Detecting and tracking offshore-propagating precipitating systems formed over the Maritime Continent

In the Maritime Continent region, coastally-associated rainfall is the main contributor to the total rainfall. This type of precipitation is strongly controlled by the diurnal cycle of convection over the islands. Progress has been made to understand the sea breeze that occurs during the day but little is known about the land breeze and the mechanisms that drive the offshore propagation of convection over night. The only hypotheses that we have come from studies focusing over specific regions for a particular period of time. To achieve a more systematic study of the offshore propagation of convection, we build a dataset that identifies precipitating systems interacting with the islands of the Maritime Continent and track them throughout their lifetime. The dataset uses 18 years of the Climate Prediction Center Morphing Method (CMORPH) satellite rainfall estimates at a resolution of 8 km and 30 minutes, which allows us to precisely identify the precipitating systems right after their formation and follow them with great detail. We further filter this dataset to focus solely on the precipitating systems that form over the islands and propagate offshore during the night. It enables us to characterize the size, lifetime and speed of propagation of these systems and study the dependence of these factors on the size of the island and the large-scale conditions.