Seasonal Forecasts of Winter Temperature Improved by Higher-Order Modes
of Mean Sea Level Pressure Variability in the North Atlantic Sector
Abstract
The variability of the sea level pressure in the North Atlantic sector
is the most important driver of weather and climate in Europe. The main
mode of this variability, the North Atlantic Oscillation (NAO), explains
up to 50% of the total variance. Other modes, known as the Scandinavian
index, East Atlantic and East Atlantic/West Russian pattern, complement
the variability of the sea level pressure, thereby influencing the
European climate. It has been shown previously that a seasonal
prediction system with enhanced winter NAO skill due to ensemble
subsampling entails an improved prediction of the surface climate
variables as well. Here, we show that a refined subselection procedure
that accounts both for the NAO index and for the three additional modes
of sea level pressure variability, is able to further increase the
prediction skill of wintertime mean sea level pressure, near-surface
temperature and precipitation across Europe.