Extreme Rainfall in Katulampa Associated with the Atmospheric Circulation

Extreme rainfall will increase the river flow and it can be triggered by regional and global atmospheric circulation. Objective of this study is to analyze the intensity of rainfall in Katulampa and its associated with the atmospheric circulation. We found that the extreme rainfall threshold in Katulampa is 67 mm in December-January-February (DJF) which is determined using 95% percentile method. The number of extreme rainfall events is 86 days during 1981 to 2013. The results showed that increasing of rainfall intensity in Katulampa is influenced by the Madden-Julian Oscillation (MJO) and cold surge. MJO and cold surge modify the transport of water vapor and triggering the formation of convective clouds over the Java Island. Phase 2,3,4 and 5 of MJO have the highest impact on increasing rainfall intensity in Katulampa which is characterized by Outgoing Longwave Radiation (190 - 210 W/m2). Meanwhile, the cold surge event has time lag about 1-2 days to increase the rainfall intensity in Katulampa.