Southwest Airlines is suffering a holiday hangover that’s causing a headache for thousands of travelers from Baltimore to San Diego. According to FlightAware, over 2,900 flights into, within or from the United States have been canceled today. Of those flights, Southwest is responsible for some 2,500 cancellations. And Baltimore-Washington International Thurgood Marshall Airport has the fourth highest number of canceled flights. Only Las Vegas, Denver and Chicago have more. Here are five things you need to know if you’re stuck at BWI or another airport with hopes of getting home before 2023.