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The World Meteorological Organization's El Nino/La Nina Update puts the chance of El Nino persisting to February 2027 at nearly 100 percent.
It is the first time a WMO update has expressed this level of certainty about an ENSO event.
The Nino 3.4 index rose from +1.5 degrees Celsius over May-July 2026 to +2.0 in July, and to +2.2 to +2.6 in weekly values from late July to mid-August.
Sub-surface waters in parts of the tropical Pacific ran more than 8 degrees Celsius above average in July and early August.
A positive Indian Ocean Dipole, forecast at about +0.9 degrees Celsius for September-November, may partly offset the drying effect over India.
El Nino is the warm phase of the El Nino-Southern Oscillation, a coupled ocean-atmosphere cycle in the tropical Pacific. Trade winds weaken, warm water shifts eastward, and the displaced rainfall belts alter weather worldwide.
Simple Analogy: A pan of water tilted the other way: the warm layer sloshes east, and the rain follows it.
Specialised agency of the United Nations for weather, climate and water; issues the periodic El Nino/La Nina Update drawing on its Global Producing Centres of Long-Range Forecasts
The difference in sea surface temperature between the western and eastern tropical Indian Ocean. Its positive phase tends to support Indian monsoon rainfall and so works against El Nino's drying influence.
1997-98 and 2015-16 are the benchmark strong El Ninos of the modern record, with the Nino 3.4 anomaly in 2015-16 peaking near +2.6 degrees Celsius.
WMO and national meteorological services have asked members to use the long lead time to activate early warning and preparedness systems.
GS Paper I > Geography > Important geophysical phenomena; GS Paper III > Environment and Disaster Management
General Awareness > Geography > Ocean-atmosphere interactions
General Awareness > Economy > Monsoon, agriculture and food inflation
With reference to 'Indian Ocean Dipole (IOD)' sometimes mentioned in the news while forecasting Indian monsoon, which of the following statements is/are correct? 1. IOD phenomenon is characterised by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean. 2. An IOD phenomenon can influence an El Nino's impact on the monsoon. Select the correct answer using the code given below:
Answer: 2 only
Sea surface temperature anomaly averaged over the central-eastern equatorial Pacific, the most commonly used measure of El Nino strength.
El Nino-Southern Oscillation, the coupled ocean-atmosphere cycle whose warm phase is El Nino and cool phase La Nina.
The sea surface temperature gradient between the western and eastern tropical Indian Ocean; its positive phase generally aids Indian monsoon rainfall.
Temperature departure from normal below the ocean surface, an early indicator of how much heat is available to sustain an El Nino.