MANILA - The weather disturbance east of Mindanao has developed into tropical depression Ulysses and is threatening the Bicol region, the state weather bureau said.

PAGASA said Ulysses, which developed into a tropical depression at 8 p.m. Sunday, is forecast to intensify into a tropical storm within 24 to 36 hours.

The country's 21st storm this year was last spotted 800 kilometers east of Hinatuan, Surigao as of 10 p.m., packing maximum sustained winds of 45 kilometers per hour near the center, with gusts of up to 55 kph, PAGASA said in its 11 p.m. weather bulletin.

Ulysses is moving northwest at 15 kph and is forecast to move in the same direction until Tuesday morning.

It is then forecast to turn west and head towards the Bicol region where it may make landfall by Wednesday.

Ulysses has no direct effect on the country's weather yet, but it may bring winds and rain in parts of Eastern Visayas and Bicol region by Tuesday or Wednesday.

Meanwhile, tropical depression Tonyo, which is poised to leave the Philippine Area of Responsibility by Monday, was last estimated 395 kilometers west of Calapan City, Oriental Mindoro as of 10 p.m., moving west at 30 km per hour while packing maximum winds of 55 kph near the center and gusts of up to 70 kph.

• Tropical depression Tonyo poised to exit, new LPA may intensify: PAGASA

Tonyo will bring moderate to heavy rains over Kalayaan Islands from Sunday to Monday.

The tail-end of a cold front associated with the northeast monsoon (amihan) enhanced by Tonyo will also bring moderate to heavy rains over mainland Cagayan Valley, Cordillera Administrative Region, and Aurora.

Light to moderate with at times heavy rains, meanwhile, will be experienced over Ilocos Region, the rest of Central Luzon, Batanes and Babuyan Islands.