NEW YORK — A powerful nor’easter could bring blizzard conditions and more than a foot of snow to some parts of the Northeast, proving that winter is not done yet.

The National Weather Service issued a blizzard watch from late Monday night through Tuesday evening for New York City and parts of northern New Jersey and southern Connecticut, while winter storm warnings and watches were issued for the remainder of the Northeast.

Meteorologists said the storm could dump 12 to 18 inches of snow on New York City with wind gusts of 40 to 50 mph.

Mayor Bill de Blasio urged residents to avoid unnecessary travel and help keep the roads clear for sanitation crews and first responders.

“We’re preparing for a significant storm on Tuesday, and New Yorkers should also prepare for snow and dangerous road conditions,” de Blasio said.