NOAA Confirms the Start of El Niño, Says Meteorological Bulletin from SC, June 11

The U.S. National Oceanic and Atmospheric Administration (NOAA) confirmed on June 11, 2026, the start of El Niño after months of monitoring conditions in the equatorial Pacific Ocean. The confirmation came once sea surface temperature anomalies in the equatorial Pacific exceeded +0.5°C and the tropical atmosphere showed a response consistent with the phenomenon. At the moment, El Niño is still weak, but it is expected to strengthen over the coming months.

According to NOAA, there is a 63% chance that between November and January the event will reach “very strong” intensity, with anomalies above +2.0°C. That would mark an increase from earlier forecasts and, if confirmed, could make this one of the most intense El Niño events observed since 1950. Such strong episodes are commonly referred to as “Super El Niño.” However, Santa Catarina’s civil defense agency notes that the size of the impacts does not depend only on oceanic intensity. It also depends on atmospheric conditions during each rainfall episode and on the vulnerability of each affected region.

El Niño is not only an oceanic event, but the result of interaction between the ocean and the atmosphere. The warming of the equatorial Pacific changes wind patterns and triggers effects in different parts of the world. In Brazil, the best-known impacts are usually reduced rainfall in parts of the North Region and more frequent and heavier precipitation in the South Region.

Monitoring of the phenomenon is carried out using different areas of the equatorial Pacific. The central Niño 3.4 region is the main reference used by international meteorological centers to monitor and classify El Niño. This is important because some areas of the Pacific may warm faster than others, which can create apparently conflicting reports about the strength of the warming. The most widely accepted technical criterion still relies primarily on anomalies observed in the Niño 3.4 region.

An El Niño condition is considered present when sea surface temperatures in Niño 3.4 are at least 0.5°C above the climatological average. Traditionally, a consolidated El Niño is classified only after the warming persists for at least five consecutive trimesters, a retrospective criterion used for climate classification. Operational monitoring, however, does not require waiting that long. Instead, it looks at three main factors: temperatures at or above +0.5°C in Niño 3.4, consistent atmospheric response, and forecasts showing that these conditions will continue in the coming months.

For Santa Catarina, the main effects of El Niño are usually felt during spring, especially in September, October and November. Forecasts for this year suggest the event will gain strength in the next few months and peak between spring and summer. Since the local climate already favors rainfall during that period, El Niño may further intensify precipitation and related impacts. Authorities advise the public to follow weather updates and official alerts from Santa Catarina’s civil defense agency.