2008: High correlation between winter precipitation and air temperature

ABSTRACT. Long-term data of winter air temperature and precipitation were analyzed and the correlation between them investigated in order to identify the factors influencing snow reduction during the recent warmer winters in the heavy-snowfall areas in Japan. A high negative correlation between winter precipitation and air temperature was identified in the heavy-snowfall areas on the Sea of Japan side in the center of the main island (Honshu). It was confirmed that precipitation is mainly caused by cold winter monsoons, and thus correlates to a large extent with air temperature in these areas. The precipitation decrease can be considered an effective factor for the recent reduction in snow as well as the snowfall to precipitation ratio. This should be taken into account for a better prediction of snow reduction in relation to global warming