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The 2016 typhoon season in review

The typhoon Season of 2016 is unique, and although it started late, the observation shows that the overall TC activity fell within our expectation. A total of 26 named events were recorded over the north western Pacific basin with the intensity of tropical storm or higher. This made 2016 very close to the historical (1981 – 2010) average of 25.5. During the entire season, nine events made landfall in China (eight in South China and one in Northeast China), eight made landfall in Japan, three recorded in Vietnam and one in South Korea.

Although the overall activity including the formation, duration and travel pattern throughout the 2016 tropical season was within expectation, the first event was only recorded in early July (Fig 1). We predicted a delay and sizable season for 2016 in our October update. In that report, we highlighted two main travel patterns of which one was going north-westerly, the other travelling a northly route. Therefore, most events headed towards China and Japan.

Fig 1 Tropical cyclone activity summary of 2016 (Only the events with intensity higher than or equal to tropical storm are considered in this report)
Fig 2. No. 2 Lupit, No. 10 Lionrock, and No.11 Kompasu

Out of all events, No. 10 Lionrock ( 獅子山 ) had the longest lifetime of 12 days. It first travelled southwest then turned 180 degrees to the northeast at around 600km east to Taiwan and made its first landfall in northern Japan and then again in Russia. Eventually it entered and dissipated in China’s north-eastern Jilin province. In contrast, No. 2, LUPIT ( 卢碧 ) and No. 11, KOMPASU ( 圓規 ) had the shortest lifetime of two days. They formed, reached the highest intensity of tropical storm and vanished quickly over the ocean in 48 hours.

Fig 3 Typhoon Meranti (source: Peak Re TCAT)

The strongest event however was No.14, Meranti ( 莫 兰 蒂 ). On 13 September 2016, it recorded the highest wind speeds of over 70 m/s (similar to 252 km/h) before it entered Bashi Channel (point A, Fig 3). As it didn’t make landfall in Taiwan (point B Fig 3), its eye structured was not damaged and hence its intensity remained strong until it landed in Xiamen, China (point C Fig 3) as a severe typhoon (or CAT 4 event in Saffir-Simpson scale). Meranti was the only event which impacted eastern China more than all others in 2016.

Fig 4 2016 Typhoon Corridor (source: Peak Re TCAT)

As a result of the historically strong El Niño event year in 2015, the sea surface temperature (SST) remained at a positive anomaly over the central tropical Pacific Ocean. This changed the formation pattern of the tropical cyclones. Specifically, during the 2016 season, only five events made landfall in the Philippines which is lower than the historical annual average of 8-9 (source: PAGASA). 10 events, i.e. 38% of the season’s total, were formed and travelled through a 1000km wide area, the so-called “2016 Typhoon Corridor” (Fig 4). As there was not any event formation in the first half of 2016 and with the existence of a strong subtropical high system in the north, the 2016 Typhoon Corridor was seen as obvious and busy during September to October in 2016 and most of the events travel through this corridor made landfall or impacted China significantly.

Fig 5 Origin in 2016 (dots) and frequency distribution of events’ origin (1951-2015) (source: STI)

Another key feature of 2016 season is that the observed TC events were formed (black dots in Fig 5) mostly away from their normal genesis areas (the solid line boxes). The movement from solid line boxes to dash line boxes illustrated the distance of TC genesis shifting by the climate anomaly. As a result, the TC landfall and routing patterns were geared towards China and Japan, without passing the Philippines as seen in previous years.

Fig 6 shows the comparison between historical average and 1973, 1983, 1999 and 2016 – the years following an El Nino year. The significant variations in TC activities observed in those four years and the unique features recorded in 2016 will help us further improve our future seasonal forecasting especially for those anomaly years.

Fig 6 Long term statistics of tropical cyclone formation (1949-2019)

Peak Re will continue to work closely with the Shanghai Typhoon Institute to research tropical cyclone activity in order to provide the market with more solid and efficient risk management solutions.


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