Variability and trends of total precipitation and snowfall over the United States and Canada

Abstract

Century-long time series of unbiased annual precipitation over the regions to the south of 55°N and 40-year time series of unbiased area-averaged annual precipitation and snowfall for all of North America are developed. The analysis of their trends shows the following. 1) During the last 100 years, annual precipitation has increased in southern Canada (south of 55°N) by 13% and in the contiguous US by 4%; however, the main domain of this century-scale precipitation increase is eastern Canada and adjacent to it northern regions of the US. 2) Up to a 20% increase has occurred in annual snowfall and rainfall during the last four decades in Canada north of 55°N. -from Authors