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
ENSO-neutral is favored (~85% chance during Jul-Sep, decreasing to ~55%
during Dec-Feb) through the Northern Hemisphere winter 2017-18.
During July, ENSO-neutral continued, as equatorial sea
surface temperatures (SSTs) were near average across most of the Pacific Ocean
(Fig. T18). The monthly Niño SST index values
were between 0.4ºC and -0.1ºC in all four Niño regions (Table T2), having recently decreased from higher levels. The
upper-ocean heat content anomaly was near average during July, reflecting
below-average temperatures along the thermocline across the central and eastern
Pacific overlain by slightly above-average temperatures (Fig. T17). Tropical convection was near average over the
eastern half of the Pacific and enhanced over the western Pacific and the
Maritime Continent (Fig. T25). The lower-level trade winds were
slightly enhanced near the International Date Line,
and upper-level winds were near average over most of the tropical Pacific (Fig. T20 & Fig. T21). Overall, the ocean and atmosphere
system remains consistent with ENSO-neutral.
The majority of models favor ENSO-neutral through the
remainder of 2017 (Figs. F1-F13). These predictions, along with the demise of the
recent Pacific warmth and continued near-average atmospheric conditions over
the Pacific, lead forecasters to favor ENSO-neutral through the winter.
However, some chance for El Niño (15-20%) or La Niña (25-30%) remains during
the winter. Also, ENSO-neutral conditions are predicted for the upcoming peak
months (August-October) of the Atlantic hurricane season. In summary,
ENSO-neutral is favored (~85% chance during Jul-Sep, decreasing to ~55% during
Dec-Feb) through the Northern Hemisphere winter 2017-18.
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).