More rain ahead in Jakarta: Experts

Abdul Khalik, The Jakarta Post, Jakarta

Jakarta and its surrounding areas as well as West Java will see more rain in the days ahead, experts say.

Researcher at the National Space and Aviation Agency (Lapan) Erna Sri Adiningsih said on Sunday that day's satellite data suggested clouds from the Indian Ocean in the South and around the Philippine area in the North were moving across to Sumatra, Kalimantan and the western part of Java.

She said a monsoon in areas between the Philippines and Sulawesi was likely to cause denser cloud coverage to the south in the next few days.

"The sun is in the northern hemisphere now. This has created lower pressure areas around the Pacific Ocean and the Philippines and higher temperatures. Extreme pressure differences caused a monsoon in the area, which in turn caused heavy cloud coverage, rain and lightning in several areas, including West Java and Jakarta," Erna said.

The rain could also be blamed on the unusually high temperature of the sea's surface in the south, which produced denser cloud coverage and in turn created rain, she said.

"We call the anomaly a negative Dipole Mode Event, caused by a monsoon and the intense rays of the sun. The Indian Ocean is warmer than usual. This will last for months, possibly as late as September or October," Erna said.

Erna said two phenomena had caused rainfall to be 15 percent heavier than normal:

The Meteorology and Geophysics Agency (BMG) previously said the dry season would start in Jakarta in April and end in November. In June and July, however, sudden copious rainfall has been regular, causing floods in the capital.

Heavy and continuous rain last Friday evening flooded the city's thoroughfares, causing traffic jams until late at night.

Last week, the BMG said this year's dry season was much like the usual wet season as cloudbursts had been common.

The BMG's head of meteorological information Achmad Zakir said rain would fall at least until the end of July as besides the cyclone in the north, the temperature of the sea's surface was similar to that of the rainy season.

He said rain would fall in southern, central, and eastern parts of Jakarta in the afternoon, while rain would fall in Bekasi and Bogor in the evening.

Achmad predicted medium to heavy rainfall with lightning in the evening and light rain in the morning.

He said the western part of Java, particularly Bandung, Merak, Serang, and Cilacap, as well as several parts of Sumatra, would continue to have rain until the end of July.