Another low-pressure area (LPA) formed east of the country Monday and may enter the Philippine Area of Responsibility (PAR) within 36 hours.
According to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA), the new LPA was estimated at 1,500 kilometers (kms) east of Mindanao as of 10 a.m.
It is less likely to develop into a tropical depression but its trough or extension may contribute rainfall over the country.
Meanwhile, the two LPAs that brought significant rains over a large swath of the country over the weekend was estimated at 115 kms north-northeast of Casiguran, Aurora and at 250 kms west-northwest of Puerto Princesa City Monday morning.
PAGASA said these weather disturbances inside the PAR also remain less likely to develop into a tropical depression in the next 24 hours.
However, the State weather bureau said the combined effects of the trough of the LPA outside PAR and the LPAs within the country may bring moderate to heavy rains over the northern and eastern portions of Cagayan, including Babuyan Islands, eastern portion of Isabela, and Kalayaan Islands Monday.
Light to moderate with at times heavy rains may also affect the rest of Cagayan and Isabela, Batanes, Quirino, Nueva Vizcaya, Apayao, Kalinga, Mountain Province, Ifugao, Aurora, northern portion of Quezon, including Polillo Islands, Palawan, including Calamian, Cuyo, and Cagayancillo Islands, Biliran, Eastern Samar, Leyte, Northern Samar, Samar, Southern Leyte, Agusan del Norte, Agusan del Sur, Surigao del Norte, Surigao del Sur, and Dinagat Islands.
By Tuesday, moderate to heavy rains may still affect the northern and eastern portions of Cagayan, including Babuyan Islands, Batanes, and Kalayaan Islands.
Light to moderate with at times heavy rains may also prevail over the rest of Cagayan, Isabela, Quirino, Nueva Vizcaya, Apayao, Kalinga, Mountain Province, Biliran, Eastern Samar, Leyte, Northern Samar, Samar, Southern Leyte, Agusan del Norte, Agusan del Sur, Surigao del Norte, Surigao del Sur, Dinagat Islands, Davao Oriental, Davao Occidental, Davao de Oro, Davao del Norte, and Davao del Sur.
PAGASA continued to warn against possible flooding, including flash floods, and rain-induced landslides that may occur during heavy or prolonged periods of rainfall, especially in areas that are highly susceptible to these hazards.
Other areas that received significant antecedent rainfall over the past couple of days or weeks were also advised to take precautionary measures in case flooding or landslides occur due to these weather disturbances.
Likewise, adjacent or nearby areas that may not have been directly affected by the rainfall were urged to remain alert due to the possibility of flooding from surface runoff or swelling of river channels.
PAGASA said the rest of the country will have partly cloudy to cloudy skies with isolated rain showers due to localized thunderstorms.
It advised the public to take necessary precautionary measures against possible flash floods or landslides in the event of severe thunderstorm activity.