Thos screenies look very promisiing, but how do the clouds look in BOS? Did they finally manage to replace the cotton balls for some more realistic looking clouds? That would really be the icing on the cake for me.
Current weather doesn't have clouds yet.
If you want to have a baseline, the original version of the game engine is used in Rise of Flight which does have clouds, so we know the game engine can perform at least to that level. Depending on how the developers choose to implement clouds, I'd expect them to be at least that quality, and probably slightly improved.
Just so you know, though - making realistic, good looking clouds is quite difficult. To reproduce "real" clouds' appearance, you would have to essentially make a pretty complicated weather system which would then determine whether water vapour in a certain "cell" of air is completely vapourized or partially condensed into water droplets, and how large those water droplets are. Essentially you'd have to track temperature, density, and humidity throughout your game atmosphere, then implement movements of air as wind, convection currents, etc. etc. based on relative parametres of the air. To get really fancy you could also add the possibility of ice crystals forming, which are needed to produce high altitude clouds like Cirrus, Cirrocumulus, and the top parts of Cumulonimbus clouds.
If you do it with small enough cell size, in theory you should be able to reproduce any cloud formation in existence - completely procedurally. You would get natural "cauliflower" appearance of Cumulus clouds, and you could get the even grey overcast Stratus or Nimbostratus clouds, simply depending on how your simulated weather system is behaving.
However - and this is a big however! - the processing requirements for this kind of system are
staggering. To create even a simplified weather system requires a very, very large number of "cells" to interact with each other, and then calculating the simulation in real-time requires basically supercomputers. At this time, we cannot implement this type of system on consumer level electronics, which is probably why it hasn't been done in games.
Mostly, clouds are done with particle systems of some kind, either with lots of small particles "filling" a volume of a cloud's shape (volumetric particles), or with coarser, larger particles with a billboard type texture, dropped into the game in a fixed pattern to create an appearance of cloud from all directions. IL-2 uses the latter type of clouds, and I think most other games use a similar system because large numbers of particles have been too much for most gaming systems in recent history. However, advances in graphics card technologies have made it more feasible to use volumetric particles to create things like smoke, fog, or indeed clouds.
It remains to be seen which one gets used in Battle of Stalingrad but I'm not too worried - it'll probably be perfectly acceptable, good looking solution.
And now, some screenshots to make this post more acceptable for this thread:
"Another successful landing, comrade!"