From cx.com:
Adverse weather conditions in the US and Canada
Latest update: 14 Mar 2017 2:00 HKT (GMT+8)
Due to winter storm Stella in Northeastern US and Canada, flights to and from these areas can be affected. We advise our customers to delay any trips to these areas for the next few days.
The following flights have been cancelled:
CX830/14MAR From Hong Kong to JFK, New York
CX831/14MAR From JFK, New York to Hong Kong
CX840/14MAR From Hong Kong to JFK, New York
CX841/14MAR From JFK, New York to Hong Kong
CX888/13MAR From Vancouver to JFK, New York
CX889/14MAR From JFK, New York to Vancouver
CX845/15MAR From JFK, New York to Hong Kong
CX846/14MAR From Hong Kong to JFK, New York
Flights delayed:
CX812/14MAR From Hong Kong to Boston
CX811/15MAR From Boston to Hong Kong