“Contrary to some belief, PAGASA does not recognize nor use both ‘typhoon signal number 5’ and ‘super typhoon’ categories. But Yolanda [Haiyan] has redefined boundaries.”
By RAYMUND VILLANUEVA
Local meteorologists are seriously considering adding a new storm warning level in anticipation of more extreme weather systems comparable to Typhoon Yolanda (Haiyan).
The Philippine Atmospheric, Geophysical and Atmospheric Administration (PAGASA) said they are close to adding a “signal number 5” next year to tropical cyclone signals 1 to 4 currently in use.
“PAGASA is still discussing the boundaries of new weather models, but we may have announcements along these lines in 2015,” PAGASA Weather Division officer in charge Esperanza Cayanan said at the pilot Seminar on Typhoon and Storm Surge it co-organized with the Japan International Cooperation Agency (JICA) last November 27.
Cayanan also revealed that the agency is considering adopting the “super typhoon” moniker adopted by journalists to refer to typhoons that pack 220 kilometers-per-hour (kph) winds or stronger.
“Contrary to some belief, PAGASA does not recognize nor use both ‘typhoon signal number 5’ and ‘super typhoon’ categories. But Yolanda has redefined boundaries,” Cayanan said.
Yolanda was recorded by the China Meteorological Administration to have two-minute sustained winds of up to 280 kph.
The expert said tropical cyclones that have sustained winds up to 61 kph and weather systems with sustained winds up to 117 kph would remain to be classified as tropical depressions and tropical storms, respectively.
Tropical cyclones currently classified as ‘typhoon’(with sustained winds from 118 kph and stronger) will be limited to just 220kph once ‘super typhoon’ is recognized and issued by PAGASA.
Meteorological agencies in the Western Hemisphere classify hurricanes up to Category 5. Tropical cyclones are called ‘typhoons’ in the West Pacific region while these are called ‘hurricanes’ in the Atlantic and East Pacific regions.
Cayanan admitted PAGASA’s prediction that Yolanda would cross north of Tacloban City was wrong. The typhoon in fact crossed south of what was described as ground zero of the strongest typhoon in recent history.
She also revealed that estimates given by PAGASA were lower than the storm surges that struck the entire Visayas region and the northern Palawan islands.
Storm surges accounted for majority of the casualties from Typhoon Yolanda. The official government count is around 6,300 casualties.
“No weather models are exact, but we maintain that PAGASA did well—all factors considering,” Cayanan said.
Cayanan revealed in her speech that PAGASA has 1,000 times less resources than the Japan Meteorological Agency (JMA) despite the fact that the Philippines has 20 or so tropical cyclones per year while Japan has an annual average of eight a year.
She also denied that the agency did not issue storm surge warnings before Yolanda hit land.
“PAGASA issued warnings that were even highlighted. It was just that they were at the bottom of the bulletins,” she said.
Seminar lecturer and Japanese meteorologist Yasutaka Makihara said that “errors in weather observation and forecasting models may lead to lower storm surge estimates.”
The veteran weather expert said that Japan learned from its “Typhoon Ise-Bay” experience in 1959 when more than five thousand were killed. He said it was the closest comparison they could give to the Philippines’ Yolanda.
He said Japan had since invested heavily on equipment, infrastructure, capability and weather information upgrades that resulted in fewer fatalities from dangerous tropical cyclones.
Makihara drew some laughs when he recommended that the people “should be frightened to some degree” in storm warnings especially when strong typhoons or heavy rainfall in coastal and landslide-prone areas are about to hit.
Cayanan readily agreed with Makihara’s recommendation, however, adding that local government officials should be firm when issuing evacuation orders before extreme weather disturbances.
The seminar became a venue for the announcement of the JICA and PAGASA partnership program in weather observation, forecasting and warning called J-POW (Japan-PAGASA on Weather).
PAGASA said they are now adopting JMA typhoon, storm surge and landslide models that would increase their forecasting capabilities to up to 11 days.