This story was last updated at 4:40 p.m. ET on Monday.

0n Sunday, Winter Storm Blair disrupted more than 10,300 flights as snow and freezing rain swept across the Central Plains and Midwest. As the storm now moves out of the East South Central and into the Mid-Atlantic region, Monday is bringing more delays and cancellations.

The U.S. air travel system is definitely feeling the storm’s impact. As of 4:40 p.m. ET on Monday, 6,340 flights have been delayed and 1,967 canceled, according to FlightAware, a free app that provides flight tracking data. Based on historical trends, travelers can expect that thousands more flights will be disrupted as the day progresses.

The three major Washington, D.C.-area airports—Reagan National (DCA), Baltimore (BWI) and Washington Dulles (IAD)—are all reporting triple-digit flight cancellations. And in the Midwest, St. Louis Lambert (STL) and Chicago O’Hare (ORD), have also notched more than 100 cancellations each.

ForbesWinter Storm Blair: 10,300+ Disrupted Flights On SundayBy Suzanne Rowan Kelleher

Major U.S. airlines are issuing travel waivers allowing passengers flying in or out of impacted airports to rebook without paying the fare difference, but the number of airports covered varies widely by airline. For example, American Airlines’ travel advisory covers 46 airports while Delta Air Line’s advisory covers 20 airports.

For consumers looking to change travel plans or recoup travel expenses, much will depend upon the airline, itinerary and, in some cases, whether a travel insurance policy was purchased.

If you are flying through an airport covered by your airline’s travel advisory, take the waiver. The earlier you accept it, the more options you’ll have for rebooking flights for another day.

ForbesWinter Storm Blair: Airlines Issue Travel Advisories Through MondayBy Suzanne Rowan Kelleher

How to Predict and Manage a Flight Delay or Cancellation

Even if you’re not flying through an East Coast airport, your flight may still see disruptions. Statistically, your flight is more likely to get delayed the later in the day you fly because disruptions tend have a cascading effect. That’s because of the way airlines reuse planes for multiple flights in the same day. When a plane has a delay or cancellation on one flight, it will subsequently arrive late for the next one, and the next one, and so on.

FlightAware has a helpful tool that can tell you if your plane is behind schedule, which can give you an early heads-up that a problem may be brewing. Enter your flight information, and then click the “Where is my plane now?” link just under the flight number. You’ll be able to see if the plane is ahead of schedule, on time or behind schedule and can take action accordingly.

Download your airline’s app and check your flight status before you go the airport. Last-minute notifications are uncommon, so you may save yourself the trip to the airport. If you get a notification that your flight is delayed or canceled after arriving at the airport, expect long lines at the service counter. Be aware that often you can help yourself more quickly with the airline’s app. Also, be on the lookout for self-serve kiosks with your airline’s brand.

Still, some situations require a human’s help. It will be first come, first served at the counter, so heed early warning signs that your flight will be delayed, and don’t stray far from the departure gate. When it’s your turn, stay calm and be polite. You can be sure the ticket agent is having a rough day, too.