Rain and snow began moving into parts of the East Coast on Sunday as a large winter storm advanced toward densely populated areas from Maryland to Massachusetts, prompting widespread blizzard warnings, emergency declarations, and major travel disruptions. The National Weather Service said the system is expected to intensify through the day and overnight, bringing heavy snowfall, strong winds, and potential coastal flooding.

Meteorologists warned that many communities could receive between 1 and 2 feet of snow, with snowfall rates reaching as high as two inches per hour at times. Wind gusts of up to 55 mph could create whiteout conditions and dangerous travel, while the weight of wet, heavy snow may down tree limbs and power lines, leading to scattered outages.

Blizzard warnings were issued for New York City, Long Island, Boston, and coastal areas of New Jersey, Connecticut, Delaware, Maryland, Rhode Island, and Massachusetts. Emergency declarations were announced in New York and New Jersey as state and local officials mobilized plows, emergency crews, and warming centers ahead of the storm’s peak.

New York City Mayor Zohran Mamdani announced a travel ban beginning Sunday night through midday Monday, restricting non-essential vehicles from city roads. Public schools were closed on Monday, marking the city’s first traditional snow day in several years. Officials also deployed outreach teams to assist homeless residents and expanded shelter capacity.

Air travel was heavily affected, with more than 3,500 flights canceled nationwide by Sunday afternoon, according to flight-tracking data. Airlines adjusted schedules as airports across the Northeast prepared for worsening conditions.

Local leaders in vulnerable coastal areas, including Atlantic City, New Jersey, urged residents and visitors to remain indoors, citing concerns about flooding in low-lying neighborhoods where snow could conceal standing water.

Forecasters described the system as one of the most significant winter storms to impact the region in years, with snowfall expected to taper off by Monday afternoon as cleanup efforts begin.