2019 tropical cyclone activity updates

Peak Re partners with the Shanghai Typhoon Institute (STI)
to release the seasonal forecast of tropical cyclone activities
over the Northwest Pacific Ocean (NWPO) and the South
China Sea (SCS) for 2019.

2019 August cyclone activity forecast

El Nino conditions have existed in the Eastern Pacific Ocean since the winter of 2019 and are forecast to persist for a minimum of three further months.

Based on current climate status and activity in 2019 to date, an annual total of 23-25 Tropical Storms are forecast to form over the North West Pacific and South China Sea in 2019 which is below the Long Term Climate Average (LTCA). Seven to eight tropical storms (TS) are forecast to make landfall in China, which is in line with the Long Term Climate Average.

An annual total of 12–13 tropical cyclones (TC) are forecast to impact China in 2019, which is below the Long Term Climate Average. Eight to nine Tropical Cyclones are forecast to impact South and East China respectively which is within with the Long Term Climate Average.

Table 1: Forecast of Tropical Cyclone Activity

Prediction factors

As of the eighth of August 2019, ten Tropical Cyclones have formed over the North West Pacific and South China Sea of which four made landfall in Japan, three made landfall in China, two made landfall in South Korea and one made landfall in Thailand.

El Nino conditions have existed in the Eastern Pacific Ocean since the winter of 2019 and are forecast to persist for a minimum of three further months.

There are three possible development directions from the current El Niño status:

Figure 1: TC activity over the NWPO and the SCS, as at 18 August 2019
  • EN–EN, which means maintaining El Niño status;
  • EN–LN, which means changing from El Niño to La Niña; and
  • EN–NE, which means changing from El Niño to neutral.

The historical record shows no discernable difference between these different sub-categories of El Nino conditions on the likelihood of formation of Tropical Storms. In all three scenarios, El Nino conditions have coincided with average or below average levels of Tropical Storm formation over the North West Pacific and South China Sea in every instance excepting 1951, 1970 and 2015.

A clustering analysis of the pre-Tropical Cyclone seasonal seas surface temperatures (SST) indicates that 2019 conditions are most similar to those of 1983 and 1987. The Tropical Cyclone activity of those two years are summarized below:

Table 2: TC activities in 1983 and 1987

The 2019 Seasonal Tropical Cyclone Activity Forecast report
and previous issues are available on Peak Re’s website:
https://www.peak-re.com/our-publications/sti-report