As AA and US are still largely operating as separate airlines, you've posted in the wrong forum (the Announcement at the top of the page explains where to post).
Please read, in the AA (pre-merger forum):
Weather delays, system IRROPS, policy, resources etc. (winter 2014-15)
We'll probably move this there, but in the meantime the thread contains some valuable information.
Happy travels and new year.
/Moderator