Brief communication: Extreme rainfall–driven flooding associated with the equatorial development of Tropical Cyclone Senyar in Aceh, Indonesia

Abstract. In late November 2025, extreme rainfall associated with the rare equatorial regeneration of Tropical Cyclone (TCs) Senyar triggered severe flooding across northern Sumatra, with Aceh Province experiencing the most severe impacts. Using satellite-based rainfall estimates from GPM IMERG, ERA5 reanalysis, and surface observations from BMKG, this brief communication provides a rapid hydrometeorological assessment of the event. Daily rainfall locally exceeded 400 mm on 25–26 November, concentrated over northern and eastern Aceh. Synoptic analysis indicates that, despite limited surface pressure deepening near the equator, persistent low-level moisture convergence and strong integrated vapor transport from the Malacca Strait, enhanced by orographic lifting along the Barisan Mountains, produced extreme rainfall and widespread flooding.