I've always wanted weather changes in games and two of the greatest examples are in Battlefield 4. Love it or hate it they did it right. 1. A huge thunderstorm rolls in and changes the waves of the ocean, lighting effects to dark and rain pours in. The audio is the cherry on top. 2. The sandstorm that comes in from the ocean through the beaches and town changes your sight lines and blows debris everywhere making it really feel different and dramatic. If they can do it then Bungie can definitely do it! Come on Bungie please!!! :)