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
(CFSv2) 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 from the ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea.
Forecasting, 12, 633‑652) are shown in Fig. F9. Niño 3.4 predictions are summarized in Fig.
F10, 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: La Niña Advisory
Outlook:
There is a 75% chance of La
Niña during the Northern Hemisphere winter (December-February) 2022-23, with a
54% chance for ENSO-neutral in February-April 2023.
Discussion:
Below-average
sea surface temperatures (SSTs) continued across the central and eastern
equatorial Pacific Ocean during September (Fig.
T18). Most of the Niño indices
decreased last month, with the latest index values spanning -0.8C to -1.1C (Table T2).
For the last couple months, negative subsurface temperature anomalies remained
mostly unchanged, reflecting the persistence of below-average temperatures
across the eastern Pacific Ocean (Fig. T17).
Low-level easterly wind anomalies and upper-level westerly wind
anomalies prevailed across most of the equatorial Pacific (Figs. T20 & T21).
Convection was suppressed over the western and central tropical Pacific
and was enhanced over Indonesia (Fig. T25). Overall, the coupled
ocean-atmosphere system continued to reflect La Niña.
The
most recent IRI plume forecast of the Niño-3.4 SST index indicates La Niña will
persist into the Northern Hemisphere winter 2022-23, and then transition to ENSO-neutral
in January-March 2023 (Figs. F1-F12).
The forecaster consensus for this month
favors a slightly later transition to ENSO-neutral, during February-April 2023,
which is consistent with the latest North American Multi-Model Ensemble (NMME). However, predicting the timing of transitions
is challenging, and there continues to be uncertainty over how long La Niña may
last. In summary, there is a 75% chance
of La Niña during the Northern Hemisphere winter (December-February) 2022-23,
with a 54% chance for ENSO-neutral in February-April 2023.
Weekly
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).