017
FXUS24 KWNC 111517
PMDENS
El Nino/Southern Oscillation (ENSO) Diagnostic Discussion
NWS Climate Prediction Center College Park MD
900 AM EDT Thu 10 Sep 2026

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

ENSO Alert System Status: El Nino Advisory

Synopsis: El Nino is strengthening, with a greater than
90percent chance of a very strong event during the Northern
Hemisphere fall and winter 2026-27.

El Nino strengthened further over the past month, with sea
surface temperature anomalies exceeding +3.0degC in the
eastern equatorial Pacific (Fig. 1). Except for the Nino-4
index, which decreased to +0.1degC in August, values in
the other Nino indices increased, reaching +1.8degC in
Nino-3.4, +2.5degC in Nino-3, and +3.4degC in Nino-1+2
(Fig. 2). The equatorial subsurface temperature index
(average from 180deg-100degW) remained steady during August
(Fig. 3), reflecting a deeper-than-average thermocline
(Fig. 4). Subsurface temperatures continued to be significantly
above average, with widespread anomalies in excess of +10.0degC
at depth. Low-level westerly wind anomalies and upper-level
easterly wind anomalies extended from the western to the
east-central equatorial Pacific. Enhanced convection and
rainfall persisted from the central to the eastern Pacific,
while anomalies remained suppressed over Indonesia (Fig. 5). The
traditional and equatorial Southern Oscillation indices remained
negative. Collectively, the coupled ocean-atmosphere system
reflected a strengthening El Nino.

The CPC Official ENSO outlook, which synthesizes multiple models
from North America and abroad, indicates El Nino will continue
to strengthen through the end of the year (Figs. 6-8). During
the October-December 2026 season, there is a 75percent chance of
a historic event that would exceed the strength of previous El
Nino events dating back to 1950 (+2.5degC or more for a 3-month
RONI value). With an event of this magnitude, the chances
of experiencing impacts consistent with El Nino are larger,
though not guaranteed (see CPC outlooks for probabilities of
seasonal anomalies). In summary, El Nino is strengthening,
with a greater than 90percent chance of a very strong event
during the Northern Hemisphere fall and winter 2026-27.

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). A probabilistic strength forecast is available
here. The next ENSO Diagnostics Discussion is scheduled for
8 October 2026. 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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