A 500 mb synoptic climatology of pacific north‐west coast winters in relation to climatic variability, 1948–1949 to 1977–1978

Abstract Within the context of a 500 mb synoptic climatology, relationships between synoptic types and Pacific north‐west coast climatological regimes are investigated. Distinct fluctuations in thermal and moisture trends are identified for the winters of 1948‐1949 to 1977‐1978. Within any one of these climatological regimes, interannual variability in temperature and precipitation is related to the frequency of occurrence of synoptic types associated with warm and wet conditions, respectively. However, the analysis suggests that mixing of data from differing regimes may contribute to within‐type variation, often identified as a major methodological problem in synoptic climatological research.