Subseasonal predictability of onset, duration, and intensity of European heat extremes

Abstract Successful weather forecasts on subseasonal time‐scales can support societal preparedness and mitigate the impacts of extreme events. Heatwaves in particular can, certain cases, be predicted several weeks advance. Heatwave predictability is commonly assessed terms heatwave intensity. In addition to intensity, we assess onset duration, which are crucial components early‐warning systems emergency plans. The forecast skill heatwaves investigated over European region forecasting system Centre for Medium‐Range Weather Forecasts (ECMWF). first detected ERA‐Interim reanalysis data period 1998–2017 then allocated into six clusters following regions: Black Sea (BSea), Russia (Ru), Western Europe (WEu), North (NSea), Scandinavia (Sc), Eastern (EEu). regions with highest duration Ru, Sc, NSea. WEu cluster has lowest bias intensity found most predictable number events at lead week 2. generally characteristic heatwaves, being by model ensemble mean up times 3 weeks. Furthermore, this analysis identifies allowing a further investigation physical mechanisms characteristics leading enhanced different regions.