No...Promo Awards can not be changed or cancelled.

If bad weather does indeed impact your flight, and special conditions are introduced for passengers wishing to change their flights, you would become subject to these special conditions. But until rebooking terms are announced, the original terms of your ticket will remain in effect.

There has to be more than a "chance" of bad weather - they will have to first announce a travel advisory with associated rebooking/cancellation conditions.

Good luck!