Nearly 2,000 flights have been canceled on Sunday, the day after New Year’s, amid staffing shortages and poor weather conditions in some parts of the United States. Some 1,964 flights have been canceled within, into, or out of the United States as of Sunday morning, according to tracking website FlightAware. Meanwhile, about 1,200 delays have been reported, the website’s data shows. Chicago’s O’Hare International Airport has seen the most delays and cancelations, with nearly 500 flights canceled, the tracker shows. Next is Denver International Airport with more than 200 cancelations. Sunday’s mess of flight cancelations can be blamed, in part, on snowstorms that have impacted O’Hare and Denver’s airport. Meanwhile, some have suggested that flight crew shortages are also to blame amid a bevy of COVID-19-related sick calls in recent days, which has likely been exacerbated by airlines’ vaccine requirements for staff. SkyWest Airlines, which operates flights for American, Delta, …