Metro Manila is likely to experience rainfall in the next three days as Tropical Depression ''Crising'' is expected to develop into a tropical storm and enhance the southwest monsoon.

As ''Crising'' is anticipated to intensify into a tropical storm on Thursday night or Friday morning and reach severe tropical storm by Saturday, the National Disaster Risk Reduction and Management Council (NDRRMC) raised its alert status from blue to red on Thursday noon.

According to the state weather bureau, "a landfall scenario over mainland Cagayan by Friday evening is possible" before Crising "will move westward traversing the northern portion of Northern Luzon, and turn west northwestward until it exits the Philippine Area of Responsibility by Saturday (19 July) afternoon."

In its 5pm advisory, the bureau said Metro Manila and other provinces are expected to experience 50 to 100 mm amount of rainfall which may cause localized flooding in areas that are urbanized, low lying, or near the rivers. Landslides are also highly possible in susceptible areas from Friday up to Sunday.

The southwest monsoon may also bring 100 to 200 mm rainfall in the provinces located in the western part of the country in the next three days.

''Crising'' is expected to bring up to 200 mm rainfall or widespread incidents of severe flooding and landslides in the affected provinces in Northern Luzon.

As of 4 pm on Thursday, the Philippine Coast Guard (PCG) monitored a total of 271 passengers, truck drivers and cargo helpers who were stranded in three different ports in Eastern Visayas because of ''Crising''.

Also stranded in the affected ports includes 135 rolling cargoes, and three vessels while two other vessels taking shelter due to the tropical depression.

The Civil Aviation Authority of the Philippines (CAAP) also reported that a total of eight flights were cancelled while another one was diverted due to unfavorable weather conditions brought by the tropical depression.

It also placed all its 44 CAAP-operated airports under heightened alert as ''Crising'' moves across the Philippine Area of Responsibility (PAR).

CAAP director general Raul del Rosario has instructed all area and airport managers in potentially affected regions to activate their respective Airport Emergency Plans (AEPs) without delay and to maintain close coordination with local Disaster Risk Reduction and Management Councils (DRRMCs), airline operators, and other airport stakeholders to ensure passenger safety, secure facilities, and uphold continuous operational readiness.

"The Bicol region, as the area mostly affected by Tropical Depression 'Crising', is currently making necessary preparations, particularly in the airports of Bicol (Legazpi), Naga, Virac, and Masbate," CAAP said.

As of 5 pm, ''Crising'' was last spotted at 335 km Northeast of Virac, Catanduanes or 545 km east of Baler, Aurora.

Crising with maximum sustained winds of 55 kph near the center and gustiness of up to 70 kph was moving north-northwestward at the speed of 30 kph.

Batanes, Cagayan including Babuyan Islands, Isabela, Quirino, the northern portion of Nueva Vizcaya (Kasibu, Quezon, Bagabag, Diadi, Bayombong, Solano, Ambaguio, Villaverde, Dupax del Norte, Bambang, Kayapa), the northern portion of Aurora (Dilasag, Casiguran, Dinalungan, Dipaculao, Baler), Abra, Apayao, Kalinga, Mountain Province, Ifugao, the northern portion of Benguet (Bakun, Mankayan, Buguias, Kibungan, Kabayan, Bokod, Atok, Kapangan), Ilocos Norte, Ilocos Sur, the northern portion of La Union (Bangar, Sudipen, Luna, Balaoan, Santol, San Gabriel, Bacnotan), Polillo Islands, Camarines Norte, the northern portion of Camarines Sur (Caramoan, Garchitorena, Lagonoy, San Jose, Presentacion, Tinambac, Siruma, Goa), and Catanduanes remain under tropical cyclone wind signal number one as of Thursday night. Robina Asido/DMS