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 (CFS03) 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 using linear inverse modeling (Penland and Magorian 1993: J.
Climate, 6, 1067‑1076) are shown in Figs. F9 and F10. Predictions from the Scripps / Max Planck
Institute (MPI) hybrid coupled model (Barnett et al. 1993: J. Climate, 6,
1545‑1566) are shown in Fig. F11.
Predictions from the ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea.
Forecasting, 12, 633‑652) are shown in Fig. F12. Niño 3.4 predictions are summarized in Fig.
F13, 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
ENSO Alert System Status: El Niño Watch
Niño is expected to form and continue through the Northern Hemisphere winter 2018-19
(~80% chance) and into spring (55-60% chance).
continued during October, despite widespread above-average sea surface
temperatures (SSTs) across the equatorial Pacific Ocean (Fig. T18). All four Niño
regions showed increased SST anomalies in October, with the monthly values near
+1.0°C in the Niño-4, Niño-3.4 and Niño3 regions, and +0.4°C in the Niño-1+2 region (Table T2). Positive subsurface temperature
anomalies (averaged across 180°-100°W) also continued, due to the persistence
of above-average temperatures at depth across the eastern half of the
equatorial Pacific Ocean (Fig. T17). However, atmospheric convection
remained slightly suppressed near the Date Line and over Indonesia (Fig. T25).
Low-level westerly wind anomalies were observed over the eastern Pacific during October (Fig. T20), while weak upper-level westerly
wind anomalies were present over the far western Pacific (Fig. T21). The traditional
and equatorial Southern Oscillation indices were near zero (Table T1
and Fig. T2). Despite the above-average ocean
temperatures across the equatorial Pacific Ocean, the overall coupled
ocean-atmosphere system continued to reflect ENSO-neutral.
The majority of models in the IRI/CPC plume predict a
Niño3.4 index of +0.5°C or greater to continue through the rest of the fall
and winter and into spring (Figs. F1-F13). The
official forecast favors the formation of a weak El Niño, with the expectation
that the atmospheric circulation will eventually couple to the anomalous
equatorial Pacific warmth. In summary,
El Niño is expected to form and continue through the Northern Hemisphere winter
2018-19 (~80% chance) and into spring (55-60% chance).
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).