Found this on the net.

How to cast during windy weather
Fish and Fishing

To be honest, the wind is not a friend to flyfishing anglers. However, instead of locking heads with it, you better know how to adjust to it!

The stronger the wind is, the more you need to cast on the parallel plane, parallel to the water surface, because the wind will have a lesser effect if we cast into the opposite direction!The frontal wind is most sensitive, especially because it complicates the leader's enveloping in the air. In that case it is best to perform longer casts than necessary, so as to reach the desired distance. At the last moment, before the fly touches the water surface, it is important to pull the line so as to perfectly develop the leader.

The side wind can tangle the line right or left from the place in which we want to set up the fly. The only solution is to target on the side when you cast and and try to continually straighten the line's orbit, depending on the wind direction.

Back wind seems like a good ally, because it carries the line to a greater distance and makes it easier to develop the line in the air, as well as setting up the fly in the most meticulous manner possible.