Northwest Pacific Tropical Cyclone Season Outlook 2020

The period of 2020 to date has seen weak positive El Nino conditions over the central Pacific but below the threshold (+0.8). Most of the models show the current NINO3.4 anomaly decreasing during the next few months, with the dynamical model average becoming negative by July and remaining negative until at least November. However, they remain in the neutral range. Several of the models indicate values falling more rapidly over the coming months with La Nina conditions developing during the northern hemisphere summer (June-July-August) then persisting through the rest of the year.

Based on the above conditions, the expected number of tropical cyclones (TC), tropical storm intensity or greater, over the NW Pacific region in the 2020 season is 25 which is slightly above the long term (1970‐2016) average. The systems that form are expected to be of near average intensity with Accumulated Cyclone Energy (ACE) 109% of the long term average.

About 11 tropical cyclones are expected to affect the South China Sea, which is also slightly above average. The systems that form are expected to be of above average intensity when compared to the long‐term average (ACE is 132% of normal).