ECMWF extended-range forecasts and the European heatwave of summer 2018
The heatwave of summer 2018 highlighted the skill and value of our extended-range (sub-seasonal) forecasts. Forming part of ECMWF's seamless prediction system, the extended range falls between the medium- and long-range (seasonal) timescales. Forecasts on the extended-range timescale are scientifically challenging, but skill has been increasing steadily.