Forecast snowfall totals through Wednesday from the National Weather Service. (WeatherBell.com)

Millions of Americans who had to navigate a bomb cyclone and a Midwestern windstorm on Thanksgiving encountered more inclement weather when returning home Sunday and braced for more Monday, as a major winter storm takes shape in the Northeast and a new storm hits the San Francisco Bay area.

Heavy snow, mixed precipitation and strong winds are expected in the Northeast while freezing rain hits parts of Pennsylvania on Sunday, making roads hazardous. The stage is set for a burdensome Monday morning commute for many from New York to Portland, Maine.

The storm has been linked to deaths in Arizona, Missouri and South Dakota.

On Sunday night, a cluster of East Coast airports were still experiencing average delays of at least an hour because of wind, snow or mixed precipitation, according to the Federal Aviation Administration. The biggest delays were reported in airports in New Jersey, where the typical slowdown for flights into Teterboro stretched to nearly four hours.

The delays were even longer across the country at San Francisco International Airport, where high winds caused stalls for some arrivals of more than four hours on average. The Bay Area is under a high wind warning through the early hours of Monday.

Several major airlines, including Delta and American Airlines, are waiving flight-change fees for passengers likely to be stranded by the storms.

Flight disruptions are likely to continue in New England on Monday into early Tuesday, especially from Philadelphia northward to Boston, where a mix of rain and snow, along with intense winds, is expected.

Outside the East Coast

West of the burgeoning East Coast storm, more than five inches of snow had fallen by Sunday afternoon in Minneapolis. Minneapolis-St. Paul International Airport is a major hub for Delta Air Lines.

Road travel in northeastern Minnesota was not advised because of a combination of light snowfall and high winds, which was creating blizzard conditions near Duluth.

While motorists on the bulk of roadways in the rest of the Midwest were traveling at or near normal speeds Sunday morning, there were several slowdowns in northern Michigan, including along Interstate 75. Heavy snow was just exiting the region after more than half a foot dropped locally.

Delays mounted along the West Coast, as the area was hit by a significant storm system known as an “atmospheric river” because of the sheer amount of water vapor it contains.

That storm caused high winds throughout the San Francisco Bay area with gusts up to 60 mph along the Monterey Peninsula and Big Sur coast, as the National Weather Service cautioned of downed power lines. Rain has fallen intermittently in San Francisco, but the heaviest showers were concentrated south near Monterey. The storm was also dumping heavy snow on the northern Sierras.

The long-duration Northeast storm begins


A look at surface air pressure and radar-derived precipitation Sunday morning. (NOAA)

As of Sunday evening, the storm that will evolve into the first big one of the 2019-2020 winter season in the Northeast was centered over Cleveland, with a secondary low pressure system taking shape along the Mid-Atlantic coast.

The storm’s expansive precipitation shield extended like an outstretched arm well to the east, with heavy rain and downpours reaching as far south as Augusta, Ga., and northward into New Hampshire. That slug of moisture — which slowed traffic on Interstate 95 along much of the Eastern Seaboard — wrapped all the way up through Washington, Baltimore, Philadelphia, Buffalo and even into Detroit, before curling northwest as snow in northern Wisconsin and Michigan.

The precipitation initially fell as sleet and freezing rain into metro Philadelphia, New York City and Hartford, Conn., on Sunday afternoon.

From Sunday into Monday, the storm will transfer its energy to a new developing low off the Mid-Atlantic coast. That secondary low will take over as the main storm system Monday, spreading heavy precipitation up the New England coast and wrapping colder air around the back side of the storm.

One effect of the storm is that air travelers who endured extremely bumpy flights out Wednesday are also having to deal with moderate to at times severe turbulence Sunday, and are likely to do so on Monday as well, as the low-pressure area transfers its energy to a coastal storm.

Interior Northeast gets the jackpot, with rain-snow line doing a tricky dance

Wintry weather settled over the Appalachians on Sunday behind the storm’s cold front, where winter storm warnings peppered the high terrain of eastern Tennessee and western North Carolina.

For parts of Pennsylvania and West Virginia, though, the story was one of freezing rain — enough to accrete as a treacherous glaze that could turn outdoor surfaces into frosty Slip 'n Slides. With up to a quarter-inch of icing expected, the National Weather Service warned of “nearly impossible” travel conditions and sporadic power outages.

By evening, most of Pennsylvania was seeing only light rain, despite some snow in the state’s center and lingering spots of freezing rain in the east. As the storm evolves, it will bring snow to the northeast, beginning later Sunday and extending through Monday and possibly into early Tuesday. There, amounts could build to as much as 9 or 10 inches as one nears the New York border.

Snowfall totals of a foot-plus are possible in eastern New York state east of Interstate 81 by the time the long-duration storm ends. Pockets of up to 18 inches may punctuate some spots in the Catskills and Hudson Valley.


A high-resolution model's look at timing and anticipated precipitation type with the upcoming storm. Notice the messy mix for much of coastal New England. (WeatherBell.com)

Travelers getting a later start on their post-Thanksgiving journey are likely to encounter more severe weather in the Mid-Atlantic and Northeast as the storm slowly congeals, particularly Monday.

Anyone traveling there Monday morning to beat the Sunday rush is likely to encounter even more problematic conditions as precipitation gets heavier and winds increase along the coast. As cold air works into the storm’s western flank, snow will creep closer to parts of metro Philadelphia and New York City, as well as Boston by Monday night.

Although forecast uncertainty is high for the major cities themselves, areas just west of the I-95 corridor could receive several inches to more than a foot of snow, particularly in metro Boston, where precipitation will be heaviest and last the longest.

All precipitation should wind down west to east Tuesday morning, clearing all but Maine by noontime Tuesday. Regions east of I-95 in Maine could see 4 to 6 inches total, but more is possible if the rain-snow line edges farther eastward.

On Sunday evening, the National Weather Service increased the snowfall forecast for the Philadelphia, New York City, Providence and Boston areas, noting that final tallies may be higher depending on the storm’s exact track and intensity. A snowfall gradient of 10 to 15 inches could be found in just a few miles from east to west across the big cities, based on forecasts issued Sunday.

In interior Massachusetts, a foot (or more) is likely in at least two areas — one just west of the Blackstone Valley from Worcester to Fitchburg, with another along the east slopes of the Berkshires. The Weather Service is calling for as much as 14 to 16 inches there. A foot of snow may even fall closer to Boston, near Route 128, making the morning commute difficult there to some extent on Monday and also into Tuesday morning

Heavy snow is also forecast to extend into central and southern Vermont and New Hampshire. The Hudson Valley of New York and portions of northeastern New Jersey could pick up at least several inches of snow before the storm exits Monday, as colder air filters into the region.

Winds at the height of the storm will also gust near 40 mph near the coast, with less forceful breezes anticipated inland.

On the plus side, the long duration of the storm means that road crews should have an easier time keeping up with it.