Originally Posted by tom911

The comments on the flight do indicate "long tarmac - weather". AA has already cancelled 11 flights out or ORD between 0800-1000, all regionals.

If they don't want to wait for seats on the 1225 and 1525 AA departures, assuming they go out as scheduled, consider the US departures in the morning with connections at DCA or CLT. I had an AA flight cancel earlier this year for weather, DFW-BOS, and was able to reroute on US DFW-PHL-BOS, so it's worth a shot. I also see some US flights tonight with connections.

There is a UA nonstop, but if an Avios ticket is like an AA-funded award ticket, the fine print probably says "Valid AA/OW" and you may not be able to swing rerouting on a different alliance. You can certainly ask, but with an award ticket they might not honor the request. AA's conditions of carriage only require that they route you on the next AA flight with seats.