Forecast Forum

The canonical correlation analysis (CCA) forecast of SST in the central Pacific (Barnett et al. 1988, Science, 241, 192‑196; Barnston and Ropelewski 1992, J. Climate, 5, 1316‑1345), is shown in Figs. F1 and F2. This forecast is produced routinely by the Prediction Branch of the Climate Prediction Center. The predictions from the National Centers for Environmental Prediction (NCEP) Coupled Forecast System Model (CFSv2) are presented in Figs. F3 and F4a, F4b.  Predictions from the Markov model (Xue, et al. 2000: J. Climate, 13, 849‑871) are shown in Figs. F5 and F6.   Predictions from the latest version of the LDEO model (Chen et al. 2000: Geophys. Res. Let., 27, 2585‑2587) are shown in Figs. F7 and F8.  Predictions from the ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea. Forecasting, 12, 633‑652) are shown in Fig. F9.  Niño 3.4 predictions are summarized in Fig. F10, provided by the Forecasting and Prediction Research Group of the IRI.

The CPC and the contributors to the Forecast Forum caution potential users of this predictive information that they can expect only modest skill.

 

ENSO Alert System Status: Final La Niña Advisory

 

Outlook:

 

La Niña has ended and ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring and early summer 2023.

 

Discussion:

 

During February 2023, below-average sea surface temperatures (SSTs) weakened and currently persist only in the central Pacific Ocean (Fig. T18). The latest monthly Niño-3.4 index value was -0.4C (Table T2).  In contrast to the central Pacific, SSTs in parts of the eastern Pacific Ocean were above average, with the latest Niño-1+2 index value at +0.7C.  In the last month, area-averaged subsurface temperatures became slightly above average, with positive temperature anomalies spanning the Pacific, though remaining mostly at depth (Fig. T17).  The atmospheric circulation anomalies across the tropical Pacific are lagging the changes in the ocean.  Low-level easterly wind anomalies continue over the central Pacific Ocean (Fig. T20). Upper-level westerly wind anomalies were evident over most of the Pacific (Fig. T21). Suppressed convection persisted over the central tropical Pacific, while enhanced convection was observed over Indonesia (Fig. T25). Collectively, the coupled ocean-atmosphere system was consistent with ENSO-neutral.

The most recent IRI plume favors ENSO-neutral to continue through the spring, with El Niño forming during summer 2023 and persisting through the fall (Figs. F1-F12).  In contrast, the forecaster consensus favors ENSO-neutral through summer 2023, with elevated chances of El Niño developing afterwards.  The smaller chances of El Niño relative to the model predictions are primarily because ENSO forecasts made during the spring are less accurate, and also the tropical Pacific atmosphere is still fairly consistent with a cool/La Niña-like state.  However, it is possible that strong warming near South America may portend a more rapid evolution toward El Niño and will be closely monitored.  In summary, La Niña has ended and ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring and early summer 2023.

Weekly updates of oceanic and atmospheric conditions are available on the Climate Prediction Center homepage (El Niño/La Niña Current Conditions and Expert Discussions).