BMKG Issues Warning as Heavy Rain Looms Across Several Regions of Indonesia

BMKG reports the formation of several cyclonic circulations and convergence zones that could increase rainfall across various parts of Indonesia on Friday, 22 May 2026. The atmospheric dynamics associated with these features could trigger heavy to very heavy rainfall in several regions.

BMKG forecaster Alya Sausan said the cyclonic circulations are currently observed off the western coast of Bengkulu in the Indian Ocean, the Makassar Strait, the Maluku Sea, and the northern Pacific Ocean off Papua.

‘This condition significantly increases the potential for rainfall cloud development around the cyclonic areas as well as along the convergence and confluence zones,’ Alya said on Friday.

BMKG notes that the convergence and confluence zones stretch from the western Indian Ocean near Aceh to the western part of West Sumatra, the Flores Sea, the Maluku waters, and from the Halmahera Sea to the Philippine Sea.

Furthermore, convergence zones were detected in Riau, Central Kalimantan, the southern part of the Makassar Strait, the Banda Sea, and the Seram Sea. Meanwhile, confluence zones form in the Andaman Sea, the Philippine Sea, the Arafura Sea, and the northern Pacific Ocean off Papua.

Based on the atmospheric dynamics analysis, BMKG urges residents in the Bangka Belitung Islands, West Kalimantan, and Maluku to heighten their vigilance for the potential of heavy to very heavy rainfall.

For western Indonesian cities, thunderstorms are forecast in Pangkal Pinang, Palembang, Pontianak, and Banjarmasin. Serang is expected to experience light rain.

Jakarta, Bandung, Semarang, Yogyakarta, Surabaya, Pekanbaru, Tanjung Pinang, Bandar Lampung, Tanjung Selor, Samarinda, and Palangka Raya are forecast to receive light rain.

BMKG also predicts Banda Aceh, Medan, Padang, and Bengkulu will be dominated by cloudy to overcast skies, while Jambi may experience hazy conditions.

In eastern Indonesia, thunderstorm rain is forecast for Manado, Kendari, and Sorong, while moderate rain is possible in Nabire.

Additionally, Gorontalo, Palu, Mamuju, Makassar, Ternate, Ambon, Manokwari, Jayapura, Jayawijaya, and Mataram are predicted to experience light rain. Denpasar, Kupang, and Merauke are forecast to remain cloudy to heavily overcast throughout the day.