Topographic Effects On Weather
The Japanese Alps are a major weather component and dictate a lot of weather patterns in Japan. The first is when Typhoons move northward and impact Japan. If they remain on the eastern side of the Alps they will bring very heavy rain to the capitol region of Tokyo along with very strong winds. In the winter the Alps create two types of climates at the same latitude. On the Western side near the city of Kanazawa Japan, the winters can be long and harsh with snowfall amounts in the feet. While, just to the east of that region in the capital city of Tokyo, snowfall may not even get over 1ft.
The storm systems that move in from the Northwest dump all of their snow on the westward side leaving the region of Tokyo dry during these storm systems. However, if a storm were to move in from the Southwest and ride along the Alps then Tokyo would get all the moisture while Kanazawa remained fairly dry. Also when there is High pressure over Northern Japan during the winter it will push cooler waters off the Pacific back into the Tokyo region creating a cold air damming situation that can create a sharp contrast in temps during that time period. While in the summer it’s possible for strong areas of sea fog to setup along the Pacific shore, however never make it over to the other side due to the Alps blocking it.