A wall of winter weather rolling across a wide swath of the northern United States on Tuesday ushered in sleet, snow, ice and commuter headaches to more than 100 million people from Seattle to New York.

The storms were part of an even larger system of weather misery that brought tornado warnings to Mississippi and concerns over torrential rains, high winds and flooding to parts of Georgia, Alabama and Florida, AccuWeather meteorologist Tyler Roys said.

“This storm is unique in that it brought a significant storm to Seattle and a wintry mess to so many big cities – Chicago, Detroit, New York and Boston,” Roys told USA TODAY. “When you include the South, the storm is impacting almost every part of the United States in some shape or form.”

Almost 100,000 homes and businesses were without power in Washington state alone, another 100,000 plus in the Midwest. More than 4,000 flights were canceled or delayed nationwide, including 1,000 in and out of New York’s Kennedy and LaGuardia airports.

Newark International Airport reported some incoming flights were being delayed at departure cities by four hours.

Commuters across most of the nation’s northern tier were also affected. Green Bay, Wisconsin, could see 10 inches before the snow stops. Parts of Michigan were paralyzed by freezing rain.

“Expect your drive to be at least twice as long,” Michigan’s Transportation Department warned Detroit commuters. “Icy rain making for tough driving conditions. SLOW DOWN!”

Parts of northern New Jersey were bracing for up to eight inches of snow and ice, and Gov. Phil Murphy declared a state of emergency for the entire state. Upstate New York and northern New England could see up to 18 inches.

In New York City, Mayor Bill de Blasio warned that morning snow was forecast to morph into a wintry mix.

“We’re expecting winter weather to continue through the afternoon,” de Blasio said. “Please stay off the roads — use mass transit if possible. We’re monitoring the situation closely.”

Areas north of Baltimore were hit with more than five inches of snow Monday topped by sleet and freezing rain Tuesday. In Philadelphia, a passenger was injured when a SEPTA bus jackknifed and crashed into a North Philadelphia home on a snowy, slick street.

Schools in Seattle and across much of the area were shuttered for a second straight day Tuesday. The city, which averages less than 7 inches of snow a year, already has seen three times that amount. Boston’s snow total since Jan. 1: 2.2 inches. Seattle: 20.2 inches.

A mix of rain and snow continued to fall Tuesday. This has been Seattle’s snowiest February on record, the National Weather Service reported. 

“Here’s another statistic that sets this month apart,” the Seattle weather service office tweeted. “Including ALL months going back to 1894, there have been only been 5 months (including this one) in which 6+ inch snowfall occurred twice in the same month.”

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Even Hawai’i has been under siege, although the storms eased Tuesday. The state Parks Division reported that “for perhaps the first time ever” snow has fallen in a Hawai‘i State Park. Sixty-foot waves and wind gusts up to 191 mph also were part of a fierce weekend storm that toppled trees and power lines.

“The forecasters were calling this an unprecedented event and we concur,” said Sam Lemmo, administrator for the state Office of Conservation and Coastal Lands. “We rarely if ever have seen the combination of record high on-shore waves, coupled with gale force winds.”