Rainy and Windy May: Jakarta, West Java

Jakartans should get ready with umbrellas and raincoats, with May slated to see heavy rain and strong wind in the afternoons, according to the Meteorological and Geophysics Agency (BMG). The head of BMG’s weather forecasting division, Achmad Zakir, said May will be the transition period between the rainy and dry seasons for most of Jakarta.

“The dry season will occur differently in Jakarta and its upstream areas. Jakarta’s northern areas are expected to experience the dry period in the middle of May,” Achmad told The Jakarta Post.

“The dry season in Jakarta’s southern areas such as Central, South, West and East Jakarta; Bogor; Depok and parts of Bekasi will come at the end of May or in June.”

He said the transition between the seasons usually comes in September and April.

However, he said there was nothing anomalous about this year’s weather.

Greater Jakarta has experienced rain and strong winds in the last two weeks, which have uprooted trees and damaged buildings.
Achmad said the rain was caused by reflected heat off the ground which caused the formation of cumulus nimbus clouds.

“The cumulus nimbus then trigger the local rain. It’s a normal phenomena determining the transition period from rainy season to dry period,” he said.

The BMG last week issued its official report predicting the dry season across the country.

The report, made by a team including experts from the Agriculture Ministry and the Bandung Institute of Technology (ITB), said the dry season may be shorter by between 10 and 20 days in areas such as North Sumatra, Central Java and Yogyakarta.

“But in general, the dry season is arriving as normal,” the report said.

The BMG currently operates 12 automatic weather monitoring stations to measure rainfall, temperature and wind direction in Greater Jakarta.

The agency also has meteorology stations in Tanjung Priok, Halim Perdana Kusuma, Cengkareng, Bogor, Cileduk and Central Jakarta to monitor daily climate conditions.

The team also reported that human-induced global warming had led to higher monthly rainfall in Jakarta and several other provinces.

The BMG reported that Jakarta, Banten and West Java provinces experienced a 12 percent rise in monthly rainfall from 310 millimeters in 1900 to 360 millimeters in 2000.

Adianto P. Simamora