A nor’easter is a storm that travels along the US East Coast and typically has coastal winds out of the northeast.

“Nor’easters usually develop in the latitudes between Georgia and New Jersey, within 100 miles east or west of the East Coast,” the National Oceanic and Atmospheric Administration says.

They typically form between September and April and are strongest during the winter months.

Traveling north along the eastern seaboard, these storms often intensify as warm ocean water near the Gulfstream – a strong ocean current that brings warm water from the Gulf of Mexico into the Atlantic Ocean – clashes with Arctic air from the north.

These temperature differences provide “the fuel that feeds Nor’easters,” NOAA said.

Nor’easters regularly affect some of the most densely populated US cities, including Washington, DC, Philadelphia, New York and Boston, as well as Canada’s maritime provinces.

Nor’easters bring torrential rain and/or snow, gusty winds and extremely high surf that can cause coastal flooding.

These impacts can kill people, disrupt travel and damage property.

Most notable nor’easters

Blizzard of 1888: This storm killed 400 people as it pummeled the northeastern US from the Chesapeake Bay to Maine with nearly 50 inches of snow between March 11 and 14. Snowdrifts – some two stories high – shut down transit, stranding travelers and halting the delivery of coal needed for heating.

“At the time it was called the ‘worst storm in living memory,’ and it still holds the distinction of the worst winter storm on record in many areas of the Northeast,” the National Weather Service said.

Ash Wednesday storm of 1962: This March storm has been considered the strongest nor’easter of the 1900s. It struck the Mid-Atlantic states with 40-foot waves, pushing homes off their foundations and into the ocean. Some 45,000 homes were damaged in New Jersey alone, NOAA said.

The storm was stronger that most hurricanes and caused more than $200 million in damage at the time, the agency said.

1993’s “Storm of the Century”: This storm, which also hit in March, was one of the worst nor’easters ever recorded and among the deadliest and costliest weather disasters of the 20th century. The storm produced up to 90-mph winds along the coast and dumped as much as 60 inches of snow inland.

As the Arctic warms, nor’easters may get worse

As the world faces the climate crisis, extreme winter weather – specifically major snowstorms in the northeastern US – have been tied to warming Arctic temperatures, according to a study in the scientific journal Nature Communications by Atmospheric and Environmental Research, the Massachusetts Institute of Technology and Rutgers University.

Major winter storms were two to four times more likely when the Arctic was abnormally warm compared to when it was abnormally cold, according to research that looked at how severe winter weather, extreme cold and heavy snowfall in US cities related to conditions in the Arctic during and before the storms.