occur with downed trees and power outages," Abrams said.

A shift in storm track by as little as a few dozen miles and more of a press of cold air could make the difference between heavy snow, light snow, ice and rain.

In the warm air on the southern flank of the storm, drenching rain and thunderstorms will occur. Long-duration rainfall will occur near the rain/snow line, while the potential for strong to locally severe thunderstorms sweeping through is greatest over the lower Mississippi Valley.