It has been spotted 385 kilometers west-southwest of Basco, Batanes as of 4:00 AM Sunday. Haitang is expected to enter PAR anytime on Sunday and leave by Monday.
Storm signal number 1 is now up over the Batanes group of islands because of Haitang.
Gorio and Haitang, despite being outside PAR, are expected to bring rainy weather to parts of the country as they continue to enhance the southwest monsoon or habagat.
PAGASA said rains with gusty winds will prevail over Batanes, while monsoon rains, which may trigger flashfloods and landslides, are expected over the regions of Ilocos, Cordillera and the provinces of Zambales and Bataan.
Central Luzon and rest of Cagayan Valley meanwhile will have cloudy skies with light to moderate rains and thunderstorms.
Metro Manila will have partly cloudy to cloudy skies with isolated rainshowers or thunderstorms.
The rest of Luzon and the western Visayas will also experience cloudy weather with moderate to strong winds.
Mindanao will have partly cloudy to cloudy skies with isolated rainshowers or thunderstorms with slight to moderate seas.
Typhoon Gorio, whose international name is Nesat, slammed Taiwan on Saturday causing floods and widespread power outages.
Much of Taiwan came to a standstill, with most train services suspended and as many as 249,230 households without electricity as Typhoon Nesat -- packing gust of up to 180 kilometers an hour -- blasted across the country.
More than 10,000 people had to be evacuated, with 4,564 soldiers deployed for disaster relief. -- with a report from AFP