Yep, gusts can greatly alter the instantanious airspeed over the wings. The wind can change direction and velocity and the inertia of the model takes a while to catch up. But during that time the model ends up being affected quite a bit.

Charlie P, strong vs mild doesn't really alter the elevator needs other than if it's a variable gusty wind. If the wind is smooth it just means that you want to start the approach more overhead than way off downwind. Don't confuse airspeed with ground speed. Mind you if the model in the "approach mode" is flying so slowly that it's got a negative ground speed then it's time to alter the landing procedure and deal with the reality of having to actually make it back to the field. That's a situation where a single fixed landing mode elevator trim is just not going to work out.