NEW YORK (CNN) - A potentially historic snow storm is expected to hit New York City Monday night. Mayor Bill de Blasio is telling New Yorkers to get ready Sunday for the extreme weather. "I want everyone to understand that we are facing most likely one of the largest snow storms in the history of this city, the recorded history of this city. The early projections for this storm are that it would easily be as much as 2 foot of snow, potentially pushing on to 3 feet of snow. So this literally could be one of the top two or three largest storms of the history of this city and we need to plan accordingly. So my message to all New Yorkers, prepare for something worse than we have seen before. Prepare to be safe," de Blasio said. The National Weather Service has upgraded its blizzard watch to a blizzard warning for the area from northern New Jersey through southern Connecticut, including New York City. The warning is in effect from 1 p.m. Monday through Tuesday.