As it draws more strength from the warm ocean waters, tropical cyclone "Ulysses" (international name: "Vamco") was upgraded into a tropical storm by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) on Monday afternoon.

Ulysses was packing 65 kilometers per hour (kph) near the center and gustiness of up to 80 kph, PAGASA said in its severe weather bulletin issued at 5 p.m.

From a tropical depression on Monday morning, Ulysses intensified into a tropical storm around 2 p.m.

While still over the sea, PAGASA said Ulysses may reach the severe tropical storm status within 24 hours and further into a typhoon by Wednesday.

The center of the storm was estimated at 575 kilometers (km) east of Borongan City, Eastern Samar, moving northwest at 15 kilometers per hour (kph), as of 4 p.m.

It may continue to move generally northwest through Tuesday afternoon before turning west towards the Bicol region-Quezon area. 

As Ulysses slightly slowed down, a landfall over Bicol region-Quezon area on Thursday is likely at this time, PAGASA said.

According to weather specialist Chris Perez, the center track of the tropical cyclone's area of probability points to Catanduanes as of the moment.

But since Ulysses is still a bit far, there could still be some changes in its final track.

Its center track could still move more to the southern part of Bicol region or Northern Samar, or more to the north of its possible landfall, Perez said.

However, as early as now, he advised the public, particularly those in Metro Manila, Bicol region, Southern Luzon, and Central Luzon to prepare for the possible direct effect of this weather disturbance in the coming days.

Light to moderate with at times heavy rains may prevail over Eastern Visayas, Bicol region, and Quezon province starting on Monday evening due to trough or extension of Ulysses.

Meanwhile, moderate to heavy rains may affect Cagayan including Babuyan Islands, Apayao, and Ilocos Norte due to the tail-end of cold front.

PAGASA warned that flooding, rain-induced landslides, and sediment-laden streamflows or lahar may occur during heavy or prolonged rainfall especially in areas that are highly susceptible to these hazards. 

Based on available data, Perez said tropical cyclone wind signal number 1 may be raised over some areas in Bicol region and Eastern Visayas as early as Monday evening or Tuesday morning in anticipation of the onset of strong breeze to near gale conditions associated with Ulysses.

A gale warning is currently in effect due to rough to very rough sea conditions over the seaboards of Northern Luzon, eastern seaboard of Central Luzon, eastern and western seaboards of Southern Luzon, and eastern seaboard of Visayas.

Sea travel has been suspended in these areas.

If Ulysses remains on course, it will be around 555 km east of Daet, Camarines Norte by Tuesday afternoon; 320 km east of Infanta, Quezon by Wednesday afternoon; 130 km west of Pasay City, Metro Manila by Thursday afternoon; and at 660 km west of Pasay City or outside the Philippine area of responsibility by Friday afternoon.