I'd doubt a Judge would deem "jetstream winds" and being "held when arriving at JFK" extraordinary circumstances bearing in mind the wind blows from West to East across the Atlantic every day and there's been arrival delays into JFK ever since the Wright Brothers got airborne. This is why airlines pad-out their block times from dep to dest to cover these sort of eventualities (and more) so despite departing 1 hour late, you usually miraculously arrive on-time.
A short response to them stating the above and reminding them that they need to prove both events were exceptional should result in it going into the "no win" pile. If no joy, MCOL is your friend :-)