Forecast Forum
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
skill.
ENSO Alert System Status: Not Active
Outlook:
ENSO-neutral
conditions are favored to continue through at least the Northern Hemisphere
spring 2017, with increasing chances for El Niño development by late summer and
fall.
Discussion:
ENSO-neutral
conditions continued during March, with near-average sea surface temperatures
(SSTs) across the central equatorial Pacific and above-average SSTs in the
eastern Pacific (Fig. T18). The latest monthly Niño index
values were near zero in the Niño-4 and Niño-3.4 regions, and +0.5 and +2.0°C
farther east in the Niño-3 and Niño-1+2 regions, respectively (Table T2). The upper-ocean heat content anomaly,
averaged across the central and eastern Pacific, decreased to near zero during
March, a reflection of above-average temperatures at depth in the east offset
by below-average temperatures in the central Pacific (Fig. T17). Atmospheric
convection remained suppressed over the central tropical Pacific and enhanced
over the Maritime Continent (Fig. T25). The low-level easterly winds were
enhanced over the central and western tropical Pacific, and weaker than average
over the eastern Pacific. Also, upper-level westerly
winds were anomalously easterly over the western and far eastern Pacific (Fig. T20 & Fig. T21),
while the Southern Oscillation Index was near average. Overall, the ocean and
atmosphere system is consistent with ENSO-neutral conditions.
Most models predict the continuation of ENSO-neutral
(3-month average Niño-3.4 index between -0.5°C and 0.5°C) through the late
Northern Hemisphere spring (April-June; Figs.
F1-F12).
However, at least one-half of the dynamical model forecasts, including the NCEP
CFSv2, anticipate an onset of El Niño as soon as the April-June season. Because
of typically lower skill in forecasts made at this time of the year, and the
lingering La Niña-like tropical convection and wind patterns over the western
half of the Pacific basin, the forecaster consensus favors ENSO-neutral during
April-June with a 60-65% chance. Thereafter, there are increasing odds for El
Niño toward the second half of 2017 (~50% chance from approximately
August-December). In summary, ENSO-neutral conditions are favored to continue
through at least the late Northern Hemisphere spring 2017, with increasing
chances for El Niño development by late summer and fall
Weekly
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).