Pagasa said a low-pressure area inside the Philippine area of responsibility may develop into a tropical cyclone by Wednesday.
The weather bureau said the LPA currently had a medium chance of intensifying into a cyclone.
As of the latest monitoring, the weather disturbance was located 495 kilometers east of Surigao City in Surigao del Norte.
Pagasa said the LPA is expected to move across the Southern Luzon-Visayas area on Tuesday before reaching the West Philippine Sea by Wednesday.
Weather specialist Aldczar Aurelio said the likelihood of the LPA becoming a tropical cyclone would increase once it reaches the West Philippine Sea.
If the weather disturbance intensifies into a cyclone, it will be named Henry and will become the country’s eighth tropical cyclone for 2026.
Pagasa said the LPA is expected to bring moderate to heavy rains over Sorsogon, Masbate, Northern Samar, Eastern Samar, Samar, Biliran, Leyte, Southern Leyte, Dinagat Islands, and Surigao del Norte.
The southwest monsoon, or Habagat, continued to weaken and move away from most parts of the country, although Pagasa said it was still affecting western Southern Luzon and may affect Mindanao on Tuesday due to the LPA. No gale warning was raised over any seaboard.