A tropical cyclone seed, designated 96S, is currently developing in the Indian Ocean and is forecast to bring significant weather impacts to several Indonesian islands. As of Friday morning, December 26, 2025, the system is expected to generate moderate to heavy rainfall and strong winds across West Nusa Tenggara and East Nusa Tenggara, with impacts extending to the southern coast of Bali.
Weather System Details
According to the Meteorology, Climatology, and Geophysics Agency (BMKG), Tropical Cyclone Seed 96S formed on Thursday, December 25, 2025, at 01:00 a.m. local time. The system currently has maximum wind speeds of 15 knots (28 km/h) and a minimum air pressure of 1003 hPa.
The BMKG predicts that the system will slow down but intensify through Saturday morning, potentially reaching wind speeds of 20 knots in its southwestern portion. The forecast indicates an eastward movement on Friday and Saturday, though strong vertical wind shear may limit its growth. A westward turn is anticipated between Saturday and Sunday.
Potential Impacts
Beyond rainfall and wind, the cyclone seed is predicted to generate moderate high waves, ranging from 1.25 to 2.50 meters, in the waters south of Central Java to East Java, the Indian Ocean south of Central Java to Yogyakarta, the southern waters of Lombok to Timor Island, and the Savu Sea. Higher waves, between 2.50 and 4.00 meters, are likely in the southern part of the Bali Strait and the Indian Ocean south of East Java to East Nusa Tenggara.
Erma Yulihastin, a researcher at the Center for Climate and Atmospheric Research of the National Innovation Research Agency (BRIN), stated that the effects of 96S are expected to begin Friday night. While the heaviest rainfall is currently predicted for Nusa Tenggara, impacts may extend to Yogyakarta and Surakarta, and are likely to spread eastward.
Yulihastin also cautioned that strong winds and high waves are expected along the southern coasts of Bali, Lombok, and NTB, urging caution for both residents and tourists.
What Could Happen Next
If the system intensifies as predicted, the areas of heavy rainfall could expand. Should the cyclone seed maintain its eastward track, areas further east in Nusa Tenggara could experience more significant impacts. A westward turn, as forecast for the weekend, could shift the focus of the most severe weather back towards Bali and Lombok. The influence of vertical wind shear remains a key factor in determining the system’s future development.
Frequently Asked Questions
When did Tropical Cyclone Seed 96S begin to form?
Tropical Cyclone Seed 96S began to form in the Indian Ocean, south of West Nusa Tenggara, on Thursday, December 25, 2025, at 01:00 a.m. local time.
What areas are expected to experience high waves?
Moderate high waves (1.25 – 2.50 meters) are predicted in the waters south of Central Java to East Java, the Indian Ocean south of Central Java to Yogyakarta, the southern waters of Lombok to Timor Island, and the Savu Sea. Higher waves (2.50 – 4.00 meters) are likely in the southern part of the Bali Strait and the Indian Ocean south of East Java to East Nusa Tenggara.
Who has warned of the potential impacts of this system?
Both the Meteorology, Climatology, and Geophysics Agency (BMKG) and Erma Yulihastin, a researcher at the Center for Climate and Atmospheric Research of the National Innovation Research Agency (BRIN), have issued warnings regarding the potential impacts of Tropical Cyclone Seed 96S.
Given the potential for significant weather impacts, what steps can individuals and communities take to prepare for the arrival of Tropical Cyclone Seed 96S?
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