The FAA is going to cut 10% of flights at 40 major markets this Friday. It's to maintain safety during the government shutdown.
Add in some winter weather wrinkles and anyone who has not thought of "Plan B" will probably regret not doing so.
Good luck travelers
I have been reading about this. I did not see what markets. Forty major markets is a lot of markets. I am glad that I do not have any plans to travel in the near future.
Here is a clue to what airports are likely to be affected
https://en.wikipedia.org/wiki/List_of_the_busiest_airports_in_the_United_States