La Nina Trend Weaker and That Trend is Likely to Continue

Discussion: During the past week the temperature anomaly trend in the equatorial Pacific Ocean subsurface was slightly warmer near 100 meters and lower especially in the East Pacific in the 150-450-meter range (Fig. 1). The warm Kelvin Waver centered at the Dateline at 150-meter depth remains quite strong but unchanged in strength during mid-to-late May. The cool waters sustaining La Nina in the upper 100 meters of the equatorial Pacific are trending less cool. Consequently, the Nino SSTA regions are also slightly less cool during the past week as a moderate strength La Nina has weakened slightly (Fig. 2). The NCEP CFS V2 Nino34 forecast now indicates a very weak La Nina for 2022 likely ending as meteorological winter 2022-23 arrives (Fig. 3).

Fig. 1: The equatorial Pacific Ocean subsurface temperature anomalies.

Fig. 2: The 12-week Nino SSTA observations.

Fig. 3: Latest NCEP CFS V2 Nino34 SSTA forecast.