Climatology of waterspouts in the Balearic Islands (1989-2020)

Abstract

[eng] The article analyses the waterspouts recorded in the Balearic Islands (Spain) between 1989 and 2020. The extensive database used includes 234 waterspout events, which we analysed to establish their annual, monthly, seasonal and weekly spatial, temporal and hourly distribution. The autumn months account for 65% of all the waterspout events, with the highest frequency seen in September. They occur most frequently between 8:00 and 10:00 in the morning. We carried out a synoptic classifcation of the days on which waterspouts were recorded, observing that a synoptic trough pattern at 500 hPa over the Iberian Peninsula, which generates a south-westerly fow over the area under study, was the most conducive waterspout-creating condition (present in 25.3% of the events). Their relationship with the sea surface temperature was also analysed, revealing a higher frequency of waterspouts with higher temperature values, particularly between 23 and 26 °C. Finally, we examined the frequency of waterspouts in relation to the daily Western Mediterranean Oscillation regional teleconnection pattern index values, fnding that waterspouts were more common on days when the indices were closer to 0.