Yes this is it! OP, just watch this 2 minute video. He explains why Southwest (who is having most of the issues right now) is cancelling so many flights.

Southwest is having an issue due to their point to point system for flights. Basically there are two ways airlines can set up their flight schedules:

Spoke and Hub - They have a big airport as a hub, and to get to or from a smaller airport you connect through the hub. This is what most airlines uses.

Point to point -This is what Southwest is using. Basically, they have a series of planes and crews doing loops all across the US. So one crew might be based out of St. Louis, and in a day they might be scheduled to fly from St. Louis to Omaha, Omaha to Oklahoma City, then Oklahoma City back to St. Louis.

The issues is best described using an example.

So let’s say I want to go to Fargo, North Dakota from Oklahoma City.

On Delta with the spoke and hub method, I would likely first fly to one of their hubs in Atlanta, then I would get on a flight with people from all over to go to Fargo from there. So if my flight from OKC to Atlanta gets cancelled, I am SOL, but that only affects maybe one other flight (usually a return flight from Atlanta to OKC).

Under Southwest’s model, I might have the same route (OKC to ATL to Fargo), but my OKC to Atlanta flight being cancelled causes issues elsewhere, because that crew and flight isn’t available for their next flight. Jeff, who was supposed to be the pilot for my plane from OKC to Atlanta, he’s stuck in Oklahoma City. So now Southwest doesn’t have a pilot for his flights from Atlanta to Charlotte or from Charlotte to OKC either.

So even though OKC is the only city with bad weather, Southwest has to cancel his flights from Atlanta to Charlotte and Charlotte back to OKC later that day.

Somebody please link that Fox video explaining it below. It’s really good at ELI5 this actually.