Metro Manila (CNN Philippines, September 15) — "Nanmadol" has intensified into a severe tropical storm and is expected to become a typhoon when it enters Philippine territory within 24 hours, the state weather bureau said Thursday.

In its 11 a.m. weather advisory, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said Nanmadol was spotted 1,760 kilometers east northeast of extreme northern Luzon.

It slightly intensified as it moved west northwestward, with winds of 95 kilometers per hour and gusts of 135 kph, it also said.

It may enter the country as a typhoon on Thursday evening or early Friday morning and will be given the domestic name Josie, the 10th tropical cyclone for the year and the second for September, PAGASA added.

"Magiging mabilis ang paglakas nito. Maaring ngayong araw ay lumakas pa ito...at pagpasok ng PAR (Philippine Area of Responsibility) ay maging isang typhoon," PAGASA weather forecaster Benison Estareja said.

[Translation: Nanmadol will intensify rapidly. It may be even stronger today and enter PAR as a typhoon.]

It is moving west northwestward at 15 kph and may bring strong to storm-force winds that could extend outwards up to 460 km from its center, according to Estareja.

Nanmadol is forecast to remain far from the Philippine landmass, but it may enhance the southwest monsoon which will bring rains over the western sections of Southern Luzon, the Visayas, and Mindanao within the day.

In the next 24 hours, the southwest monsoon will bring moderate to heavy with at times intense rains over Antique, Aklan, Negros Occidental, Occidental Mindoro, and Palawan.

Meanwhile, light to moderate with at times heavy rains will prevail over Oriental Mindoro, the rest of Western Visayas, the Zamboanga Peninsula, and the Bangsamoro Autonomous Region in Muslim Mindanao, according to PAGASA.

Under these conditions, scattered flooding and rain-induced landslides are likely, especially in areas that are highly or very highly susceptible to these hazards as identified in hazard maps and in areas with significant antecedent rainfall, the bureau said.

Once inside the country, Nanmadol may only linger in the northern part of the Philippine Sea in less than 24 hours. Upon its exit, it will head towards the southern portion of Japan and the East China Sea.