en.malanginspirasi.com – Despite an ongoing, exceptionally strong El Niño and a positive Indian Ocean Dipole (IOD), both typically associated with dry conditions, the potential for heavy to extreme rainfall across several regions of Indonesia remains high through November 12, 2026.
Indonesia’s Meteorology, Climatology, and Geophysical Agency (BMKG) has urged the public to stay alert for hydrometeorological hazards, including flash floods, landslides, and strong winds, as weather patterns vary widely across the archipelago.
During a weather update on Friday, November 6, BMKG forecaster Sentia explained that atmospheric dynamics continue to favor the development of intense rain clouds over localized areas.
This variability was clearly demonstrated between November 1 and 4, when extreme rainfall hit several provinces.
Daily rainfall reached a staggering 358 millimeters in East Java and 300 millimeters in Bali, while Aceh recorded 167 millimeters and West Kalimantan registered 101 millimeters.
Alongside the heavy downpours, strong winds reaching up to 35 knots were reported in Lampung.
Concurrently, severe dry conditions persist in other parts of the country. BMKG monitoring stations recorded 543 locations experiencing “very long” to “extremely long” dry spells (days without rain).
Satellite monitoring also revealed high-confidence hotspots signaling fire risks, including 615 in South Papua, 255 in Central Kalimantan, and 223 in East Kalimantan.
This stark contrast highlights how severe wet weather and prolonged drought can occur simultaneously across different islands, requiring disaster preparedness tailored to each region’s specific risks.
Atmospheric Waves Driving Heavy Rain
While overall ten-day (decadal) rainfall forecasts remain low to moderate nationwide, BMKG noted that key atmospheric wave activities are driving localized heavy precipitation.
The Madden-Julian Oscillation (MJO) is currently active in phases 2 and 3 over the Indian Ocean, passing through southern Kalimantan, central to southern Sulawesi, Maluku, East Java, Bali, West Nusa Tenggara (NTB), and East Nusa Tenggara (NTT).
Simultaneously, Equatorial Rossby Waves are active across northern and central Sumatra as well as North Maluku, while Kelvin Waves are moving across northern and central Sumatra, northern and central Kalimantan, North Sulawesi, and North Maluku.
“The combined activity of these atmospheric waves, along with wind convergence, slowdowns, and high ambient humidity, strongly supports the formation of convective rain clouds in affected regions,” Sentia noted.
Weather Outlook: November 6–12, 2026
For the period of November 6–8, light rain will dominate most of Indonesia, though residents in Aceh, West Java, Central Papua, Highland Papua, and Papua should prepare for heavy to very heavy rainfall, with strong winds expected in Lampung, West Java, NTT, and South Sulawesi.
From November 9–12, risk levels will escalate significantly across Sumatra. BMKG has issued a RED ALERT (AWAS) for potential very heavy to extreme rainfall in North Sumatra, alongside a WATCH (SIAGA) for heavy to very heavy rain in Aceh and West Sumatra. Strong winds also remain a primary concern for South Papua.
As Indonesia transitions into the rainy season, the public should remain vigilant against sudden weather shifts, particularly intense downpours accompanied by lightning and high winds.
