In recent years, the skill of state-of-the-art seasonal forecasting systems has significantly improved, and some exciting evidence of skill in winter extratropical predictions has emerged. However, forecast skill is notably lower in Europe, especially in summer. A better understanding of the physical mechanisms driving European weather and climate variability is critical for making improvements in monthly to decadal forecast skill and longer-term climate predictions. This session seeks contributions that focus on physical mechanisms of European natural climate variability and weather, for example by identifying remote driving factors, by analyzing precursor signatures or performing targeted model experiments. We welcome contributions studying drivers including (but not limited to) the tropics (e.g. ENSO, MJO), the extratropics (e.g. North Atlantic ocean, sea ice loss, Eurasian snow cover, PDO, AMO) and the stratosphere (SSWs, QBO). Impacts of external forcings, such as solar and volcanic activity, on Europe and also paleoclimate studies are welcome in the session. Submissions using any of the following approaches are encouraged: analysis of observed/reanalysis data, operational forecasting systems or models of varying complexity within the hierarchy of models.