By Evgenia Filimianova Contributing Writer More than 10,000 flights scheduled for between Sunday and Tuesday were canceled across the United States as a powerful nor’easter pounded the East Coast with heavy snow, strong winds and coastal flooding, disrupting air travel and prompting emergency declarations in several states. Data from FlightAware showed 3,440 cancellations on Sunday, followed by 5,535 on Monday and another 1,619 scheduled for Tuesday. On Monday alone, 88% of outgoing flights and 87% of incoming flights at John F. Kennedy International Airport in New York were canceled, according to FlightAware. At Boston Logan International Airport,…