NTB Still Rainy as El Niño Strengthens

REPUBLIKA.CO.ID, Mataram — The Meteorology, Climatology and Geophysics Agency (BMKG) predicts that most parts of West Nusa Tenggara Province (NTB) will still be subject to rain. This is expected to occur even as the El Niño phenomenon strengthens toward moderate by the end of May 2026.

‘From 21-31 May, there is a 50 to 80 percent chance of rain with an intensity of more than 50 millimetres per ten-day period, occurring across almost all of NTB,’ said forecaster Nindya Kirana of the BMKG NTB Meteorology Station in Mataram, NTB, on Thursday (21 May 2026).

Moreover, Nindya said, there is a 10 to 40 percent chance of rainfall exceeding 100 millimetres per ten-day period expected in parts of the province. These include West Lombok, Central Lombok, North Lombok, East Lombok, West Sumbawa, and Bima.

BMKG notes that the Indian Ocean Dipole (IOD) is currently in the neutral category with an index of -0.099. The neutral IOD is forecast to move into a positive condition from July 2026.

As for the ENSO or El Niño Southern Oscillation, it is currently in the weak category with a sea surface temperature anomaly in Nino 3.4 of +0.97 degrees Celsius.

This condition, Nindya explains, is expected to develop into a moderate El Niño during May-June-July 2026.

He said that the air mass flow across much of Indonesia is currently dominated by easterly winds. The winds bend and converge around the equator.

Sea surface temperature anomalies around most of Indonesian waters are normal to warm. The Madden–Julian Oscillation (MJO) is currently active in phase 2 (Indian Ocean), but is predicted to gradually become inactive.