A low-pressure area outside the Philippine Area of Responsibility (PAR) has developed into a tropical depression, according to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) in its 5 p.m. bulletin on Sunday.

The center of the tropical depression was last estimated at 1,315 kilometers east of Eastern Visayas as of 4 p.m. Once it enters PAR, likely by Monday, it will be named “Marce.”

The tropical depression is expected to move northwestward quickly until Tuesday, after which it will slow down and shift to a northward direction. By mid-week, it could move northward, then westward, over the waters east of extreme Northern Luzon.

PAGASA cautioned that this part of the forecast remains uncertain, with two possible scenarios: either the tropical cyclone heads toward extreme Northern Luzon or mainland Luzon, or it moves erratically over the Philippine Sea.

The system’s trough is likely to bring rains to extreme Northern Luzon and eastern Luzon starting Monday or Tuesday. If the forecast shifts toward a landfall scenario, heavy rainfall could affect Northern Luzon by Thursday or Friday.

The Philippines has endured several storms in October, including Super Typhoon Julian, Severe Tropical Storm Kristine, and Super Typhoon Leon.