Jakarta. The Meteorology, Climatology, and Geophysics Agency (BMKG) has issued a warning following a significant increase in rainfall across various regions since early August. It is reported that extreme weather in the form of heavy rain and strong winds is expected to occur again in the coming days.

BMKG Deputy for Meteorology, Guswanto, stated that high-intensity rainfall has occurred in several provinces.

In Bengkulu, rainfall reached 160.8 mm/day on Aug. 1, Maluku recorded 203.5 mm/day on Aug. 3; West Sumatra 176.5 mm/day on Aug. 8; and West Java 254.7 mm/day on Aug. 9. Heavy rain also struck West Kalimantan, Jakarta, Central Papua, Banten, Riau Islands, Jambi, Southwest Papua, and Southeast Sulawesi.

“This increase in rainfall is driven by a combination of atmospheric phenomena such as the Madden-Julian Oscillation (MJO), atmospheric waves, indirect effects of tropical cyclone seeds 90S and 96W, cyclonic circulation, as well as wind convergence and slowdown around Indonesia,” said Guswanto in an official statement on Tuesday.

BMKG Director of Public Meteorology, Andri Ramdhani, added that the negative Indian Ocean Dipole (IOD) index also played a role, indicating an airflow from the Indian Ocean toward Indonesia. These factors trigger the formation of thick rain clouds, which can potentially cause heavy rain accompanied by lightning/thunder and strong winds.

Moderate to heavy rain accompanied by lightning or thunder and strong winds is forecast for August 11–13, in most areas of Sumatra, Java, Kalimantan, Sulawesi, Maluku, and Papua.

Meanwhile, from August 14–16, rainfall intensity is expected to decrease, although Bengkulu, East Kalimantan, and the Papuan Highlands may still experience heavy rain.

Strong winds are likely in Aceh, Banten, West Java, Bali, Maluku, West Nusa Tenggara, East Nusa Tenggara, South Sulawesi, and South Papua, which also carry the risk of triggering high ocean waves.

BMKG also warned of the impacts of extreme weather on the agricultural sector, especially in West Java, Central Java, and South Sumatra, which could disrupt planting and harvesting periods. Farmers are advised to avoid low-lying flood-prone areas and strengthen irrigation and drainage systems. On the other hand, the relatively dry regions of West Nusa Tenggara and East Nusa Tenggara are considered suitable for crop drying.

Tourism activities in mountainous areas, waterfalls, and the southern coasts of Java and Bali should also be approached with caution. Heavy rain, dense fog, high waves, and strong winds could endanger tourists; therefore, sea activities such as snorkeling and surfing are recommended to be postponed. For land transportation users, BMKG warns of slippery roads and landslide risks in mountainous areas.