Philippines: Adverse weather forecast across western regions through at least July 1

Event

Heavy rainfall and thunderstorms are forecast across western parts of the Philippines through at least July 1. The severe weather is associated with a combination of the Southwest Monsoon and the presence of Tropical Depression Caloy located to the west of the Philippines. As of 17:00 PHST June 29, the storm system was located approximately 410 km (256 miles) west of Iba, Zambales Province, and is forecast to track generally northwestward away from the Philippines in the coming days. However, the combination of weather systems will bring heavy rainfall to Palawan, Oriental Mindoro, Occidental Mindoro, Zambales, Bataan, Cavite, Batangas, and Laguna provinces June 29-30. Moderate rainfall is expected during this period over Metro Manila; the rest of Mimaropa region; Ilocos, Bicol, and Western Visayas regions; and Rizal, Tarlac, Pampanga, Aurora, and Quezon provinces. Heavy downpours and overflowing rivers could trigger flooding and landslides. Strong winds are possible in far northern Luzon and western portions of Luzon and Visayas, especially in coastal and mountainous areas. Rough seas are also expected over the seabords of northern, western, and southern Luzon.

As of June 29, the Philippine Atmospheric, Geophysical, and Astronomical Administration (PAGASA) have issued the following flood advisories across the affected area:

• Severe flood advisory (the second-lowest level on a four-tier scale): Aurora, Bataan, and Zambales provinces in Central Luzon region; and Marinduque, Occidental Mindoro, Oriental Mindoro, Palawan, and Romblon provinces in Mimaropa Region.

• Moderate flood advisory: Batangas, Cavite, Laguna, Quezon, and Rizal provinces in Calabarzon Region; Ilocos Norte, Ilocos Sur, La Union, and Pangasinan provinces in Ilocos Region; Aklan, Antique, Capiz, Guimaras, Iloilo, and Negros Occidental in Western Visayas Region; and Zamboanga Del Norte, Zamboanga Del Sur, and Zamboanga Sibugay in Zamboanga Peninsula Region.

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

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 Administration (PAGASA)