Tropical Depression “Wilma” made landfall in Surigao del Sur province Monday morning, bringing stormy weather in 16 areas in the Visayas, including earthquake-ravaged Cebu and Bohol, and Mindanao.
Wilma, however, weakened into a low pressure area after hitting land, allowing forecasters to concentrate their attention on another weather disturbance approaching the Philippines.
The Hawaii-based Joint Typhoon Warning Center (JTWC) of the US Navy has named that weather disturbance Tropical Storm “Haiyan” from being mere “Tropical Depression 31W.”
Moving west at 20 kilometers per hour, with sustained winds of 65 kph and gusts of up to 83 kph, Haiyan is expected to enter the Philippine area of responsibility (PAR) between Wednesday night and Thursday morning.
When Haiyan enters the PAR, it will be renamed Tropical Cyclone “Yolanda,” the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said Monday.
The JWTC expects Haiyan to gain strength Tuesday morning, with maximum sustained winds of 83 kph and gusts of up to 102 kph.
But Pagasa forecaster Fernando Cada said on Monday that it was too early to tell if Yolanda would become a supertyphoon by JWTC standards, as the cyclone was still too far, about 2,000 km east of Mindanao, or 1,600 km east of the PAR.
By JWTC standards, a weather disturbance should have winds of up to at least 240 kph to be classified supertyphoon.
“Although there are weather models, there is still a 50-50 chance of that happening. It is still within what we call the ‘cone of uncertainty,’ which means there is a large chance of error,” Cada said.
As the cyclone is still too far, certain factors could affect its strength, speed and direction, Cada said.
“It is expected to intensify into a typhoon while still over the ocean, but it can change direction. Like now, it is moving west but later on it could move north-northwest,” he said.
“We can only make a fairly accurate track of the tropical cyclone once it is within the PAR but not when it is still too far,” he said, referring to reports on the Internet saying “Supertyphoon Yolanda” making landfall in Leyte province by Friday.
Pagasa does not use the category “supertyphoon,” Cada said.
“Although it is too soon to forecast [the cyclone’s] track, what we can advise the public is to always be prepared,” he said.
Wilma hit land in Tandag town before noon Monday with maximum winds of 55 kph.
By afternoon, however, the storm had weakened into a low pressure area that was embedded in the intertropical convergence zone 15 km southwest of Tagbilaran City.
Earlier, as Wilma approached land, Pagasa raised Storm Signal No. 1 over Camiguin, Dinagat and Siargao islands; Surigao del Norte; Surigao del Sur; Agusan del Norte; Agusan del Sur; Misamis Oriental; Misamis Occidental; and the northern part of Zamboanga del Norte.
Signal No. 1 was also raised over the southern parts of Negros Occidental and Negros Oriental; southern Cebu; Siquijor; Bohol; and Southern Leyte in the Visayas.
Pagasa lifted the storm signal after Wilma turned into a low pressure area.
The weather bureau, however, alerted the Visayas as well as the Zamboanga Peninsula, Northern Mindanao and Caraga regions for possible flash floods and landslides that may be triggered by moderate to occasionally heavy rain and thunderstorms on Tuesday.
In earthquake-ravaged Bohol, nearly 2,000 travelers were stranded at Tubigon port after the Philippine Coast Guard grounded all vessels in expectation of Wilma’s arrival.
Many of those stranded were going back to work and school after the All Saints’ Day and All Souls’ Day commemorations during the weekend.
The suspension of sailings was announced at noon, and many of the travelers decided to go home.
Others, however, chose to stay and wait for the resumption of trips.
Cada told the Inquirer that from 1948 to 2010, tropical cyclones that entered the Philippines during October, November and December had a high percentage of making landfall.
He explained that it was because around October through December the concentration of the intertropical convergence zone, which he described as a breeding ground for low pressure areas, was usually over the south of the country, particularly over the Visayas and Mindanao.
Pagasa expects three to five more tropical cyclones to hit the Philippines before the year ends, Cada said.—With a report from Jhunnex Napallacan, Inquirer Visayas