Find here cancellation policy of American Airlines for know what happens when American Airlines cancelled flight due to bad weather...
If a flight is cancelled due to a significantdelay caused by weather or a natural disaster, American Airlines can refund thefull cost of the fare. Passengers will be given several choices in such cases:
1. A full refund
2. Any unused fare will be converted into creditthat the passenger may use for future travel. The credit must be used within ayear of the cancellation date.
3. Passengers can make free changes withoutpaying the $200 cancellation fee charged by American Airlines.
Read More- https://www.cheapflightinfo.com/travel/flight/american-airlines-cancellation-policy
