Tropical cyclone "Fabian" (international name "In-fa") has intensified into a severe tropical storm on Monday, July 19, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said in its 11 a.m. bulletin.

Fabian was packing maximum sustained winds of 95 kilometers per hour (kph) near the center and gustiness of up to 115 kph while moving northwest at 15 kph.

PAGASA said that the cyclone may reach the typhoon category by Tuesday evening, July 20. A tropical cyclone is classified as a typhoon once it reaches maximum wind speed of 118 to 220 kph.

As of 10 a.m., July 19, the center of Fabian was estimated at 1,055 kilometers (km) east-northeast of extreme northern Luzon.

PAGASA also continues to monitor a tropical storm with the international name "Cempaka." It is outside the Philippine area of responsibility or at 840 km west-northwest of extreme northern Luzon.

Although the weather disturbances remain far from the Philippine landmass, PAGASA warned against the impact of the southwest monsoon or "habagat" that is being enhanced by Fabian and Cempaka.

"Monsoon rains will be experienced in the next 24 hours over Ilocos Region, Zambales, Bataan, Occidental Mindoro, and Palawan," PAGASA said.

Metro Manila, Cavite, Laguna, Batangas, Rizal, Quezon, Aklan, Antique, Capiz, Guimaras, Iloilo, and Negros Occidental may also have scattered rains showers and thunderstorms.

Meanwhile, Mindanao and the rest of Visayas will have partly cloudy to cloudy skies with 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.

Residents and disaster managers in Batanes and Babuyan Islands were also advised to continuously monitor PAGASA's tropical cyclone bulletins as any further southward shift in Fabian's track may result in the hoisting of tropical cyclone wind signal number 1 over these areas.

"Fabian is forecast to move generally west-northwestward today until tomorrow evening. The tropical cyclone may exit the Philippine area of responsibility tomorrow evening or on Wednesday early morning," PAGASA said.

However, it noted that a southward shift in the orientation of the track forecasts has been observed in the past 24 hours.

"If the trend continues, there is an increasing possibility that Fabian will either re-enter the PAR or exit the PAR much later than the current forecast suggests," PAGASA pointed out.