ENSO Tracker - Jul 2022
Sea surface temperature (SST) forecasts for Aug – Oct 2022 still indicate cool conditions across most of the equatorial Pacific (Fig. 1). Current 3.4/4 anomalies remain below the La Niña threshold but have moved closer to neutral in the last few months (Fig. 2). ENSO outlooks generally see La Niña lasting through summer and into fall.
Forecast Roundup: On Jul 7 the Australian Bureau of Meteorology ENSO outlook continued on a La Niña watch, noting an increased chances of La Niña compared to normal, with a mix of neutral and La Niña indicators in the ocean and atmosphere, respectively. On Jul 11 the Japanese Meteorological Agency (JMA) observed La Niña conditions had a 60-percent chance of continuing through autumn, and a 40-percent chance of returning to ENSO-neutral during summer. On Jul 14 the NOAA Climate Prediction Center (CPC) maintained their “La Niña Advisory” noting “the coupled ocean-atmosphere system was consistent with La Niña conditions” and called for a 60-percent chance of La Niña in the short term (Jul-Sept), and a 62- to 66-percent chance of La Niña in fall and early winter. On Jul 19, the International Research Institute (IRI) issued an ENSO Quick Look (Fig. 3), noting below-average SSTs, with most models indicating they will remain in La Niña territory into fall and early 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 into winter.
Summary: The outlooks are slightly more certain in the possibility of La Nina extending through summer and into fall and winter, with each month providing a clearer picture of the short term forecast. Assuming La Niña does persist through summer, the influence on the monsoon is not well understood, partly due to the inherent variability and volatility of the monsoon, and limited sample size of ENSO events that persist over the summer period. The signal is more clear in winter, and if La Niña conditions stick around that long, the Southwest can anticipate seasonal outlooks that call for below average winter precipitation.
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