Weather Forecast 18 May 2026: North Sulawesi on Alert for Extreme Rain

The Meteorology, Climatology, and Geophysics Agency (BMKG) has released the weather forecast for Monday, 18 May 2026. Current atmospheric dynamics indicate the formation of several local cyclonic circulation points, triggering the accumulation of moist air masses, which will result in a surge in rainfall intensity across central and eastern Indonesia.

Atmospheric Dynamics Analysis: Three Active Cyclonic Circulations

Based on weather monitoring analysis, cyclonic circulation is predicted to form at three strategic points: the Indian Ocean west of North Sumatra, the western Flores Sea, and the North Pacific Ocean north of North Maluku.

The presence of these circulation systems directly creates areas of wind confluence and wind convergence in the surrounding regions. Another secondary convergence path has been observed extending from the Malacca Strait through Riau, Jambi, West Sumatra, Lampung, the northern waters of Banten, eastern Central Java, western East Java, Central Kalimantan, northern South Sulawesi, NTT, and into the Papua region.

This unstable condition is further strengthened by widespread confluence areas stretching across the South China Sea, the Flores Sea, the southern Makassar Strait, to the North Maluku region. The combination of these atmospheric dynamics is triggering massive rain cloud growth along these wind convergence paths.

Early Warning & Preparedness

BMKG has issued Alert/Warning statuses and urges the public to increase full preparedness against the potential for:

• Very Heavy to Extreme Rain: North Sulawesi.

• Heavy to Very Heavy Rain: East Nusa Tenggara (NTT), South Sulawesi, Central Sulawesi, North Maluku, and Maluku.

Communities in these areas are requested to anticipate potential hydrometeorological disasters such as flash floods, landslides, and strong winds.