MANILA - Tropical cyclone warning signal number 2 remained raised over the province of Batanes on Monday as Typhoon "Helen" slightly intensified, state weather bureau PAGASA said.

The Babuyan group of islands, meanwhile, remained under signal number 1.

PAGASA, in its 6 a.m. advisory, said the typhoon was packing maximum sustained winds of 150 kilometers per hour (kph) near the center and gusts of up to 185 kph.

Moderate to heavy rains were seen within the 800-kilometer diameter of Helen, which was plotted 610 kilometers east of Basco, Batanes at 5 a.m.

If the storm continues moving west northwest at 22 kph, Batanes will experience the height of the typhoon's onslaught on Tuesday between 2 and 3 a.m., PAGASA meteorologist Jori Loiz told said.

"Ang pinakamalapit po ni Helen sa Batanes ay bukas po ng madaling-araw. Mararanasan niya iyung malalakas na hangin at pag-ulan. Pero once na tumama na si Helen sa lupa, maaaring hapon po ito, unti-unti nang hihina si Helen," Loiz told radio DZMM.

[Helen will be come nearest to Batanes tomorrow (Tuesday) morning. Batanes will experience strong winds and rains. But once Helen hits land, possibly in the afternoon, Helen will gradually weaken.]

Batanes is still reeling from effects of recent typhoon 'Ferdie.'

• LOOK: Typhoon Ferdie's trail of destruction in Batanes

In the meantime, Loiz said light to moderate rains with isolated thunderstorms will prevail over the rest of Luzon, Visayas, Caraga, northern Mindanao and Zamboanga peninsula.

Helen is expected to leave the Philippines area of responsibility on Wednesday morning.

The National Disaster Risk Reduction and Management Council has pre-positioned relief supply, rescue equipment and power generator sets in Batanes and other provinces in the typhoon's path, agency spokesperson Mina Marasigan said.