Early 2019 ENSO Trend is Away from El Nino, But…

Emerging warm SSTA in the middle latitude southern hemisphere
01/30/2019, 5:45 pm EDT
Introducing Atmospheric River Index
02/06/2019, 2:38 pm EDT
Show all

ENSO is now in neutral phase. However, resurgent warming has appeared near the Dateline. If that warmth shifts eastward which is likely then another El Nino onset risk redevelops during upcoming spring season.

Discussion: The NINO SSTA regions each cooled significantly during January as the trend toward El Nino backed off. The atmosphere continues to have difficulty engaging marginal warmth of the eastern equatorial Pacific to cause trade winds to ease, sea level pressure to lower and anomalous convection to form.

The subsurface in the eastern equatorial Pacific also cooled indicating limited fuel to cause El Nino onset. However, new warmth is gathering near the Dateline. If the new warmth in central equatorial Pacific shifts east a new attempt at El Nino development will emerge in April or May.

Fig. 1: The 12-week Nino SSTA observations indicate a cooler trend.

Fig. 2: The subsurface equatorial Pacific has cooled in early 2018.

Fig. 3: Pacific basin-wide upper ocean heat diminished in January.