2026/04/30 by Generich H. Capuli
Physics and Astronomy · #physics.ao-ph
36 pages, 16 figures, 3 tables. Submitted to ESEV (Springer Nature). While I welcome discussion and feedback, I am currently not considering collaborations or changes to authorship for this study. Thank you for your understanding. The supplementary damage analysis can obtained by downloading the source files of this preprint (.zip)
arxiv created 2026/08/05 · arxiv updated 2026/08/06
(Abridge) On 13 September 2025 around 22 UTC, a localized tornado outbreak affected eastern Philippines, causing significant damage in Camarines Norte. The event developed within an atypical easterly severe weather regime characterized by warm, moist southeasterly flow and strong low-level wind shear associated with an easterly wave trough. A vorticity convergence zone along the inverted trough enhanced low-level rotation, while highly curved streamwise hodographs indicated a favorable environment for supercells and tornadogenesis. At least five vortices were identified, including three tornadic supercells. The Magang tornado was rated IF2.5 (EF3-equivalent) with ∼2 km damage path, while the Cahabaan and Napilihan tornadoes were rated IF1 (EF1-equivalent), with Cahabaan producing ∼3 km damage path. The remaining vortices were rated IF0 (EF0-equivalent). These tornadoes occurred simultaneously, indicating multiple discrete supercells within the same mesoscale environment and possible inflow-outflow interactions. Dual-polarization radar observations revealed ZDR and KDP columns, a debris signature in the Magang tornado, and a bounded weak echo region (BWER) in the Cahabaan supercell. This study documents the first known tornado outbreak and simultaneous tornadic supercells in the Philippines within an easterly severe weather regime.