BMKG Predicts Extreme Weather in East Java, OMC Deployed to Secure Eid Exodus

Juanda Class I Meteorological Station predicts that East Java has the potential to experience heavy rain accompanied by thunder and strong winds from 11 to 20 March 2026. In its statement, the Meteorological, Climatological, and Geophysical Agency (BMKG) explained that this extreme weather is influenced by atmospheric dynamics such as the Madden-Julian Oscillation (MJO), Kelvin waves, and unstable atmospheric conditions that support the growth of convective clouds. BMKG stated that the potential for extreme weather risks causing hydrometeorological disasters such as floods, landslides, and disruptions to public activities, including during the 2026 Eid exodus period. BMKG emphasised the need for active mitigation steps to reduce the impacts caused. In response to these conditions, BMKG and the East Java Regional Disaster Mitigation Agency (BPBD) have launched a Weather Modification Operation (OMC) to secure the Eid exodus flow from extreme weather threats. This operation, centred at the Juanda Lanudal Post, runs from 16 to 25 March 2026, focusing on controlling rainfall intensity in disaster-prone areas. BMKG Supervisor Alif Kurniawan explained that up to yesterday, the joint team had conducted 7 flight sorties with a total duration of 14 hours and 1 minute over the first three days of implementation from 16 to 18 March. The operation used 6,800 kg of seeding materials consisting of 1,000 kg of NaCl and 5,800 kg of CaO, seeded into potential clouds in the skies over East Java. “This active step has proven effective in reducing average rainfall by up to 40 percent compared to normal conditions without intervention,” said Alif, as quoted from the BMKG statement on Friday (20/3/2026). Preliminary evaluations also show significant results, where incidents of heavy rain have decreased by around 70 percent, while very heavy rain has reduced by about 25 percent. Rainfall distribution is now more controlled and has shifted to the light category, thereby reducing the risk of disruptions on exodus routes.