The structure of tropical Sumatra squalls

Abstract

Sumatra squalls are commonly occurring, vigorous and deep convective systems that emanate over Sumatra, sweeping eastwards across the strategically important Malacca Strait shipping route and affecting the population of 85 million people who live in the region. Despite their disruptive potential, there is a paucity of literature on the structure and dynamics of Sumatra squalls. In this article, the structure of the 12 July 2016 Sumatra squall was studied using a high‐resolution Weather Research and Forecasting Model simulation (version 3.7.1). After comparing the reflectivity patterns of both the simulated and actual Sumatra squalls, we showed the large‐scale features of the Sumatra squall: the rear‐inflow jet, ascending front‐to‐rear flow, wind shear and cold pool generation. Following that, we took advantage of the high resolution of the simulation to examine the detailed features of this Sumatra squall and the signs that the conventional squall line propagation mechanism is responsible for Sumatra squall propagation.