Storm <i>Lyly</i>, the first storm with observed hurricane‐force winds in Finland

Abstract On 1 November 2024, Storm Lyly set a Finnish record for 10min average wind speeds (33.5ms −1 in Rauma Kylmäpihlaja), marking Finland’s first hurricane‐force winds and causing significant damage. The storm featured a strong pressure gradient over the Gulf of Bothnia and, while the low‐pressure centre was distant from the strong winds, thpotentially a secondary low over the Bothnian Bay. The flow of cold air over relatively warm sea led to steep low‐tropospheric lapse rates. Combined with a strong low‐level jet, this allowed strong and gusty winds in the upper parts of the boundary layer to reach the surface.