Due to the 737 Max 8 aircraft being grounded, Southwest is canceling about 3.25% of their flights, due to an aircraft shortage. Canceled flights not only are those scheduled to be flown with a Max aircraft; some aircraft are being reassigned to flights that were to be flown with the Max. Customers are very upset. They are being told, in some instances, that their flight was canceled due to a "maintenance issue."
Some recent cancellations have been the day before date of travel. Southwest now says that they will cancel with a five day notice. Unfortunately, coming into peak travel season, there will be very few open seats, booking five days in advance.
With no end in sight, Southwest began ferrying the 737 Max 8 aircraft to the Mojave Desert on Saturday, to wait it out.
For those with upcoming Southwest flights, don't assume your flight will operate, since it was not scheduled with a 737 Max 8. This is a very unfortunate situation, which is not Southwest's fault.