Most of the nation’s flight cancellations or delays were concentrated in the Northeast early Tuesday

A winter storm warning covered parts of the Northeast, including Connecticut, New York, Massachusetts, New Jersey and Rhode Island

Snowstorms flank US, with Northeast, California digging out

The Madrid region was among the worst hit areas with levels of snowfall not seen since 1971.

Madrid blanketed in snow as deadly storms cause chaos across Spain

More than 650 roads were blocked by snow, leaving some drivers stuck in their cars from Friday night until Saturday