MANILA, Philippines - The low-pressure area (LPA) spotted off Mindanao yesterday might develop into a tropical cyclone this week that could shorten summer and trigger the onset of an early rainy season, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said.
“The LPA may develop into a tropical cyclone later this week. It would affect the Visayas and Southern Luzon from Friday to Saturday,” Pagasa administrator Prisco Nilo told The STAR in a phone interview.
Nilo said the tropical cyclone would be given the local name “Crissing.”
As of 2 p.m. yesterday, the LPA was estimated based on satellite and surface data at 695 kilometers east of Mindanao.
An LPA is commonly associated with bad weather. A tropical cyclone, if on sea, can be formed in such condition.
Nilo said a tropical cyclone is strong enough to enhance the southwest monsoon or hanging habagat which is the prevailing wind system during the rainy season.
“The rainy season may start a week earlier than in previous years,” Nilo said.
The usual onset of the rainy season is during the second or third week of May.
Last year, the weather bureau officially declared the onset of the wet season in the western section of the Philippines on May 15.
Nilo said a 25-millimeter rainfall requirement and a southwest monsoon that should be the prevailing wind system are just some of the criteria used in declaring the onset of the rainy season.
He also said a total of 25 mm of rainfall must be recorded for five consecutive days in five weather stations in the western part of the country to say that the rainy season has indeed come.
Nilo said although the amount of rainfall recorded in the past several days has already exceeded the 25-mm requirement, the southwest monsoon is still not the prevailing wind system in the country.
Earlier, Nilo said the country is experiencing an “abnormal” summer season due to the presence of several rain-producing weather systems such as the low pressure areas, the intertropical convergence zone (ITCZ) and cold front. He attributed this to climate change.
Meanwhile, Nilo said mostly cloudy skies with scattered rain showers and thunderstorms would continue to prevail over Luzon and Mindanao early this week.
The rest of the country would be partly cloudy to cloudy with isolated rain showers or thunderstorms mostly in the afternoon or evening.
He said moderate to occasionally strong winds blowing from the northeast would prevail over extreme northern Luzon and its coastal waters would be moderate to occasionally rough.
Light to moderate winds blowing from the southwest and southeast would prevail over the rest of Luzon and coming from the northeast to northwest over the Visayas and Mindanao with slight to moderate seas.