Weather regime forecasts are a prominent use case of sub-seasonal prediction in the midlatitudes. A systematic evaluation and understanding year-round forecast performance is still missing, however. Here we evaluate representation skill for seven Atlantic–European weather regimes reforecasts from European Centre Medium-Range Forecasts. Forecast calibration improves frequency biases most strongl...

A new automatic forecasting procedure is proposed based on a recent exponential smoothing framework which incorporates a Box-Cox transformation and ARMA residual corrections. The procedure is complete with well-defined methods for initialization, estimation, likelihood evaluation, and analytical derivation of point and interval predictions under a Gaussian error assumption. The algorithm is exa...

GloSea5, a seasonal forecast system of the UK Met Office, shows reasonable skill among state-of-the-art operational systems. However, average surface temperature (T2m) in winter (December–February) GloSea5 is particularly low East Asia. To improve over Asia, we focused on high score global teleconnection patterns simulated by GloSea5. Among well-predicted patterns, selected those highly correla...

Abstract Despite the growing demand for seasonal climate forecasts, there is limited understanding of landscape organisations providing this critically important information. This study attempts to fill gap by presenting results from an in-depth dialogue with entrusted provision forecasts World Meteorological Organisation, known as Global Producing Centres Long-Range Forecasts (GPCs-LRF). The p...