El Nino Should Peak Next Month; Mature Phase Q1/2024  

Highlight: El Nino should peak next month, mature phase Q1/2024.  

Fig. 1-2: Upper ocean heat across the equatorial Pacific Ocean for last August and November (so far).

Discussion: Upper ocean heat across the equatorial Pacific Ocean was basin-wide in August featuring a peaking +5C anomaly off the northwest coast of South America (Fig. 1). Several months later in November (so far), the broad signature has constricted to near and east of the Dateline, typical of most El Nino episodes while the subsurface equatorial West Pacific cools (Fig. 2). The core of the subsurface warmth has shifted slightly westward, also indicated with the Nino SSTA regions as Nino12 (far East Pacific) cools and Nino34/Nino4 (East-central/Central Pacific) trend warmer (Fig. 3). The peak of El Nino 2023-24 is just ahead, during December while weakening into next spring follows and a potential La Nina emerges later next year (Fig. 4).

Fig. 2: The 12-week monitoring of the Nino SSTA regions.

Fig. 3: The NCEP CFS V2 Nino34 SSTA forecast through August 2024.