The Influence of Sudden Stratospheric Warmings on Extreme European Electricity Demand

Sudden stratospheric warmings (SSWs) provide a source of surface predictability up to several weeks in advance. They generally precede cold weather across the northern midlatitudes, including extremes. When it is cold, demand for heating typically increases electricity demand. We use reanalysis data and a weather‐driven demand model for various European countries to investigate the relationship between SSWs and extreme electricity demand. We find that extreme demand of ~120% of climatology is 1.5–3 times more likely in periods following SSWs across northern and central Europe. We then use subseasonal forecast experiments from the Stratospheric Nudging and Predictable Surface Impacts project to explicitly attribute the impact of the February 2018 SSW, an event that preceded a cold weather outbreak across Europe. These experiments include nudging of the stratospheric state to either its observed or climatological evolution, allowing the causal impact of the SSW to be identified. We find a robust simulated increase in extreme demand risk attributed to the 2018 event. This indicates a window of opportunity for earlier prediction of extreme European electricity demand risks following SSWs.