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: Not Active
is favored through Northern Hemisphere spring 2020 (~60% chance), continuing
through summer 2020 (~50% chance).
During December 2019, near-to-above-average sea surface temperatures (SSTs) were
evident over the equatorial Pacific Ocean (Fig.
T18). The eastern Niño-1+2 and Niño-3 regions were
near average (+0.3°C), while the Niño-4 and Niño-3.4 regions were warmer at
+0.5°C and +1.0°C, respectively (Table T2).
Equatorial subsurface temperature anomalies increased during the month (averaged
across 180°-100°W), reflecting a downwelling Kelvin
wave, which was evident in the above-average temperatures in the central and
east-central Pacific Ocean (Fig. T17).
Over the month, westerly wind anomalies persisted over small regions of
the western and eastern equatorial Pacific Ocean (Fig. T20), while upper-level
winds were near average over most of the equator (Fig. T21). Tropical convection remained suppressed over
Indonesia and east of the Date Line, and was enhanced to the west of the Date
Line (Fig. T25).
The overall oceanic and atmospheric system was consistent with
ENSO-neutral, though recent observations reflected a trend toward warmer
conditions that will be monitored.
majority of models in the IRI/CPC plume (Figs.
F1-F12) continue to mostly favor ENSO-neutral (Niño-3.4 index between
-0.5°C and +0.5°C) through the Northern Hemisphere summer. For the December 2019-February 2020 season,
the Niño-3.4 index is predicted to be near +0.5°C, which is consistent with the
latest observations. The forecasters
also favor above-average ocean temperatures to continue in the next month or
two, but, in alignment with most model guidance, do not foresee a continuation
over several consecutive seasons or shifts in the atmospheric circulation that
would indicate El Niño. In summary, ENSO-neutral is favored through Northern
Hemisphere spring 2020 (~60% chance), continuing through summer 2020 (~50%
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).