TEMPO.CO, Jakarta - The Meteorology, Climatology, and Geophysics Agency (BMKG) has issued an early warning of potentially high waves in several areas of Indonesian waters on November 17-20, 2025.
According to BMKG forecaster Marina Ayu, wind patterns in northern Indonesia generally move from northwest to northeast, with speeds ranging from 6 to 25 knots. In southern Indonesia, winds typically move from southeast to southwest, with speeds ranging from 6 to 25 knots.
"The highest wind speeds were observed in the western Indian Ocean from Nias to the Mentawai Islands, the Karimata Strait, and the northern Pacific Ocean off Papua," Marina said in a written statement on Monday, November 17, 2025.
She said that these conditions have caused waves to reach heights of 1.25 to 2.5 meters in the northern part of the Malacca Strait and in the southern Indian Ocean off the coasts of Banten, West Java, Central Java, Yogyakarta, East Java, Bali, West Nusa Tenggara, and East Nusa Tenggara. They have also caused waves to reach these heights in the northern and southern parts of the Karimata Strait.
Similar waves are likely to occur in the western, central, and eastern parts of the Java Sea; the southern, central, and northern parts of the Makassar Strait; the Maluku Sea; and the northern Pacific Ocean off the coasts of Maluku, Southwest Papua, West Papua, and Papua; the western, central, and eastern parts of the Arafura Sea.
Meanwhile, very high waves of 2.5 to 4.0 meters are likely to occur in the western Indian Ocean off the coasts of Aceh, Nias Islands, Mentawai Islands, Bengkulu, Lampung, and the northern Natuna Sea. "Potential high waves in several areas could pose risks to maritime safety," she said.
Marina urged the public to be cautious, especially fishermen using fishing boats. They should avoid wind speeds exceeding 15 knots and wave heights above 1.25 meters. Barges should be wary of wind speeds exceeding 16 knots and wave heights above 1.5 meters.
For ferry boats, they are advised to avoid wind speeds exceeding 21 knots and wave heights above 2.5 meters, while larger vessels such as cargo ships and cruise ships are asked to be cautious of wind speeds exceeding 27 knots and wave heights above 4.0 meters.
"We urge people living and working near areas prone to high waves always to remain vigilant," Marina said.