Decadal predictions of late-winter precipitation in western Europe

In a new analysis published in Nature Geosciences, Simpson et al. (2019) demonstrate for the first time skillful predictions of precipitation over western Europe up to one decade in advance for the month of March. The results use decadal prediction experiments with the fully-coupled CESM climate model in which the ocean module is initialized with observed conditions and then allowed to evolve freely over the next 10 years. The experiments show high skill in predicting SST fluctuations in the sub-polar region of the North Atlantic over the subsequent decade (Yeager et al., 2018). Simpson et al. (2019) combined these SST predictions with the observed empirical relationship between SSTs and precipitation to produce skillful predictions of late winter precipitation over the UK and Portugal over the subsequent decade. These predictions suggest that over the next 10 years, the UK will be slightly wetter than it was in the early 2000's but not as wet as it was in the 1980's and 1990's and vice-versa for Portugal.