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: El Niño Advisory

 

Outlook: There is a greater than 90% chance that El Niño will continue through the Northern Hemisphere winter.

 

Discussion:

 

In June, a weak El Niño was associated with above-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean (Fig. T18). Nearly all of the monthly Niño indices were near or in excess of +1.0C, Niño-3.4 was +0.9C, Niño-3 was +1.2C, and Niño1+2 was +2.6C (Table T2). Area-averaged subsurface temperatures anomalies increased compared to May, with positive anomalies below the surface of the equatorial Pacific Ocean (Fig. T17). In contrast, the tropical atmospheric anomalies were weaker compared to the oceanic anomalies. For the June monthly average, low-level winds were near average over most of the equatorial Pacific (Fig. T20). Upper-level wind anomalies were easterly over the western Pacific and westerly over the eastern Pacific (Fig. T21). Convection and rainfall were enhanced around the International Date Line and were weakly suppressed in the vicinity of Indonesia (Fig. T25). The equatorial SOI remained negative (0.5 standard deviations below average), while the traditional, station-based SOI was near zero (Figs. T1 & T2).  Collectively, the coupled ocean-atmosphere system reflected a weak El Niño.

The most recent IRI plume indicates El Niño will persist through the Northern Hemisphere winter 2023-24 (Figs. F1-F12).  Forecasters favor continued growth of El Niño through the fall, peaking this winter with moderate-to-strong intensity (81% chance of November-January Niño-3.4 >= 1.0C).  An event that becomes “historically strong” (seasonally averaged Niño-3.4 >= 2.0C), rivaling the winters of 1997-98 or 2015-16, has an approximately 1 in 5 chance.  In summary, there is a greater than 90% chance that El Niño will continue through the Northern Hemisphere winter.

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