ENSO Alert System Status: La Niña Advisory

Synopsis:  La Niña is likely to continue through the Northern Hemisphere winter 2020-21 (~95% chance during January-March) and into spring 2021 (~65% chance during March-May).

La Niña strengthened during October, as indicated by well below-average sea surface temperatures (SSTs) extending from the Date Line to the eastern Pacific Ocean [Fig. 1]. The SST indices in the two westernmost Niño regions, Niño-4 and Niño-3.4 cooled further from last month, and the Niño-3.4 index was -1.5°C in the past week [Fig. 2]. The equatorial subsurface temperature anomalies (averaged from 180°-100°W) also became colder [Fig. 3], and continue to reflect below-average temperatures from the surface to 200m depth in the eastern Pacific Ocean [Fig. 4]. The atmo