I think we have to be careful with language as any simulation has to code for each effect:
* turbulence: this can be parameterised ‘random’ forces on a plane that have a net zero integral in any direction. I.e. the plane & contents gets bashed about in various directions but there is no ‘net’ cumulative movement over an extended period
* lift/sink/winds of various sorts: there are multiple atmospheric affects that result in a substantial air mass moving consistently up, down or sideways. EACH of those need to be calculated individually and carefully. I.e. there is rising air under every Cumulus cloud, wind blowing against a suitable slope will tend to rise, a jet-stream has a massive horizontal component.
Of course these two factors will almost always be combined, but in a simulation you have to program them differently. For the bulk horizontal movement MSFS does pretty well with “wind” and “gusts” (although IMHO the acceleration of the gusts is far too short)
There are multiple reasons for turbulence to occur, and multiple reasons for air to be moving up, down, or sideways. EACH of these needs to have planned, specific code that ends up being combined in the sim. There is no one-size-fits-all algorithm that simply makes every air particle at every scale move in a sensible direction but it’s tempting to refer to some ‘macro’ model (e.g. Asobo CFD) as if that will automatically generate every force needed. Each algorithm is good for one piece of the puzzle.
E.g. we have:
turbulence: i.e. ‘random’ air movement. Close to the ground when there’s a wind, generally in the air on a thermic day, as a modest side-effect of thermals, in a jet-stream, in strong clouds, behind another plane.
lift/sink/wind: i.e. air movement in a specific direction (to be combined with ‘turbulence’). Wind is pretty obvious. Vertical air movement under cumulus clouds, vertical air movement from heated areas of ground where cumulus clouds aren’t present (ideally Cu’s and thermals would always be linked, but if not, then it’s better the thermals are linked to the Cu’s than the ground). Possible microburst sink under CuNims. ‘Wave’ lift and sink downwind of high ground in stable air. Topographic lift/sink as air passes in close proximity to slopes, extending to a couple of thousand feet above the slope. A very complicated part of vertical air movement is that affects the clouds - at best in MSFS we’ll need to simulate that the other way around.
I’m sure there are other examples of turbulence and directional air movement, but in a simulation the best approach is to be explicit about each effect being simulated i.e. how strong are they , when/where do they occur, how long do they last etc.