How does La Niña / El Niño affect each resort differently? ONI-based seasonal snowfall predictions for Japan's top ski destinations.
The Siberian Express: Cold, dry air from Siberia crosses the Sea of Japan — one of the warmest seas at that latitude. In just 500-800km, the air mass absorbs enormous amounts of moisture from the warm Tsushima Current below.
Orographic lift: This moisture-laden air hits Japan's mountain spine and is forced upward. Rapid cooling at altitude produces extremely low-density snow — often just 3-5% water content, compared to 8-12% in the Alps or Rockies.
The result: "Japow" — arguably the lightest, driest powder snow on Earth. Niseko averages 14-18m of cumulative snowfall per season. Myoko Suginohara regularly exceeds 12m. No other developed ski region on the planet matches this consistency.
La Niña amplifies this: During La Niña winters, the Siberian High strengthens and shifts south, producing colder temperatures over the Sea of Japan. Warmer water + colder air = even more moisture pickup = even more snowfall. This is why ONI is the single strongest predictor of Japanese seasonal snowfall.