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 Climate Prediction Center. The predictions from the 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: La Niña Advisory

 

Outlook:

 

A transition from La Niña to ENSO-neutral is anticipated during the February-April 2023 season. By Northern Hemisphere spring (March-May 2023), the chance for ENSO-neutral is 82%. 

 

Discussion:  

 

During December, below-average sea surface temperatures (SSTs) weakened over the equatorial Pacific Ocean (Fig. T18).  Except for Niño1+2, all of the monthly Niño index values were between -0.7C and -0.8C (Table T2).  The subsurface temperature anomalies also weakened substantially, but below-average subsurface temperatures persisted near the surface and at depth in the eastern equatorial Pacific Ocean (Fig. T17).  However, the atmospheric circulation anomalies over the tropical Pacific Ocean did not notably weaken.  Low-level easterly wind and upper-level westerly wind anomalies remained across most of the equatorial Pacific (Figs. T20 & T21). Suppressed convection persisted over the western and central tropical Pacific, while enhanced convection was observed around Indonesia (Fig. T25). Overall, the coupled ocean-atmosphere system continued to reflect La Niña.

The most recent IRI plume predicts that La Niña will transition to ENSO-neutral during the Northern Hemisphere winter 2022-23 (Figs. F1-F12).  Interestingly, the dynamical models indicate a faster transition (January-March) than the statistical models (February-April).  At this time, the forecaster consensus favors the statistical models, with a transition to ENSO-neutral in the February-April 2023 season.  The sustained atmospheric circulation anomalies and the weakening downwelling oceanic Kelvin wave do not support an imminent transition.  However, lower accuracy during times of transition, and when predictions go through the spring, means that uncertainty remains high.  In summary, a transition from La Niña to ENSO-neutral is anticipated during the February-April 2023 season.  By Northern Hemisphere spring (March-May 2023), the chance for ENSO-neutral is 82%.

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