I also love the falling snow look, and I'm impressed with AF tracking a flying bird in snow. But, I don't like the lighting for two reasons.
First, the overcast day brings a need for higher iso, thus noise, thus loss of detail.
Second, the overcast/snowy conditions bring completely flat lighting, where I'd prefer to see some directionality to the lighting, helping to define the shape of the bird.
It's an awesome shot (we really do have 3 winners), but it's missing a tiny bit from being first.