Turbulence in most flight sims is just a artificial rocking of a plane and not an effect of the moving air currents. My suggestions is that in FS 2 it is done right. For example:
On a sunny day, a late spring day with a steep temperature gradient (unstable air) there wil be turbulence as an effect of rising and sinking air (thermals).
Near mountains the turbulence is an effect of the mechanical turbulence created by wind and obstacles. Wave turbulence would be really great.
Wind sheer turbulence would also be nice.
Off course this would mean that the weather settings would need imputs for at least:
- wind strenght at different heights
- temperature of the different air layers (dew points, etc.)
- wind directions at different heights
This way you could create inversions, determine the strenght and height of thermals and thus turbulence (so no sliders for thermals, but indirect by setting temprature at the surface and in the air (condor has a good working system)), determine the amount of wind sheer, determine the wind gradient, etc. If it is done right you could create weather that has chances for thunderstorm development, tubulence at different strenghts at different places, challeging landings due to wind sheer and wind gradient, mechanical turbulence behind buildings and tree lines, etc.
Real weather data would effect the same variables and would simulate the conditions of the real world at that point in time, not just picture them.
I probably forgot a great deal, but maybe it is of some use in the development.