Interesting and moody landscapes. While I like the textures in the clouds, I wonder a bit about the reality of the very dark gradient at the top of both images (more so with the first one). It gives the images a bit of a top-heavy look and affects the overall balance of the images.
I find your logos a bit intrusive as well (they should not end up being a compositional element).
I agree with Manfred. Subtlety is watchword with something like this. If you want the sky to be that dark, then the rest of the image has got to reflect that mood AND you need to look at the transition from dark to light.
Briefly looked at these and they do convey the impression of a snow storm very well. Then read the comments, agreed the grad on the top is just a little severe particularly on the first image (my favourite) and you should lose that watermark.
I really liked the first one more; it shows how the dark clouds are invading the mountain and valley.......all the three images are beautiful....
The last one is less interesting than your first ones.
The foreground is much to dark and could use some heavy-duty dodging to bring out the details, The mountains themselves work very well, bu the cloud cover overpowers the image. Some dodging to lift them up would be worth considering.
I like the first one, very moody.
Nice efforts on the first two, kudos on the image in post#4, very dynamic composition however might suggestion raising the shadows in the foreground and upper sky area.
the third was posted because it's straight out of camera and shows exactly what the clouds were like that day. it's unedited except for being resized. i didn't even bother to fix the tilted horizon, just hit the reset button in lightroom and exported it.
this is the edited version, the exact same processing was applied to this as the first two images.