Whether you fly frequently or just once in awhile here is a way to monitor the ongoing flight cancellation mess and to determine if it is getting better, worse or staying the same. The site referenced below will provide the total number of flight cancellations not only for Southwest, but for every airline.
Typically Southwest will see 15-19 aircraft per day removed from service due to maintenance issues and as this site shows, their number is well above that.
This site is also quite handy because you can click on any airline and it will show you every one of their planes currently in the air.