The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) on Sunday evening, July 18, said tropical storm "Fabian" (international name "In-fa") will remain far from the country's landmass but will continue to stir up the southwest monsoon or "habagat."
As of 10 p.m., Sunday, the center of tropical storm Fabian was estimated at 1,085 kilometers east-northeast of extreme northern Luzon.
It has maintained its maximum sustained winds of 75 kilometers per hour (kph) near the center and gustiness of up to 90 kph while moving north-northwest at 10 kph.
PAGASA said Fabian may become a severe tropical storm by Monday afternoon, July 19, and into a typhoon by Tuesday afternoon, July 20.
It pointed out that Fabian and a tropical depression outside the Philippine area of responsibility (PAR) will enhance the habagat and induce monsoon rains over Ilocos Norte, Ilocos Sur, La Union, Pangasinan, Zambales, Bataan, Occidental Mindoro, and Palawan within 24 hours.
The tropical depression was estimated at 830 km west of extreme northern Luzon on Sunday evening.
Metro Manila and the rest of Luzon, Central and Western Visayas, Northern Mindanao, Zamboanga Peninsula, Tawi-Tawi, Sulu, and Basilan may also experience scattered light to at times moderate to heavy rains and thunderstorms due to the southwest monsoon.
The rest of Visayas and Mindanao will have partly cloudy to cloudy conditions with rain showers or thunderstorms.
PAGASA warned against possible flash floods or rain-induced landslides during heavy or prolonged rainfall, particularly in areas that are highly susceptible to these hazards.
Residents and disaster managers in Batanes and Babuyan Islands were also advised to continuously monitor PAGASA's tropical cyclone bulletins as any further southward shift in Fabian's track may result in the hoisting of tropical cyclone wind signal number 1 over these areas.
"The tropical cyclone will maintain a north-northwestward or northwestward heading at a consistent speed until Monday evening. On the forecast track, the tropical cyclone will exit the Philippine area of responsibility on Tuesday afternoon or evening," PAGASA said.
However, it noted that a southward shift in the orientation of the track forecasts has been observed in the past 24 hours.
"If the trend continues, there is an increasing possibility that Fabian will re-enter the PAR beyond Tuesday or not exit the PAR at all during the forecast period," PAGASA pointed out.