Morakot exposed CWB’s forecasting failures: academic

By Jenny W. hsu  /  STAFF REPORTER

Thu, Mar 25, 2010 - Page 2

Seven months after Typhoon Morakot killed 680 people in southern Taiwan, scientists yesterday suggested that global warming might not have caused the deadly rainstorm, but acknowledged that the Central Weather Bureau’s (CWB) forecasting ability has much room for improvement.

Speaking at a press conference at the National Science Council, Hsu Huang-hsiung (??, a professor at National Taiwan University’s department of atmospheric science, said weather research was based on patterns and not on an isolated event such as Morakot.

Scientists cannot rule out the possibility that global warming was the cause of the typhoon, but “the evidence we have so far does not directly indicate global climate change was the main cause,” he said.

The unusual weather patterns brought on by El Nino and the combination of two other typhoons in the Pacific rim — Goni and Etau — attributed to the strong winds and prolonged rainfall lasting a total of 64 hours between Aug. 6 and Aug. 9 last year.

Although the eye of the typhoon was located in the north, the asymmetrical structure of Morakot, which had higher concentrations of cloud and extreme precipitation in its lower region, resulted in torrential rain and strong winds in the southern of the country.

Hsu said Morakot was moving at a speed of 20kph, but the mountainous topography had slowed it to 10kph as it approached Taiwan and it even remained stationary at times, a fact that contributed to the torrential downpours in certain areas.

Morakot was classified as a medium to strong typhoon, equivalent to a category 2 hurricane. It brought a new rainfall record of 2,777mm for Alishan. The previous record of 1,736mm was set by Typhoon Herb in 1996.

Some 145 cities and townships, spanning nine counties, reported flooding. A total of 44 bridges and 138 highways were damaged by mudslides and floodwater. Several Aboriginal villages were destroyed, including Siaolin Village (小林), which was entirely wiped out. The estimated damage to agriculture was NT$11.1 billion (US$337.4 million).

The government was heavily criticized for its slow response to the disaster and several Cabinet members, including the former premier, were forced to step down.

While the scientists agreed that the strength of nature’s power was often unpredictable, Hsu said the CWB’s forecasting was lackluster and suggested the bureau update their satellite imaging equipment, strengthen exchanges with related international agencies, such as NASA, and build more detection centers in mountainous regions.

Cheng Ming-dean (鄭明典), director of the CWB’s Forecast Center acknowledged that the bureau’s computer systems and equipment were not “as advanced when compared with other countries,” but maintained that the nation’s forecasting ability remained “up to scratch.”