NEW YORK CITY, New York: A powerful winter system swept toward the U.S. Northeast at the start of the post-holiday weekend, triggering emergency declarations, grounding flights, and raising the risk of hazardous travel across several states.

Forecasters warned that the storm would bring a mix of heavy snow, sleet, and freezing rain, disrupting air travel and making roads treacherous from New York to New England. The National Weather Service issued ice storm and winter storm warnings across much of New York state and Connecticut, with the heaviest snowfall up to a foot in isolated areas expected on Long Island and in the Hudson Valley.

New York City could record its highest snow totals since 2022, with snowfall rates peaking at two inches or more per hour, according to an emergency declaration issued by Kathy Hochul. The declaration warned of dangerous driving conditions as snow mixed with sleet and freezing rain in many areas.

"The safety of New Yorkers is my top priority, and I continue to urge extreme caution throughout the duration of this storm," Hochul said in a statement, advising residents to "avoid unnecessary travel."

Ice storm warnings and winter weather advisories stretched across most of Pennsylvania, much of Massachusetts, and large parts of New Jersey, where officials also declared a state of emergency. High winds were forecast to compound the impacts of snow and ice.

Snow began falling in western New York and around the New York City metropolitan area on the evening of December 26 and was expected to intensify, forecasters said.

The storm quickly disrupted air travel. More than 1,600 commercial flights within the United States and those arriving from or departing to international destinations were canceled. In comparison, over 7,800 flights were delayed as conditions deteriorated, according to flight-tracking service FlightAware.

Airports serving the New York City area bore the brunt of the disruption. John F. Kennedy International Airport, Newark Liberty International Airport, and LaGuardia Airport accounted for the majority of the cancellations, with all three issuing alerts on social media platform X, warning travelers of potential delays and cancellations.

Flight disruptions continued into December 27, with another 650 U.S. departures or arrivals called off, FlightAware reported.

Major airlines moved to ease the burden on passengers. Representatives for American Airlines, United Airlines, and JetBlue Airways told Reuters they had waived standard change fees, allowing travelers to rebook without penalty if their plans were affected by weather-related disruptions.

On the ground, New Jersey and Pennsylvania imposed commercial vehicle restrictions on some roads, including sections of major interstate highways, to reduce the risk of accidents.

"This storm will cause dangerous road conditions and impact holiday travel," said Tahesha Way. "We are urging travelers to avoid travel during the storm and allow crews to tend to roads."

Officials across the region said emergency crews were on standby as the storm continued to move through the Northeast.