Just up on the Metropolitan Opera page:
We are experiencing very high call volume right now, but if you have tickets for one of today’s performances and are unable to attend, please call us at 212-362-6000 at any point in the next week and we will reschedule your tickets for a future date, pending availability.
Despite the weather, all performances this weekend are scheduled to take place as planned. If you are unable to attend due to weather conditions, please get in touch with us at your earliest convenience by calling 212-362-6000.
Please be aware that we are experiencing increased call volume at the moment; if you cannot get through, please try again at a later date. Thanks and stay safe this weekend.
UPDATE: An hour later, the Met announced the cancellation of Saturday afternoon and evening performances.