A High Wind Associated with Bow Echo Mesovortex over Cimenyan, Indonesia

Abstract

The high wind was noticed as the second natural disaster that frequently occurred during the last decade in the Indonesia Maritime Continent (IMC). However, the plausible mechanism of high wind still needed to be discovered due to the lack of observation measurements to detect the extreme event over a short time in a limited area over IMC. Herein, we investigated a high wind categorized as Beaufort 8 (56 km h-1) with a devastating impact on 28 March 2021 in the meso-γ-scale over Cimenyan, Bandung, West Java, Indonesia. As the first documentation of a storm-induced high wind in IMC, we combined methods of observational and numerical using X-band radar and a high-resolution (0.2 km) of Weather Research and Forecasting (WRF) in studying the physical and dynamic processes related to that extreme event. Our finding pointed out that the high wind generated by an isolated system of a short-lived (40-minute) bow echo meso-γ-vortex is a precondition of mesoscale convective complex development on a synoptic scale. The bowing stage was initiated by a meso-convergence and genesis of meso-γ-vortex as mesoscale convergence vortices under the end-line theory developed by a sustained wind, vertical vorticity anomaly, strong vertical wind shear, and rotational updraft from low-to-surface levels of the troposphere. This study suggested that the WRF model with appropriate microphysics scheme and topography succeeded in simulating a real event of a short-lived bow-echo meso-γ-vortex with 10 minutes of early initial discrepancies between simulated and observed predicts better a storm-induced high wind for hydro-meteorological mitigation over IMC.