Although a weak La Niña was still apparent during January, below-average sea surface temperatures (SSTs) continued to weaken further across the equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño index values were mostly near -0.5°C, with the exception of Niño-1+2 which was +0.1°C [Fig. 2]. Like the surface, negative subsurface temperature anomalies continued to weaken [Fig. 3], with above-average subsurface temperatures expanding eastward at depth and near the surface of the eastern Pacific Ocean [Fig. 4]. Low-level easterly wind anomalies continued, but were confined to the western and central Pacific Ocean. Upper-level westerly wind anomalies were evident over the east-central Pacific. Suppressed convection persisted over the western and central tropical Pacific, while enhanced convection was observed over western Indonesia [Fig. 5]. Overall, the coupled ocean-atmosphere system continued to reflect La Niña.

The most recent IRI plume predicts a transition from La Niña to ENSO-neutral in the next couple of months [Fig. 6]. The forecaster consensus is largely in agreement. ENSO-neutral is expected to prevail during the spring and early summer. There are increasing chances of El Niño at longer forecast horizons, though uncertainty remains high because of the spring prediction barrier, which typically is associated with lower forecast accuracy. In summary, ENSO-neutral conditions are expected to begin within the next couple of months, and persist through the Northern Hemisphere spring and early summer [Fig. 7].

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 9 March 2023.

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