A Synoptic Climatology Of Alaska: Winter 700Mb Height Anomaly Patterns And Surface Climate Variability, 1956-1986

Abstract

An objective, descriptive study of Alaska's winter season synoptic climatology is compiled to identify regional monthly 700mb anomaly height patterns and to investigate monthly-mean surface temperature and precipitation variability during the thirty-year period from 1956/57 to 1985/86. A total of 78% of the period's monthly 700mb anomaly height maps are classified into ten Basic Anomaly Pattern categories by a Kirchhofer/Lund-based pattern classification scheme. Patterns are described in terms of frequency of occurrence, climate associations, and specific climate events (case study format). Examination of the winter monthly-mean temperature and precipitation records for the nine NOAA-designated Alaska climate divisions, and the Gulf of Alaska indicates a cool, dry period in the January record from 1964-1977. The winters following 1977 are the most variable of the thirty-year record. Seasonal-scale linear trends indicate a warmer, drier shift in the interior divisions and a warmer, wetter shift in the southern coastal divisions. <p>