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: Not Active
is favored (~50 to 55% chance) into the Northern Hemisphere winter 2017-18.
June, ENSO-neutral continued, although equatorial sea surface temperatures
(SSTs) remained above average in the central and east-central Pacific Ocean (Fig. T18).
The monthly Niño index values were +0.6°C in the Niño-4 and Niño-3.4 regions,
and closer to zero in the Niño-3 and Niño-1+2 regions (Table T2). The upper-ocean
heat content anomaly was above average during June, reflecting above-average sub-surface
temperatures across the central and eastern Pacific (Fig. T17). In the atmosphere,
tropical convection was suppressed over the west-central tropical Pacific and enhanced
over the Maritime Continent (Fig. T25). The lower-level and upper-level
winds were near average over most of the tropical Pacific (Fig. T20 & Fig. T21), and the Southern Oscillation Index (SOI) and
Equatorial SOI were slightly negative to near-zero (Tables T1 & T2).
Overall, the ocean and atmosphere system remains consistent with
models predict the onset of El Niño (3-month average Niño-3.4 index at or
greater than 0.5°C) during the Northern Hemisphere summer (Figs. F1-F13). However, more than half of the models favor
ENSO-neutral through the remainder of 2017. These predictions, along with the
near-average atmospheric conditions over the Pacific, lead forecasters to favor
ENSO-neutral into the winter (~50 to
55% chance). However, chances for El Niño remain elevated (~35-45%)
relative to the long-term average. In summary, ENSO-neutral is favored (~50 to 55% chance) into the Northern Hemisphere winter
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).