Typhoon "Fabian" (international name "In-fa") accelerated while outside the Philippine area of responsibility (PAR), the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said in its 5 a.m. bulletin on Saturday, July 24.

PAGASA said Fabian left the PAR at around 11 p.m., Friday, July 23.

As of 4 a.m., the center of the eye of typhoon Fabian was estimated at 640 kilometers north-northeast of Itbayat, Batanes.

It has maintained its maximum sustained winds of 140 kilometers per hour (kph) near the center and gustiness of up to 170 kph while moving north at 15 kph.

PAGASA has already lifted the tropical cyclone warning signal number 1 hoisted over Batanes but Fabian is still expected to strengthen the effect of the southwest monsoon or "habagat."

Scattered to widespread moderate to at times heavy monsoon rains may prevail over Metro Manila, Ilocos Norte, Ilocos Sur, La Union, Pangasinan, Abra, Apayao, Benguet, Ifugao, Kalinga, Mountain Province, most of Central Luzon, Cavite, Laguna, Batangas, Rizal, Quezon, Oriental Mindoro, Occidental Mindoro, Marinduque, Romblon, Palawan, and portions of Western Visayas.

The rest of Luzon may also experience scattered moderate to at times heavy rains while the rest of the country will likely have isolated 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.

Occasional gusty conditions associated with the enhanced southwest monsoon will also prevail over Luzon and Visayas, especially in the coastal and upland areas.

PAGASA said Fabian may gradually weaken by Sunday, July 25, while moving towards China.

"However, there is an increasing possibility that this typhoon will further weaken as early as today (July 24). Nevertheless, Fabian is forecast to rapidly weaken as it moves inland after making landfall over eastern China, eventually leading to its degeneration into a remnant low by Tuesday evening (July 27)," PAGASA added.

PAGASA is also monitoring a tropical storm with an international name "Nepartak." It is currently outside the PAR.

It was estimated at 2,855 kilometers east-northeast of extreme northern Luzon as of Saturday morning.

Nepartak has maximum sustained winds of 65 kph near the center and gustiness of up to 90 kph while moving north-northeast at 15 kph.