MANILA (2nd UPDATE) -- Tropical storm Hanna will intensify into a typhoon as it nears Batanes province, where a series of earthquakes last week flattened housesand left at least 9 dead, the state weather bureau said Monday.

At 3 p.m., Hanna was 845 kilometers east of Aparri, Cagayan. It maintained its strength, with maximum sustained winds of 85 kilometers per hour and 105 kph gusts, said PAGASA.

It is moving west northwest at 10 kph.

The weather disturbance is expected to strengthen into a severe tropical storm by Tuesday afternoon, and into a typhoon by Wednesday, PAGASA weather specialist Aldczar Aurelio said.

Hanna is unlikely to hit land. It is expected to leave the Philippine area of responsibility by Friday.

From Monday to Tuesday, Hanna will enhance the habagat or southwest monsoon, which will bring moderate to at times heavy rains over the northern portion of Palawan, including Calamian and Cuyo Islands, Mindoro provinces, Romblon, and Western Visayas.

Metro Manila, Central Luzon, Calabarzon, Bicol Region, and the rest of MIMAROPA and the Visayas will experience scattered rains and thunderstorms, said the weather agency.

Floods and landslides may hit these areas during severe thunderstorms, PAGASA said.

Bad weather has grounded several flights and forced the cancellation of classes in some parts of Metro Manila and nearby provinces.

Visit the ABS-CBN Weather Center for the latest weather updates.