NEW YORK — A massive winter storm pummeled all five boroughs on Saturday, dumping nearly a foot of snow, keeping most New Yorkers at home, complicating travel and lingering throughout the day. The windy, frigid dump was both an unexpected and, for some, unwelcome surprise. “It’s pretty big,” said Andrew Chan, 43, who was with his children at Madison Square Park around midday. “This one seems unexpected.” Daughter Kara 7, however, was fine with it, offering a 1-to-10 rating of “100.” “We had thought the brunt of this would come in the late night hours and have moved on by now, but the storm lin…