BPBD: Weather Modification Effectively Reduces High Rainfall in Jakarta

The Jakarta Regional Disaster Mitigation Agency (BPBD) together with the Meteorology, Climatology and Geophysics Agency (BMKG), Indonesian Air Force (TNI AU), and PT RAI, successfully conducted a Weather Modification Operation (OMC) to reduce high rainfall intensity in Jakarta yesterday.

OMC Jakarta successfully achieved a reduction in rainfall of 50-60 percent

Jakarta BPBD's Logistics and Equipment Subgroup Head and spokesperson for OMC 2025, Michael Sitanggang, stated the reduction in rainfall was expected to reach 50-60 percent from the predictions.

"Based on the accumulated rainfall in Greater Jakarta released by BMKG, OMC Jakarta successfully achieved a reduction in rainfall of 50-60 percent from the predictions released before the cloud seeding process was conducted," he stated, Wednesday (2/5).

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According to him, yesterday's flight was conducted in two sorties using 1,600 kg of NaCl seed material, targeting the Southwest-West and Northwest-West areas.

"The first seeding from 9:30 AM to 11:55 PM was conducted in the Southwest region of Banten - Sunda Strait waters. Meanwhile, the second seeding took place from 2:05 PM to 4:10 PM in the Southwest to Northwest regions of Jakarta."

BMKG's Weather Modification Governance Acting Director, Budi Harsoyo explained that based on the weather forecast analysis, in general, the conditions in the western part of Java, especially Greater Jakarta, are expected to have light to moderate rain from the afternoon until early morning.

"Potential for rain is influenced by MJO activity in quadrant five, which contributes to cloud formation in the western part of Java, including Greater Jakarta," he explained.

He added the determination of the seeding location today is based on the wind predictions in the Greater Jakarta area. It also considers the wind predictions in the Greater Jakarta area coming from the West-Northwest, with speeds of 5-48 knots.

"While, at the 925-500 hPa layer, winds are blowing from the Southwest-Northwest direction, with wind speeds ranging from 5 to 48 knots and humidity levels between 40-100 percent, thus it can be said that the targets today are in the West, Southwest, and Northwest regions,"  he explained.

As information, the total amount of NaCl seed material that has been used up to today is 3,200 kg, with the usage details being on February 2nd, 2025, with 1 sort of 800 kilograms of seed material, on February 3rd, 2025, with 1 sort of 800 kilograms of seed material, and on February 4th, 2025, with 2 sorts of 1,600 kilograms of seed material.