The making of Church in snowstorm, step by step...

First I removed the backround.

Do a render clouds and change to screen mode.

I did a layer of light blue over the church and also a layer of white.

Then to bring out background effect, use the style blending. hold move tool on a segment and while holding down Alt drag and split the adjuster to the left until the background starts to show through.

Another cloud layer, change to screen mode and add some snow flakes on a new layer.