Did this a few days ago ---
No weather exception (ORD) (doing a MR) until I get to the airport & my flight to IAD is boarding. Informed by g/a's that most flights out of ORD are already delayed up to 3 hours.
Beat it from the gate to the UC and ask to be rerouted through IAH on my return instead of ORD. Told to head to my plane, muy pronto, and things would be handled. Get to IAD and bingo I'm F/C via IAH and back home.
"Who ya gonna call?" My wife telling her that I'll be home earlier than expected!^^^