A winter-season meteotsunami in the Balearics: the 22 January 2021 squall-line driven event

Abstract On 22 January 2021, an active squall line embedded within cyclone Hortense swept across the Balearic Islands, significantly impacting Mallorca and Menorca. The event was characterized by extreme wind gusts, including a peak of 130 km h −1 at Palma Airport, breaking a 50-year record. The squall line induced an outstanding long-lived pressure jump, which triggered moderate meteotsunami activity across several harbours and coastal inlets. Recent improvements in observation systems have allowed us to gather enough data to investigate, for the first time in the Balearic region, the dynamics of a meteotsunami associated with a convective pressure jump. Taking advantage of currently available quantitative prediction systems, this study also analyzes the predictability of this type of phenomenon. The phenomenon of January 22, 2021, is quite unique, not only for the detail with which it has been described, but also because it is a winter meteotsunami, as for the western Mediterranean, meteotsunamis are typically warm-season phenomena. Furthermore, this episode was accompanied by strong winds, associated with a deep depression, which is unusual for Mediterranean meteotsunamis.