South Pacific tropical cyclone season outlook

The tropical cyclone season runs from 1 November to 30 April

Near average number of tropical cyclones likely in the western Pacific Ocean

  • La Niña in the tropical Pacific Ocean has influenced this year’s tropical cyclone outlook.
  • All surveyed climate models indicate that the La Niña is likely to persist into early 2021
  • Above-average number of tropical cyclones are expected in the western South Pacific region this season (based on 60% probability), with a high level of accuracy.
  • Near-average cyclone numbers are also likely for the eastern South Pacific but model accuracy is very low.

The South Pacific tropical cyclone season is typically from 1 November to 30 April. The average numbers of tropical cyclones during the season in the western and eastern regions are six and four, respectively. Tropical cyclones affect Pacific island countries in most years and can impact coastal regions even when they remain well offshore.

This outlook is based upon the status of the El Niño–Southern Oscillation (ENSO) during July to September 2020. A La Niña event is currently underway in the tropical Pacific. Eastern tropical Pacific Ocean sea surface temperatures have been below average since May and remain below average. Atmospheric indicators of ENSO are also indicative of La Niña. All surveyed climate models suggest ocean temperatures will remain at La Niña levels until early 2021.

Ocean temperatures are currently near to above average across the southwestern Pacific Ocean. Climate models predict waters across this region will remain warmer than average in the coming three months, marginally increasing the likelihood of tropical cyclones developing.

Product code: IDCKSPTCSO