BMKG warns of four-metre waves in the waters off Aceh and NTT

BADAN Meteorologi, Klimatologi, dan Geofisika (BMKG) issued an early warning regarding the potential for high waves that threaten several Indonesian sea areas. The Indian Ocean to the west of Aceh and the southern part of Nusa Tenggara Timur (NTT) have been identified as the most at-risk areas, with wave heights reaching up to four metres.

BMKG’s Director of Maritime Meteorology, Eko Prasetyo, explained that the phenomenon is forecast to occur during the period of 19-22 May 2026. The rise in wave height is considered highly risky for maritime operations, from fishing boats to large vessels.

According to the BMKG weather forecast, this condition is triggered by wind patterns in the southern region of Indonesia that are moving rapidly from the southeast. Wind speeds are reported to reach up to 30 knots, with the highest points recorded in the southern Indian Ocean off southern NTT.

“This will trigger high waves at risk levels of 2.5 to 4.0 metres to the south of NTT and west of Aceh,” said Eko Prasetyo in Jakarta on Tuesday (19 May 2026).

Eko emphasised that the wave heights are at dangerous levels. The risk is not only to traditional fishermen’s boats, but also to larger fleets such as barges and inter-island passenger ferries.

BMKG released risk analysis guidelines for safety by vessel type to minimise sea accidents during this high-wave period. Given the potential hazards, BMKG asks maritime authorities, port authorities (syahbandar), and ship operators in Aceh and NTT to tighten supervision. It is strongly advised to suspend sailing activities if weather conditions on the ground continue to deteriorate.

Residents living and working along the coast who may be affected by high waves are advised to stay alert and monitor official weather information from BMKG.