Study predicts near-normal tropical cyclone activity

The Guy Carpenter Asia-Pacific Climate Impact Centre at the School of Energy and Environment, City University of Hong Kong, has released its 2020 predictions for tropical cyclone formations and landfalls using a regional climate model focusing on East Asia.

This model uses information from a global climate prediction model made available in March 2020. A few highlights from the findings include: 

• The number of tropical cyclone formations predicted for the six month period from April 1 and September 30 is approximately 22.6, which is near the 1977-2018 six-month average of 21.1.
• Of the 22.6 formations predicted, fewer than 9.4 will make landfall, which is similar to the 1977-2019 average of approximately 9.5.

Currently, El Niño–Southern Oscillation (ENSO) neutral conditions are present with near-to-above average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific, along with patterns of anomalous upper-ocean heat and winds consistent with a neutral state.

Since September 2019, the Pacific Ocean has experienced near-to-above-average SSTs, especially in the far western and far eastern Pacific Ocean. The U.S. National Oceanic and Atmospheric Administration (NOAA) predicts that ENSO neutral conditions will continue through the first half of 2020.

Consistent with what is typical in ENSO neutral conditions following a weak El Niño year, the number of tropical cyclones predicted to form between April 1 and September 30 is below- to near-normal.

However, across the regions of East Asia, the number of tropical cyclone landfalls is quite varied with below-normal numbers for the Japan and Korea region, near-normal numbers for the Eastern China and Taiwan region and the South China and Vietnam region and above-normal numbers for the Philippines.

Tropical cyclone activity from 1977 through 2018 is used as the reference period for defining normal activity and is also referred to as climatology.

Based on the six ENSO-neutral years, the average number of tropical cyclone landfalls predicted to make landfall is near-normal for the entire region. For each sub-region, the average number of tropical cyclone landfalls is predicted to be near-normal for Japan and Korea and above-normal for all other regions.

Updated forecasts including October and November will made available in the upcoming months. The regional climate model has also been modified and validated for the Australian region and will be run in SeptemberOctober for the upcoming 2020/2021 Australia cyclone season.