| Recently, cold snowy regions of Japan have occasionally seen trends of lighter snowfall due to warm winters, heavy snow in areas that previously had little snowfall, very heavy localized snowfall, and other unusual snowfall patterns. It is considered important for the snow and ice control to understand the climate change-related metamorphosis of snow and ice environments to enable contribution to the development of long-term snow and ice-control plans and measures. Accordingly, in this study, trends of change in snowfall and snow cover over the last 26 years were surveyed using past data. The items surveyed were seasonal maximum snow depth; accumulated seasonal snowfall; maximum 24-, 48-, and 72-h snowfall from the onset of snowfall; the frequency of days with snowfall totaling 30 cm or more; and the number of days with continuous snow cover in winter. The collected results revealed that the annual maximum depth of snow cover and the number of days with snowfall totaling 30 cm or more were on the rise in eastern Hokkaido, where it faces the Sea of Okhotsk and the Pacific Ocean. In general, this region is considered to have little snowfall as long as stable winter pressure patterns continue, while snowfall increases when low pressure develops over the Pacific Ocean and the Sea of Okhotsk. It was clarified that there were changes in snowfall patterns and in the distribution of areas with heavy snowfall. |
