The rainy season has officially started, according to the Philippine Atmospheric Geophysical and Astronomical Services Administration (Pagasa) said.

“The observed weather patterns during the past few days signal the onset of the southwest monsoon season,” Pagasa said in a statement. “With these developments, the onset of the rainy season in the country has been established.”

To mark the change of season, the country’s first storm for the year has been spotted in Visayas.

In its 5 a.m. bulletin. “Ambo” was estimated 260 kilometers northeast of Borongan in Eastern Samar with maximum sustained winds of 55kph near the center and moving northwest at 17kph.

Due to Ambo, Catanduanes will have rains with gusty winds with moderate to rough seas. The rest of the country will have mostly cloudy skies with scattered rainshowers and thunderstorms over the rest of the eastern section of southern Luzon and Visayas that could trigger flashfloods and landslides.

Signal no. 1 has been declared in Catanduanes and Samar. The two provinces should expect heavy rainfall measuring from 10-15mm/hr within 400 kilometers of Ambo.

Ambo is expected to be at 330 kilometers North Northeast of Virac, Catanduanes or 320 km East of Casiguran, Aurora by tomorrow morning.

It will be at 390 kilometers East Northeast of Aparri, Cagayan by Sunday morning. By Monday morning, it will be at 530 kilometers Northeast of Basco, Batanes.