Gov. Phil Murphy​ declared a State of Emergency across 21 counties in New Jersey that will be in effect at 8 a.m. Sunday.

The heaviest snow was expected to fall in New Jersey between 4 and 9 p.m. Sunday, with totals of up to 8 inches.

Snowfall forecasts have increased for a winter storm expected to blanket New Jersey with widespread areas of 4 to 8 inches of snow. Winter storm warning areas were expanded early Sunday and a state of emergency is in effect. National Weather Service and AccuWeather

With a winter storm moving in, New Jersey is under a State of Emergency Sunday morning. The State of Emergency, declared by Gov. Phil Murphy, went into effect at 8 a.m. Sunday. The state is expecting heavy snow totaling up to 8 inches followed by extremely low temperatures.

The Lehigh Valley is under a winter storm warning Sunday for 4-8 inches of snow. Here’s when it will start and what to expect.

The NYC area is forecast to see significant snow on Sunday as New Jersey declares a state of emergency. Here's how much to expect, when the storm will stop and end, plus how to track live coverage:

The Lehigh Valley is now under a winter storm watch for up to 8 inches of snow Sunday, according to the National Weather Service.

"The level and extensiveness of the frigid air may be tough to match the rest of the winter," forecasters warned.

An arctic air mass settled over New York City and much of the country Sunday evening, bringing a deep freeze and the chance of more snow than the city has seen in three years.

The snow started falling in the early afternoon and will become heavier in the early evening, according to the National Weather Service.

The snow from Sunday’s winter storm is starting to pile up in some areas of New Jersey, with as much as a half foot measured on the ground in parts of Morris, Passaic and Sussex counties as of 8 p.m.