El-NINO UPDATE

EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION

EXPECTED ENSO CONDITIONS GOING FORWARD

A transition from La Niña to ENSO-neutral is expected in February-April 2026 (60% chance), with ENSO-neutral likely persisting through the Northern Hemisphere summer (56% chance in June-August 2026).

Synopsis:  A transition from La Niña to ENSO-neutral is expected in the next month, with ENSO-neutral favored through May-July 2026 (55% chance). In June-August 2026, El Niño is likely to emerge (62% chance) and persist through at least the end of 2026.

March-12-2026. El Nino La Nina ENSO update.

La Niña continued in February 2026, with below-average sea surface temperatures (SSTs) persisting in the east-central equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño-3.4 index value was -0.5°C, with the westernmost (Niño-4) and easternmost (Niño-1+2) indices at -0.2°C and +0.6°C, respectively [Fig. 2]. The equatorial subsurface temperature index (average from 180°-100°W) continued to increase [Fig. 3], reflecting the strengthening of above-average subsurface temperatures across the Pacific [Fig. 4]. Over the east-central equatorial Pacific, low-level wind anomalies were easterly, while upper-level wind anomalies were westerly. Convection was suppressed over the Date Line and convection was enhanced over Indonesia [Fig. 5]. The traditional and equatorial Southern Oscillation indices were positive. Collectively, the coupled ocean-atmosphere system remained consistent with La Niña.

The North American Multi-Model Ensemble (NMME) average, including the NCEP CFSv2 [Fig. 6], points toward ENSO-neutral through the late Northern Hemisphere Spring 2026, with a transition to El Niño thereafter. Even though model forecasts are relatively less accurate this time of year, the increasing odds of El Niño are supported by the large amount of heat in the subsurface ocean and the expected weakening of the low-level trade winds. If El Niño forms, the potential strength remains very uncertain, with a 1-in-3 chance that it would be “strong” during October-December 2026 (Niño-3.4 ≥ +1.5°C). In summary, a transition from La Niña to ENSO-neutral is expected in the next month, with ENSO-neutral favored through May-July 2026 (55% chance). In June-August 2026, El Niño is likely to emerge (62% chance) and persist through at least the end of 2026 [Fig. 7].