For most Americans the thought of visiting Disneyland during a snow storm is, well, pure fantasy. California and Florida are both known for their mild winter weather, so unless Mother Nature is sleeping on the job you'll never see a genuine snowflake in a United States Magic Kingdom.
Unlike Los Angeles and Orlando, snowfall in Tokyo is a normal winter occurrence. When I first saw photos of Tokyo Disneyland after a snow storm I was taken aback. Tokyo Disneyland looks enchanting on a sunny summer day, but snow gives it a whole new personality—it truly deserves to be called a Winter Wonderland.
When I actually got to visit Tokyo Disney Resort on a snowy day however, the experience was slightly less captivating than I had imagined it would be. The temperature in Tokyo on the coldest of days doesn't get much below freezing, which means the snow tends to be on the slushy side and makes trudging around the park kind of a sloppy affair. The cast members do their best to keep the expansive walkways free of the semi-melted snow, but unless you're wearing galoshes, chances are your socks are going to get wet. Bad-weather days usually mean small crowds and consequently leads to short lines to ride the rides, but unfortunately attractions that are even partially outdoors (like Splash Mountain and Big Thunder Mountain) close down when it snows. Naturally parades and shows on outdoor stages are canceled.
One thing I wasn't expecting were the Snow Mickeys. Since many of the cast members have some extra time on their hands due to the reduced crowds, many of them make snowmen in the shapes of Disney characters. Mickey Mouse is the most prominent, but you'll also see Donald Duck and even Stitch. They come in a variety of shapes and sizes and some of them can be quite elaborate. They add a whole other level of charm to the snowy-day experience.
If you're planning on visiting Tokyo Disneyland during the winter and you have a choice between going on a day when snow is forecast or going on a nice-weather day, I would pick the nice-weather day. Although the snow adds a good deal of picturesque majesty to the landscape, sloshing around in the cold, wet snow gets old quickly and you'll miss out on several major attractions that will be closed. On the other hand, if you've been to Tokyo Disneyland already and get a chance to visit on a snowy day, I would recommend it if you can deal with the cold. It's definitely a unique experience you'll never get at any of the Disney parks in the USA.