What is thundersnow, the rare phenomenon that could hit New York City?

Thundersnow, an unusual winter weather phenomenon, could hit the US northeast on Monday night, forecasters said.

New York City could see thundersnow — when lightning forms within a snowstorm — through Tuesday morning, National Weather Service meteorologist Bryan Ramsey told The Independent.

“Right now, [thundersnow] is something we’re considering,” Mr Ramsey said, adding that forecasters will know more about its likelihood by Monday evening.

Thundersnow is rare because it requires both warm and cold air to collide in just the right way to spark lightning, according to Mr Ramsey.

If warm air collides with a snowstorm, it can create turbulent winds within the system. In turn, these winds cause ice crystals to collide, causing high enough charges to spark lightning, Mr Ramsey explained.

While thundersnow is possible, nothing will be certain until hours before the wintry conditions begin to hit New York and the surrounding region.New York City could see up to eight inches of snow, while the rest of the state, along with parts of Connecticut and New Jersey, could see up to a foot.

Ahead of the storm, New York City Public Schools announced that Tuesday will be a virtual learning day.

This week’s Nor’easter comes roughly a month after the first winter storm of 2024 hit the region. That freezing blast ended a two-year snowless streak for several cities including New York and Philadelphia.

Storm Indigo in January knocked out power for hundreds of thousands of homes, caused travel chaos, and killed several people across the US.