Weather forecast for Monday, 1 June 2026: Tropical Cyclone Jangmi strengthens, four regions on alert for heavy rain

The Meteorology, Climatology, and Geophysics Agency (BMKG) has released its weather forecast for Monday, 1 June 2026. Early June atmospheric dynamics are affected by Tropical Cyclone Jangmi in northern Indonesia and two active cyclonic circulations forming widespread convergence zones.

Current monitoring shows Tropical Cyclone Jangmi is active in the Philippine Sea (northeast of the Philippines) with maximum wind speeds of 65 knots and minimum pressure of 975 hPa.

The system is moving northwest to north and is forecast to strengthen persistently to category 2 or 3 within 48 to 72 hours.

This cyclone induces convergence zones stretching from the eastern Philippine waters to the northern Maluku Sea and northern Papua.

Simultaneously, two cyclonic circulations are observed in the South China Sea and the northeastern Pacific near Papua New Guinea, forming a convergence zone from the North Natuna Sea to the South China Sea.

Secondary convergence zones are also forecast to form.

These instability conditions trigger massive convective rain cloud development along wind slowdown areas.

The combination of atmospheric phenomena poses significant weather risks in several regions. BMKG urges the public to prepare for potential heavy to very heavy rainfall in affected areas.

Residents in these regions are advised to remain vigilant against hydro-meteorological disasters such as flash floods, strong winds, and landslides.

The public is advised to keep updated on weather information via BMKG’s official website at www.bmkg.go.id or social media @infobmkg.

BMKG forecasts coastal flooding (rob) in Bali until 5 June due to the full moon phenomenon.

East Nusa Tenggara residents are warned to be cautious of dry strong winds increasing wildfire risks, particularly in Sabu Raijua.

National shipping should be alert for waves up to 4 metres in several Indonesian waters until 2 June.

BMKG has issued an early warning for extreme weather from 1-4 June, with heavy rain, strong winds, and alert status in Papua Highlands.

BMKG warns of significant weather impacts across multiple Indonesian regions until 4 June due to Tropical Cyclone Jangmi.