Characteristics of Extreme Snowfall–Wind-Gust Events in Finland (1960–2024): Frequency, Duration, and Intensity

Abstract. Compound weather events involving both strong wind gusts and intense snowfall can have significant impacts on critical infrastructure and public safety. This study analyses the frequency, duration, and intensity of such events in Finland using ERA5 reanalysis data for 1960–2024. Extreme wind gust and snowfall conditions were identified using spatially varying 95^th and 98^th percentile thresholds. Events with both snowfall and wind gust exceeding these thresholds simultaneously were classified as compound events (SWG). SWGs were most frequent along Finland’s south facing coastal regions and eastern Finland. Increasing the threshold from 95^th to 98^th reduced the number of SWGs but emphasized the dominance of coastal areas and highlighted more severe cases. Approximately half of the events were short-lived (20 m s^˗1, hourly snowfall rates >2.5 mm h^˗1, and total snowfall >20 mm. Although rare, these high-impact SWGs can create substantial operational challenges for energy production and other critical infrastructures. The results underscore the importance of incorporating compound-event analysis into hazard assessments and preparedness strategies for regions exposed to severe winter weather.