NEW YORK, 29 Jan. (AFP) -- Thousands of flights in the United States were cancelled on Saturday (Jan 29) as parts of the East Coast braced for a shellacking by a powerful winter storm packing heavy snow and high winds.

Places in the North East, including New York and Boston, were expected to bear the brunt of the far-reaching system, which is also predicted to pummel the Mid-Atlantic.

Salt machines and snowplows were at the ready in New York, where Mayor Eric Adams tweeted that 30cm of snow was predicted, but warned that "Mother Nature has a tendency to do what she wants".

Some 3,400 flights were already cancelled for Saturday traveling within, into or out of the US, according to flight tracker FlightAware.

Cancellations on Friday totalled more than 1,450.

The National Weather Service warned of "whiteout conditions and nearly impossible travel at times," along portions of the Mid-Atlantic and New England coasts, with snowfall accumulations greater than a foot expected in parts of the same region.

The governors of New York and New Jersey declared a state of emergency while Boston mayor Michelle Wu declared a snow emergency.