Per the WSJ, you should invert the TSA's 311 rule if you have flight delays on your trip. Namely, they recommend a 131 approach.
The one is the app Flighty which will let you know when trouble is brewing. Frankly I think you can substitute several other apps here since there are many that provide flight info.
The three is to immediately contact your airline for rebooking/rerouting by tweet/app, by phone and in person. At the same time.
The final one is for the DOT's website Airline Customer Service Dashboard.