La Nina Modoki Developing; El Nino to follow?

Fig. 1: The daily tropical Pacific Ocean SSTA analysis reveals La Nina Modoki while the eastern equatorial Pacific Ocean warms dramatically.

Discussion: During recent weeks and particularly in February, the Nino3 SSTA region located in the eastern equatorial Pacific Ocean has warmed significantly while near the Dateline, La Nina cool waters persist. The difference between the two regions implies the 2024-25 La Nina episode has shifted west toward the Dateline (Fig. 1) implying formation of La Nina Modoki (Fig. 2). Meanwhile, vigorous warming has taken place in the eastern tropical Pacific especially off the northwest coast of South America where SSTA is +1.66 (Fig. 3) and a robust +2.07C change during the past 30 days (Fig. 4). The subsurface equatorial Pacific east of the Dateline is warming rapidly (Fig. 5). Overall, while La Nina has shifted toward the Dateline, macro-scale conditions indicate La Nina may dissipate quickly during northern hemisphere meteorological spring. The previously indicated El Nino forecast issued by ECMWF for 2025 is beginning to look reliable (Fig. 6).

Fig. 2: The Climate Impact Company ENSO East-West Index identifies presence of Modoki conditions. Due to the much warmer Nino3 vs. Nino4 region, a La Nina Modoki has developed.

Fig. 3-4: The Nino12 SSTA region daily SSTA analysis and 30-day change.

Fig. 5: Upper ocean heat anomalies east of the Dateline for the past one year.

Fig. 6: The ECMWF El Nino forecast for 2025 is starting to look reliable.