More importantly though is that we're not too far away from the coldest region in the northern hemisphere in winter, Siberia. Cold air masses move out of Siberia and cross the relatively mild waters of the Sea of Japan. The air picks up large amounts of moisture as it moves across this body of water and then dumps some of the heaviest snowfalls on the planet along the western seaboard and mountains of Japan.
This does mean that it's pretty normal for me to get home from work and be confronted with the some difficulties getting in my front door like below.
