You have now entered into the wonderful world of speycasting! In effect spey casts (and there are several of them) are jump-roll casts with a change of direction. On running water of course you often need to change direction of the cast because the fly has swung around on the current.
Now the fun bit. If the wind is blowing downstream you must keep the fly below you and roll from your downstream arm. If the wind is blowing upstream then you must position the fly upstream of you before you make the final cast (jump roll) using the upstream arm. It is quite wonderful the ways you can achieve this. I suggest you search YouTube for spey casting but for now here is a good one. (no one casts this way on a river - but shows how much fun it can be!)
Enjoy the learning journey!