I think if you lighten your sky you'll find it will feel brighter without having to alter anything else directly. It will help your background mountains blend in a bit better too.
At the moment it's kind of Dark Blue/Grey almost hinting at a touch of Green (that might just be my eyesight, lol). It feels forced rather than natural, which kind of goes against the rest of the configuration because the rest of it looks and feels very natural.
A sky along the lines of this brightness level would look great for your config I think. Ignore the snow, that's just high levels of bloom and directlighting intensity.
I wouldn't say exact, you seem to want those poweful clouds so I think you'd want it a little darker (but I don't think you should over do it as you are currently doing) ,so find what's good for you. But I think it would be a good base for your setup.
Also play around with the lighting curve aswell. That can do wonders for outdoor lighting balancing (especially nights).