LAUSR

Two different mesoscale convective system (MCS) events that produced the heavy rainfall over the Greater Jakarta (GJ) during 15–18 January 2013 period were investigated. The purpose of the present study is to analyze the atmospheric conditions of two different MCSs during the heavy rainfall. Data consist of 3 hourly rainfalls of meteorological stations, infrared satellite, sounding, 6-hourly surface wind and reanalysis data. The first MCS was developed at 16:00 LT on 14 January 2013 over the eastern coast of Sumatra covered an area of 249,732 km2 at maximum size, with about 16 h durations. The next MCS was developed at 22:00 LT on 16 January 2013 over the northern coast of the GJ in 9 h of duration, and maximum covered area around 55,829 km2. A warmer and moist air was observed on the low-level layer in the evening of 16 January 2013 (prior of second MCS), in comparison to 14 January 2013 event. Combination of both the surface strong wind perturbation and equivalent potential temperature in the second MCS might be contributed to heavy rainfall over the GJ than the first one.