The nation enters typhoon season today and the Central Weather Bureau (CWB) says that three to five typhoons or tropical storms are likely to hit this year.
The typhoon season begins in July and ends in September. This year, however, four tropical storms have formed in the northwest Pacific Ocean since May, with Tropical Storm Linfa hitting the outlying islands of Taiwan.
Daniel Wu (吳德榮), director of the CWB’s forecast center, said that about 24 to 27 typhoons could form in the northwest Pacific Ocean this year, but only three to five of them would likely pose a threat to Taiwan.
Data from the past 30 years showed that the average number of typhoons in the northwest Pacific Ocean between July and September is 26.6. And on average, about three typhoons hit Taiwan, the bureau said.
In the past five years, however, the average number of typhoons in the same area during these three months was 24.2, with around four hitting Taiwan.
Wu added that sea temperature of the central Pacific would affect where typhoons or tropical storms form.
“The sea temperature has risen slightly,” he said. “This will potentially cause typhoons or tropical storms to form around Guam. In that case, typhoons are more likely to develop into major typhoons because they tend to stay longer over the sea and can absorb more water vapor.”
“So far, however, we’ve also seen tropical storms form around the South China Sea and the Philippines,” he said.
Wu also said meteorologists from the UK and Hong Kong estimated 27 typhoons would form in the northwest Pacific.
The bureau also presented figures on rainfall during the Plum Rain season, which lasts from May to June.
Accumulated rain in these two months normally accounts for one-third of annual rainfall.
Wu said the data showed that the amount of rainfall in May was less than average, but normal last month.
As of Sunday, the average accumulated rainfall at the bureau’s 13 observation stations nationwide was 279.6mm, or 227mm less than average.
This made this year’s Plum Rain season the fifth driest on record, following dry spells in 1980, 1954, 1971 and 2004.