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: El Niño is anticipated to continue through the Northern Hemisphere winter (with greater than 95% chance through December 2023 -February 2024).

 

Discussion:

 

In July, El Niño continued as indicated by above-average sea surface temperatures (SSTs) across the equatorial Pacific Ocean (Fig. T18).  Nearly all of the monthly Niño indices in the central and eastern Pacific were in excess of +1.0C: Niño-3.4 was +1.1C, Niño-3 was +1.6C, and Niño1+2 was +3.2C (Table T2).  Area-averaged subsurface temperatures anomalies decreased compared to June, but remained positive, in association with anomalous warmth across the equatorial Pacific Ocean (Fig. T17).  Tropical atmospheric anomalies were also consistent with El Niño.  Starting in mid-July, low-level winds were anomalously westerly over the western equatorial Pacific, while anomalous easterlies prevailed over the eastern Pacific (Fig. T20). Upper-level wind anomalies were westerly over the eastern Pacific (Fig. T21).  Convection continued to be enhanced around the International Date Line and was weakly suppressed in the vicinity of Indonesia (Fig. T25). The equatorial Southern Oscillation Index (SOI) and the traditional SOI were both negative (Figs. T1 & T2).  Collectively, the coupled ocean-atmosphere system reflected El Niño.

The most recent IRI plume indicates El Niño will persist through the Northern Hemisphere winter 2023-24 (Figs. F1-F12).  Given recent developments, forecasters are more confident in a “strong” El Niño event, with roughly 2 in 3 odds of an event reaching or exceeding 1.5C for the November-January seasonal average in Niño-3.4.  Note that a strong El Niño does not necessarily equate to strong El Niño impacts locally, with the odds of related climate anomalies often lower than the chances of El Niño itself (e.g., CPC’s seasonal outlooks).  In summary, El Niño is anticipated to continue through the Northern Hemisphere winter (with greater than 95% chance through December 2023 -February 2024).

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