ENSO Tracker - Oct 2022

Sea surface temperature (SST) forecasts for Nov 2022 – Jan 2023 call for cooler than average conditions across most of the equatorial Pacific (Fig. 1), and the current 3.4/4 anomalies are below the La Niña threshold (Fig. 2). ENSO outlooks generally call for La Niña to last well into winter, but most forecasts highlight a return to ENSO-neutral conditions in early 2023.

Forecast Roundup: On Oct 11 the Australian Bureau of Meteorology highlighted an ongoing La Niña event, noting “atmospheric and oceanic indicators…are consistent with an established La Niña” and noted a likely return to ENSO-neutral conditions by early 2023. On Oct 11 the Japanese Meteorological Agency (JMA) observed ongoing La Niña conditions that had a 90-percent chance of continuing into early winter, and a 60-percent chance through the end of winter. On Oct 12 the NOAA Climate Prediction Center (CPC) maintained their “La Niña Advisory” noting “the coupled ocean-atmosphere system continued to reflect La Niña” and called for a 75-percent chance of La Niña through winter and a 54-percent chance of ENSO-neutral in Feb-Apr 2023. On Oct 13, the International Research Institute (IRI) issued an ENSO Quick Look (Fig. 3), noting “oceanic and atmospheric variables have remained consistent with La Niña” with increasing signs of a transition to ENSO neutral by end of winter. The North American Multi-Model Ensemble (solid and dashed black line, Fig. 4) is currently forecast to remain under the La Niña temperature threshold through fall and well into winter.

Summary: The triple dip La Niña may be short-lived, with forecasts for a return to ENSO-neutral in early 2023. La Niña typically brings below-average precipitation to the Southwest, but if the La Niña conditions return to ENSO-neutral before winter is over, it will be interesting to see if this has any bearing on cumulative winter precipitation totals (i.e. is there a chance of normal precipitation in late winter and early spring that might offset any early season deficits resulting from the influence of La Niña).

Online Resources

Figure 1 - Australian Bureau of Meteorology - bom.gov.au/climate/enso
Figure 2 - NOAA - Climate Prediction Center - cpc.ncep.noaa.gov
Figure 3 - International Research Institute for Climate and Society - iri.columbia.edu
Figure 4 - NOAA - Climate Prediction Center - cpc.ncep.noaa.gov