A Case Study of the Tornadic Supercell in the Province of Pampanga, Philippines (27 May 2024)

Abstract

This study provides an integrated damage assessment, visual evaluation, environmental context, and remote sensing analysis of the tornado event that struck the suburb of Candating in Arayat, Pampanga on 27 May 2024. Satellite imagery and ground-level damage photographs reveal a $\sim$2 km path, with damage reaching EF2 intensity at one point along the track, based on the Enhanced Fujita (EF) scale. Videos of the tornado and its parent storm reveal a well-defined wall cloud and low-level mesocyclone. Subsequent radar analysis supports these and other features of a tornadic supercell. Synoptic-scale ascent in the mid- and upper-troposphere was subtle, influenced by the approach of Tropical Cyclone Ewiniar. However, a modest meridional flow aloft provided sufficient deep-layer shear to support supercell development. The southwest monsoon acted as a low-level jet, promoting warm, moist advection into western Luzon. The supercell developed around midday and was characterized by large-undiluted instability, attributed to steep low-level lapse rates. Although low-level shear and the associated near-surface horizontal vorticity were weak, the latter is highly streamwise, allowing for efficient ingestion, tilting, and stretching into vertical vorticity, which aided in tornadogenesis. Both satellite and radar data suggest that storm interactions, such as a nudging mechanism and terrain effects from nearby Mt. Arayat may have contributed to the initiation and intensification of the supercell through lee-side convergence and vorticity enhancement. The complex tropical environment of the Candating, Arayat tornado exhibits several similarities to well-documented tornadic events in North America. These findings highlight the need for further research into the atmospheric conditions conducive to tornadic activity in the Philippines.