Initial Impression:
A plethora of blue, neat idea. Missing something.
Challenge:
This meets the challenge perfectly in my opinion.
Composition:
There's not much to say here, I think you've done well for your subject matter. Maybe cropping out the top third would have made it a bit more digestable to the eye, but I think that's personal preference.
Technical:
The blue is definitely there and it serves to invoke a melencholy mood. I would like to see a little more contrast to darken the tree branches up, but not too much.
Overall:
Good weather shot, definitely suits the challenge and stirs emotion in me. Good job.
Definite weather. This shot through the window makes me feel like a kid not able to go play ball. I would like to see the color tone just a bit in the warmer side.