Indonesia tornado database: Tornado climatology of Indonesia

Abstract

The climatology of tornadoes, waterspouts, and funnel clouds for Indonesia is compiled into a new tornado database based on newspaper archives, online news, and social media (X, YouTube), covering the period from 1800 to 2024. We present the analysis over two periods: (i) historical and (ii) recent periods. The climatology includes the annual, monthly, diurnal, and geographical data for tornado cases. Based on a review of 47 669 reports mentioning tornadoes, we identified 436 tornado cases with sufficient evidence to be classified as tornado events. In the recent period (2010-2024), the annual frequency of tornadoes was 16.20 cases yr-1, while in the historical period (1800-2009), the annual frequency was 1.10 cases yr-1. Tornadoes were mostly documented in Java Island, followed by Sumatra and Sulawesi. The monthly variability of tornadoes shows a maximum during November, followed by December and January. The peak of the diurnal cycle of tornado cases is between 13:00 and 17:00 Local Solar Time.