Walking

First of all, we have here a good composition. You placed the subject in a appropriate place. The frame is well chosen too, the clouds and the snow give drama to the scene. Our eyes are guided by the person.

However, I can notice some things that doesn't suit the picture.

The biggest concern is the dust all over the picture. This is really annoying and should be reduced to the strict minimum. In fact, this is the second thing that caught my eyes in this picture! You can easily wipe them out with Photoshop or Lightroom.

I personally would not have taken 50/50 sky/ground. Here, it gives less drama and we are directly guided to the skyline and the person is a bit hidden/masked by this.

I would also have smoothen the picture in order to get the noise reduced, but this is not really a problem as the noise is not really apparent/disturbing here.

The last thing I could discuss is about the snow : you could have made it more white, but this is just "personnal taste".

As a conclusion, I'd say the biggest issue is the dust. The rest is fairly good, may be a different angle of view (ie not 50/50 ground/sky) would have been better.

Keep going!