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 ENSO‑CLIPER
statistical model (Knaff and Landsea 1997, Wea. Forecasting, 12, 633‑652)
are shown in Fig. F11. Niño 3.4
predictions are summarized in Fig. F12, 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: Final El Niño Advisory
El Niño has
transitioned to ENSO-neutral, which is most likely to continue through Northern
Hemisphere winter 2019-20 (50-55% chance).
July, ENSO-neutral conditions were reflected by the combination of
below-average sea surface temperatures (SSTs) in the eastern equatorial Pacific
Ocean and above-average SSTs in the central Pacific (Fig. T18). The monthly ENSO
indices were +0.9°C, +0.4°C, 0.1°C and -0.3°C in the Niño-4, Niño-3.4, Niño-3 and Niño-1+2 regions, respectively (Table T2).
Upper-ocean subsurface temperatures (averaged across 180°-100°W) were near
average throughout the month, as anomalously cool waters prevailed
in the eastern Pacific and anomalously warm waters continued in the central
Pacific (Fig. T17).
Suppressed tropical convection continued over Indonesia, while
near-average convection was observed near the Date Line (Fig. T25). Low-level wind anomalies were near average
over the tropical Pacific Ocean (Fig. T20), and upper-level winds were
easterly over the east-central Pacific (Fig.
T21). The traditional and equatorial
Southern Oscillation Indices remained slightly negative (Figs. T1, T2). Overall, oceanic and atmospheric
conditions were consistent with a transition to ENSO-neutral.
of the Niño-3.4 index (Figs. F1-F12)
favors ENSO-neutral (Niño-3.4 index between -0.5°C and +0.5°C), with index values greater than zero from late
Northern Hemisphere summer into fall, warming closer to the El Niño threshold
(+0.5°C) by winter. Atypically,
dynamical models forecast weaker positive SST anomalies than statistical models
throughout most of the forecast period.
As a result, while forecasters favor ENSO-neutral conditions, the odds
of El Niño (~30%) are roughly twice that of La Niña for next winter. In summary,
El Niño has transitioned to ENSO-neutral,
which is most likely to continue through Northern Hemisphere winter 2019-20 (50-55%
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).