A massive blizzard has hit the US Northeast, halting thousands of flights and closing hundreds of schools.
Officials warned that the storm could dump as much as 90cm of snow on the region.
New York, New Jersey, Connecticut and Massachusetts declared states of emergencies as tens of millions of people were urged to stay at home with transport systems suspending services.
Aer Lingus has cancelled four flights between Ireland and North America today due to the storm.
The flights affected are EI 105 from Dublin to New York at 10.50am and EI 137 from Dublin to Boston at 2pm, as well as the return services - EI 104 from New York to Dublin and EI 136 from Boston to Dublin.
Yesterday one return flight between Dublin and New York was cancelled. Aer Lingus said customers affected by the cancellations had been notified.
The potentially historic storm poses the latest challenge to New York City Mayor Bill de Blasio, who has been under fire in recent weeks from police who criticised his support of public protests about white police violence against black men.
The National Weather Service issued a blizzard warning for New York City and surrounding areas between coastal New Jersey and Connecticut, forecast to worsen overnight.
The blizzard knocked out a number of entertainment events. The New York Knicks and Brooklyn Nets called off their games and Broadway performances were cancelled.
The United Nations headquarters gave itself a day off and schools across the east coast dismissed students and cancelled classes, with those in Boston staying closed until Thursday.
"Hallelujah!" said Olivia Fitzsimmons, 8, as she headed home early from her primary school in Maplewood, New Jersey.
Even Wall Street traders rushed home, although exchanges remained opened.
As much as 60cm of snow was expected to blanket many areas along the east coast, the weather service said.
Winds topping 88km/h were predicted to lash New York City and its suburbs, raising the potential for power outages caused by tree limbs falling on overhead utility lines.
Generators, snow blowers, shovels and firewood were sold out at a Home Depot in Vauxhall, New Jersey. At a Shaw's Supermarket in Somerville, Massachusetts, canned food shelves were thinned and checkout lines long. In Brooklyn, grocery store shelves were stripped of bread and bottled water.
New York Mayor Mr de Blasio said city streets would be closed indefinitely to all traffic except emergency vehicles.
Mr de Blasio, who had been vilified for keeping schools open during last winter's harshest weather, ordered the nation's largest school system, with more than 1m students, to close.
"What you're going to see in a few hours is something that hits very hard and very fast," Mr de Blasio told reporters.
Tourists and business travellers faced headaches as airlines cancelled about 2,700 flights, including nearly 700 at the three main airports serving New York City.
At Boston's Logan Airport, the last passenger flight was to leave at midnight Irish time.
New York Governor Andrew Cuomo declared a state of emergency and deployed National Guard troops to a number of counties in the southern part of the state as well as New York City.
New York authorities said they were considering a total travel ban on main roads.
"It could be a matter of life and death so caution is required," Mr Cuomo said. "Mother Nature has decided once again to visit us in an extreme way."
New York City subways, which carry 5.5m commuters daily, will be curtailed.
New Jersey Governor Chris Christie declared a state of emergency, and sent all but the most essential government workers home, telling them not to return until Wednesday at the earliest.
The governors of Massachusetts and Connecticut told residents to expect driving bans.
"We are anticipating an historic, top-five storm, based on the snowfall," Massachusetts Governor Charlie Baker said.
The Boston-area transport system will be shut and coastal areas will likely suffer flooding, he said.
Connecticut's Governor Dannel Malloy said hundreds of thousands of people could lose power.
The biggest snowfall on record in New York City came during the storm of 11-12 February 2006, dropping 68cm,according to the city's Office of Emergency Management.
