Interactions between Typhoon Nanmadol and Tropical Storm Talas, both east of Taiwan, will determine their potential influence on the country, the Central Weather Bureau (CWB) said yesterday.
The bureau said the 11th and 12th storms of this year’s Pacific typhoon season appear to be converging upon each other during formation, which makes their trajectories uncertain.
They are currently exhibiting the so-called “Fujiwhara effect,” the bureau said, in which two nearby storms tend to orbit each other, spiral into a point between the two systems, and merge eventually.
“The path of a typhoon usually depends on the strength of the sub-tropical high,” forecaster Hsieh Min-ken (謝旻耕) said. “The Fujiwhara effect has made it harder to predict this time.”
As of 8am yesterday, Nanmadol was centered 830km southeast of Oluanpi (鵝鑾鼻), the southernmost point of Taiwan, while Talas was 2,100km east-southeast of Taiwan.
Nanmadol was moving west at 11kph, packing sustained winds of 119kph, Hsieh said, and Talas was moving north-northwest at 9kph, packing sustained winds of 65kph.
The distance between the two storms was 1,600km and continued to shrink, he said.
The bureau said it would have a better idea about the impact of both storms tomorrow, after the two systems have had some time to interact.
Nevertheless, the bureau warned that showers in the north and east of the country are likely starting tomorrow because of the effect of Nanmadol’s outer bands.