Implementation of Tracking Algorithm for Mesoscale Convective Systems in Flood Disaster Events Over East Belitung, Indonesia

Flooding is a significant problem with a high probability of affecting both people and infrastructure. Predicting floods is difficult because of its association with a quickly evolving convective system. Furthermore, simulating the dynamics of mesoscale convective systems (MCSs) is essential for enhancing our comprehension of the heavy precipitation systems that induce flooding. A flood in east Belitung on July 15, 2017, was suspected to have been caused by convective activity. The flood was preceded by persistent heavy rainfall from July 14 – 16, 2017, with the peak rainfall accumulation reaching >180 mm hr-1 on July 15, 18:00 UTC. This research aims to identify the type of storm system formed over the study area associated with heavy rainfall, simulate the propagation of MCSs, and increase the utilization of the algorithm detecting storms in Indonesia. We implemented the Tracking Algorithm for Mesoscale Convective Systems (TAMS) algorithm. TAMS allows for identifying, tracking, classifying, and variable-assigning to MCSs. TAMS integrates area-overlapping and projected-cloud-edge tracking approaches to enhance the likelihood of capturing the progression of the systems through time. We assigned the precipitation data from Global Satellite Mapping of Precipitation (GSMaP) to calculate corresponding statistics within the cloud area. We reveal that two cases of Convective Cloud Clusters (CCCs) were responsible for the persistent heavy rainfall. The 1st case occurred on July 14, 12:00 (initial) – July 15, 13:00 (dissipating) UTC, with an average eccentricity (ε) = 0.85 and initially formed around west Kalimantan propagated until southwest Sumatra. The 2nd case occurred on July 15, 14:00 – July 16, 08:00 UTC, average ε = 0.74, and initially formed at west Kalimantan and propagated until southwest Belitung. The pair of CCCs was triggered by a meso-low pressure and moist-warm air, which may have helped extend the lifetime of the CCCs. The elevated sea surface temperature (SST) around Belitung and northwest Kalimantan induces convective activity and forms clouds.