090
FXUS24 KWNC 091401
PMDENS
El Nino/Southern Oscillation (ENSO) Diagnostic Discussion
NWS Climate Prediction Center College Park MD
900 AM EST Thu 09 Jan 2025

NOTE: figures mentioned in the discussion are available on
the internet at HTTP://WWW.CPC.NCEP.NOAA.GOV

ENSO Alert System Status: La Nina Advisory

Synopsis: La Nina conditions are present and are expected
to persist through February-April 2025 (59percent chance),
with a transition to ENSO-neutral likely during March-May 2025
(60percent chance).

La Nina conditions emerged in December 2024 and were reflected
in below-average sea surface temperatures (SSTs) across the
central and east-central equatorial Pacific Ocean (Fig. 1).
The latest weekly indices were -0.7degC in Nino-3.4 and
-0.6degC in Nino-4, with values close to zero in Nino-1+2 and
Nino-3 (Fig. 2). Subsurface cooling in the equatorial Pacific
Ocean strengthened significantly (Fig. 3), with below-average
temperatures dominating the central and eastern equatorial
Pacific Ocean (Fig. 4). Low-level wind anomalies were easterly
over the western and central Pacific, while upper-level wind
anomalies were westerly over the central and eastern Pacific.
Convection was suppressed over the Date Line and was enhanced
over Indonesia (Fig. 5). The traditional and equatorial
Southern Oscillation indices were positive. Collectively, the
coupled ocean-atmosphere system indicated La Nina conditions.

The dynamical models in the IRI plume continue to predict a weak
La Nina during the winter seasons, as indicated by the Nino-3.4
index values less than -0.5degC (Fig. 6). The North American
Multi-Model Ensemble (NMME) predicts slightly cooler SST
anomalies with La Nina persisting through February-April 2025.
The forecast team favors the NMME guidance, predicting weak La
Nina conditions through the early spring before transitioning
to ENSO-neutral. Weak La Nina conditions are less likely to
result in conventional winter/spring impacts, though predictable
signals can still influence the forecast guidance (e.g.,
CPC`s seasonal outlooks). In summary, La Nina conditions are
present and are expected to persist through February-April 2025
(59percent chance), with a transition to ENSO-neutral likely
during March-May 2025 (60percent chance; Fig. 7).

This discussion is a consolidated effort of the National
Oceanic and Atmospheric Administration (NOAA), NOAA`s National
Weather Service, and their funded institutions. Oceanic and
atmospheric conditions are updated weekly on the Climate
Prediction Center website (El Nino/La Nina Current Conditions
and Expert Discussions). Additional perspectives and analyses
are also available in an ENSO blog. A probabilistic strength
forecast is available here. The next ENSO Diagnostics
Discussion is scheduled for 13 February 2025. To receive
an e-mail notification when the monthly ENSO Diagnostic
Discussions are released, please send an e-mail message to:
ncep.list.enso-update@noaa.gov.



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