Recent observations from the National Oceanic and Atmospheric Administration (NOAA) of sea surface temperature (SST) anomalies in February 2024 indicate a weakening El Niño across most of the equatorial Pacific Ocean. Notably, a small region in the eastern equatorial Pacific (~100°W) has started showing below-average SSTs. The latest Niño-3.4 index stood at 1.4°C, signaling a weakening trend but still in positive territory. Subsurface temperature anomalies were slightly negative, influenced by an upwelling Kelvin wave bringing cooler temperatures to the equatorial Pacific.
Atmospheric conditions, including low-level and upper-level winds, have been near average or showed easterly anomalies in the east-central Pacific. Enhanced convection was observed near the Date Line, while Indonesia experienced suppressed convection. These patterns collectively suggest the ongoing El Niño event is diminishing.
The latest forecasts from the International Research Institute for Climate and Society (IRI) indicate a shift towards ENSO-neutral conditions during spring 2024, with the possibility of La Niña developing in the summer. Forecasts based on dynamical models, considered slightly more accurate at this time of year, favor the development of La Niña. Despite the inherent uncertainty in spring forecasts, historical patterns suggest a strong likelihood of La Niña following major El Niño events.
As of now, the likelihood of transitioning to ENSO-neutral conditions by April-June 2024 stands at 83%, with a 62% chance of La Niña development by June-August 2024.
This analysis is a collaborative effort by the NOAA, NOAA's National Weather Service, and affiliated institutions. These organizations provide weekly updates on oceanic and atmospheric conditions, with further insights available on the Climate Prediction Center website and through an ENSO blog. A probabilistic strength forecast is also accessible. The next comprehensive ENSO Diagnostics Discussion is scheduled for April 11,
