Thousands of flights within, into, or out of the United States were canceled or delayed on Jan. 16 as winter storm Izzy battered the southeastern United States with heavy sleet and snow, knocking out power to tens of thousands of households. A total of 3,059 flights within, into or out of the United States were canceled Sunday, while 5,056 flights were delayed, according to FlightAware data. American Airlines led the pack, with more than 670 flight cancellations, including over 90 percent of the flights into and out of Charlotte Douglas International Airport in North Carolina, an American Airlines hub. PSA Airlines saw 522 cancellations, Southwest 343, Delta 248, and United 94, according to FlightAware, whose so-called Misery Map showed ongoing delays and cancellations into Monday, mostly at airports in the east of the country. Izzy’s snow and ice pounded parts of the Midwest on Friday and Saturday, before spreading south on …