Philippines: Adverse weather forecast across southern and central regions through at least April 29 /update 1

Event

Heavy rainfall and thunderstorms are forecast across southern and central parts of the Philippines through at least April 29. Heavy downpours and overflowing rivers could trigger flooding and landslides. As of April 28, the Philippine Atmospheric, Geophysical, and Astronomical Administration (PAGASA) has warned of a low-pressure area bringing moderate to heavy rain with at times intense rains over Caraga and Palawan provinces and the Zamboanga Peninsula Region over the next 24 hours. Light to moderate rain with at times heavy rainfall is expected over the rest of the Visayas and Mindanao regions.

PAGASA has issued the following flood advisories across the affected area:

• Severe general flood advisory (the second-lowest level on a four-tier scale): Zamboanga Del Norte, Zamboanga Del Sur, and Zamboanga Subigay provinces in Zamboanga Peninusla Region.

• Moderate general flood advisory: Basilan, Lanao Del Sur, Maguindanao, and Sulu provinces in the Bangsamoro Autonomous Region in Muslim Mindanao; Palawan Province in Mimaropa Region; Bukidnon, Camiguin, Lanao Del Norte, Misamis Occidental, and Misamis Oriental provinces in Northern Mindanao Region; North Cotabato, Sarangani, South Cotabato, and Sultan Kudarat provinces in Soccsksargen Region; and Aklan, Antique, and Negros Occidental provinces in Western Visayas Region.

Officials could update and possibly extend the coverage of weather alerts over the coming days.

Heavy rainfall caused flooding in Cotabato, Maguindanao, and Sultan Kudarat provinces on Mindanao island April 27. Over 1,000 families were displaced by flooding in Barangay Saniag of Ampatuan town in Maguindanao Province due to flash floods. The national highway in Barangay Paril of Kalamansig town in Sultan Kudarat Province was inundated by floodwaters. Other instances of flash flooding have been reported across parts of the affected provinces. Further heavy rainfall over the coming days will likely exacerbate the situation in areas where the ground is already saturated and hamper ongoing response and recovery efforts.

Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Philippine Atmospheric, Geophysical, and Astronomical Adminstration (PAGASA)