BMKG Secretly Conducts Weather Modification Operation Over Lake Toba Skies, What's Going On?
Jakarta, CNBC Indonesia - The Meteorology, Climatology, and Geophysics Agency (BMKG) is optimising the implementation of Weather Modification Operations (OMC) in the Lake Toba Water Catchment Area (DTA) in North Sumatra. This is aimed at maintaining water reserve availability while anticipating the impacts of the dry season and the El Niño phenomenon in 2026.
BMKG Head Teuku Faisal Fathani explained that this optimisation has also drawn the attention of Indonesian President Prabowo Subianto regarding national water resilience. He emphasised that his agency is continuously strengthening supporting infrastructure, such as weather radars, to accurately diagnose atmospheric conditions before cloud seeding is carried out.
“The President’s instructions are very clear: BMKG must be strengthened, particularly in carrying out weather modification operations. We are currently in the process,” he stated in an official release on the agency’s website, quoted on Saturday (2/5/2026).
The increased frequency of weather modification is inseparable from the challenges of climate change, which is predicted to bring the dry season earlier and make it last longer. OMC facilities are prioritised to maintain reservoir discharge to support the energy and agriculture sectors, as well as to prevent Forest and Land Fires (Karhutla).
“OMC will certainly continue to increase in frequency to maintain reservoir discharge and prevent Forest and Land Fires (Karhutla). In the future, BMKG is ready to provide full support in carrying out water management operations as best as possible,” Faisal said.
The series of operations in the Lake Toba region is scheduled to run for 25 days, from 9 April to 3 May 2026.
BMKG Deputy for Weather Modification Tri Handoko Seto stated that the field team has conducted dozens of cloud seeding sorties to trigger rain in the catchment area.
“As of 29 April 2026, the operation has been running for 21 days with an achievement of 33 cloud seeding sorties. There are still about four days left to optimise the operation’s achievements,” Seto revealed.
The operation is the result of synergy between BMKG, Perum Jasa Tirta I (PJT I), and PT Indonesia Asahan Aluminium (Inalum).
On the other hand, President Director of Perum Jasa Tirta I Fahmi Hidayat stated that this technology is crucial in ensuring the continuity of surface water resources for industrial and domestic needs.
“We have a responsibility to maintain the quantity, quality, and continuity of surface water resources to meet various needs, from hydropower generation, irrigation, domestic, to industrial uses. OMC support is very helpful in ensuring water availability in the reservoirs and catchments we manage,” Fahmi explained.
To date, the weather modification activity has reportedly achieved 86.78% of the total target. Thus, BMKG ensures that the OMC implementation is effective in increasing the lake’s water level without causing flood or landslide disasters in the surrounding residential areas.