La Nina Is Intact Now

Highlight: La Nina persists. Models show possible weak El Nino evolution possible in middle 2021.

Fig. 1: The 12-week Nino SSTA observations indicate La Nina continues.

Discussion: La Nina persists as September closes. The Nino SSTA regions are mostly within La Nina threshold except the central equatorial Pacific which stays marginally cool (Fig. 1). The eastern equatorial Pacific Ocean subsurface is quite cool and very supportive of maintaining La Nina (Fig. 2). A collection of dynamic and statistical ENSO forecast models using the Nino34 SSTA index indicates La Nina should peak late in 2020 and begin to weaken early next year and possibly reverse toward weak El Nino in middle 2021 (Fig. 3).

Fig. 2: The subsurface equatorial Pacific Ocean temperature anomalies are quite cool eastern sections and supportive of La Nina.

Fig. 3: A collection of Nino34 SSTA forecasts indicates La Nina ahead and peaking late in 2020 followed by a trend toward weak El Nino mid-next year.