Antecedent rainfall, wind direction and seasonal effects may amplify the risk of wind-driven power outages in the UK

Abstract Windstorms are the main cause of large power outages in the United Kingdom, primarily through windthrow (the uprooting or breakage of trees by winds that then fall on overhead lines). Future risk assessments of power outages focus on wind speed alone, ignoring potential contributions of windthrow such as antecedent rainfall, wind direction, and seasonal factors (leaf cover). Here, using power outage data in the United Kingdom for 2006–2018, we demonstrate that ignoring these additional contributions to windthrow can result in a 2- to 5-fold underestimation in the probability of large power outages during windstorms. Furthermore, incorporating these variables within a statistical model alongside wind speed significantly improves the predictive skill of power outages during windstorms compared to a model that only includes wind speed. Results highlight the need to include multivariate effects in climate risk assessments to guide resilience planning and manage the changing risks due to climate change.