A Case Study of the Tornadic Supercell in the Province of Pampanga, Philippines (27 May 2024) (2504.20559v3)

Abstract: This study provides an integrated damage, visual, environmental, and remote sensing analysis of the tornado event that struck the suburb of Candating in Arayat, Pampanga on 27 May 2024. Satellite imagery and photographs of the damage indicate that the tornado caused EF2 damage on the Enhanced Fujita (EF) scale across a $\sim$2 km path. Videos of the tornado and its parent storm reveal a well-defined wall cloud and low-level mesocyclone, but without a sign of precipitation curtain, indicative of its low-precipitation mode. Subsequent radar analysis supports these and other tornadic supercell features. Mid- and upper-tropospheric synoptic-scale ascent was subtle, influenced by the approach of TC Ewiniar. However, a modest meridional flow aloft over the area 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 mid-noon and was characterized by large-undiluted instability, attributed to steep low-level lapse rates. Although low-level shear and its 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 (i.e., nudging process) and terrain interactions with nearby Mt. Arayat may have contributed to the initiation and intensification of the supercell through lee-side convergence and enhancing vorticity. The complex tropical environment of the Candating, Arayat tornado mirrors several characteristics of well-documented North American tornadic environments. This highlights the need for more research into the atmospheric conditions conducive to tornadic activity in the Philippines.