The snow‐shadow effect of <scp>Sado Island</scp> on <scp>Niigata City</scp> and the coastal plain

Japan's Hokuriku region, near the Sea of Japan, typically experiences heavy snowfall; however, Niigata City, largest city on Japan side, lower levels snowfall than neighbouring cities. This study investigates snow-shadow effect Sado Island in located 45 km away leeward. Statistical analysis long-term radar data for 10 winters showed that effects plain occurred 151 (80%) 188 cases, during which a strong approaching wind reached island. The location this was always downwind and depended direction. Numerical experiments using Weather Research Forecasting model predicted over Plain would be lighter with island without it. Additionally, occurs areas more 150 downwind. reduces heat fluxes from sea surface by weakening leeward winds. At same time, horizontal convergence is weakened. Meanwhile, orographic amount water vapour, cloud ice sea. Therefore, prevents lines redeveloping can further reduce plain, including City.