Why does the Sea of Japan coast receive heavy winter snow?

The heavy winter snowfall along the coast of the Sea of Japan is primarily caused by the interaction between cold continental air and the sea's relatively warm waters.12

From December to March, the prevailing northwest monsoon carries cold, dry polar air masses from the Asian mainland across the warmer waters of the sea. As this air travels over the water, it picks up significant moisture, fueled in part by the Tsushima Current.123

When these moisture-laden winds reach the mountainous terrain of Japan, the air is forced to rise. This orographic lifting causes the air to cool, resulting in heavy precipitation in the form of snow along the western, mountainous coasts. In contrast, by the time these winds cross the mountains to the Pacific side of the country, they have lost most of their moisture, leading to dry and windy conditions there.123