Nor'easter heads for New England, New York; California braces for another atmospheric river: Live updates

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Millions of residents in California were steeling themselves Monday for yet another atmospheric river storm that will sweep through the state Tuesday and Wednesday, which in recent weeks has been slammed with unrelenting and historic storms.

Meanwhile, residents in New York and other Northeastern states readied for rough weather over the next couple of days as a nor'easter began to take shape on Monday.

“Increasingly, stormy weather is expected to impact both the West and the East Coasts simultaneously over the next couple of days with the arrival of two separate but potent low-pressure systems,” the National Weather Service said.

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Atmospheric river brings more rain, snow to California

More than half of the Golden State's territory was covered by a wind, flood, or winter storm watch, warning, or advisory on Monday as a frontal system in the Pacific Northwest shifted south toward California, the weather service said.

AccuWeather meteorologist Jon Porter said "once again, there is the potential for heavy rain resulting in major flooding, mudslides, road closures, feet of mountain snow and very strong wind gusts from Tuesday into Wednesday."

A strong low-pressure system was expected to bring heavy rain to the Bay Area and central California, along with feet of snow to the Sierra Nevada mountains, according to the weather service.

“Excessive runoff from heavy rain and snow melt may result in flooding of roadways, rivers, creeks, streams and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks,” National Weather Sacramento said in its flood watch advisory, which extends into Wednesday. "Flooding may occur in poor drainage and urban areas, especially where snowpack is blocking drains and culverts.”

FEMA resources mobilized in California

In Southern California, communities were still reeling from the effects of a brutal blizzard that struck the Los Angeles and San Bernardino mountains two weeks ago. Gov. Gavin Newsom declared a state of emergency in more than a dozen counties, including San Bernardino County, where officials have worked to reach people trapped inside snow residences.

The Federal Emergency Management Agency announced Friday it would provide assistance to the region.

Nor’easter is on the way

A winter storm warning was in effect for portions of nine northeastern states on Monday, including New York, New Jersey, Pennsylvania and the six New England states. Although most areas will see 6 to 10 inches of snow, up to 20 inches of heavy, wet snow was forecast in some parts of eastern New York and western Massachusetts, which could lead to power outages from downed tree limbs, the weather service warned.

“This could be deadly,” New York Gov. Kathy Hochul warned at a storm briefing in Albany. “Let me repeat: This will be a dangerous storm. Please stay off the roads for your own safety.”

Hochul, who will issue a state of emergency starting at 8 p.m. Monday, said snow plow crews from Long Island and utility crews as far away as Canada were being sent to the region.

In addition to the snowfall, strong winds of up to 50 mph were also predicted, along with coastal flooding. The combination of heavy snow and strong winds will produce "dangerous to impossible travel," the weather service said.

The coming storm is known as a nor'easter, which are large, intense areas of low pressure that typically develop off the East Coast during the late fall, winter and early spring.

The storms are called "nor'easters" because they usually bring strong northeast winds over the East as they move north along the Atlantic Coast.

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Freeze warnings in the South

Widespread freezes both Tuesday and Wednesday morning are expected from

the Tennessee Valley into portions of the South and Southeast, according to the weather service. "Freeze warnings are currently in effect across these regions, where recent above-average temperatures have accelerated the spring growth cycle," the weather service said.

Winter storm in the North-central U.S.

Portions of Wisconsin, Michigan and Minnesota were under winter storm warnings Monday morning as the region emerged from a weekend of substantial snowfall.

The weather service in Green Bay said Green Bay and nearby Wisconsin communities picked up an additional 3-8 inches of snowfall on Monday and warned residents of slippery road conditions. The region had already seen 3-6 inches of snow over the weekend.

Winter storm tracker

Contributing: Rene Ray De La Cruz, Victorville Daily Press; the Associated Press

This article originally appeared on USA TODAY: Live weather updates: California atmospheric river; nor'easter looms