Philippines: Adverse weather forecast across central and northeastern regions through at least Dec. 4 /update 2

Severe weather is forecast across parts of the central and northeastern Philippines through at least Dec. 4. The Philippine Atmospheric, Geophysical, and Astronomical Administration (PAGASA) has warned of significant rainfall in the affected area over the coming days. Heavy to intense rainfall of 10-20 cm (4-8 inches) are likely over Quezon Province Dec. 2. Lesser rainfall totals of 5-10 cm (2-4 inches) are forecast across the rest of the affected area through Dec. 4. As of early Dec. 2, PAGASA has issued extreme general flood advisories (the second-highest level on a four-tier scale) across Bicol Region and severe general flood advisories across Calabarzon and Western Visayas regions. Officials could update and extend the coverage of weather alerts over the coming days.

Authorities have ordered preemptive evacuations for flooding and landslide-prone areas in Camarines Sur Province. Classes are suspended in parts of Bicol, Calabarzon, and Mimaropa regions.

Much of the Philippines is still recovering from severe flooding and landslides brought about by the succession of tropical systems moving across the region over recent weeks. Northern and central regions were the worst affected; however, records indicate the storm's effects in 17 of the country's 18 regions in recent weeks. Six storm systems have made landfall or passed close to the country since Oct. 24: Tropical Storm Trami (named Kristine in the Philippines) made landfall in Divilacan Town, Isabela Province, at around 00:30 Oct. 24; Tropical Storm Kong-rey (named Leon in the Philippines) made a close approach to northeastern Luzon Oct. 30-31; Tropical Storm Yinxing (named Marce in the Philippines) passed over the north coast of Luzon Nov. 7; Typhoon Toraji (named Nika in the Philippines) made landfall near Dilasag in Aurora Province early Nov. 11; Typhoon Usagi (named Ofel in the Philippines) passed over far northeastern Luzon and past the northern island regions of the Philippines Nov. 14; and finally Super Typhoon Man-yi (name Pepito in the Philippines) made landfall over Catanduanes Island late Nov. 16 and Dipaculao in Aurora Province the afternoon of Nov. 17. Further rainfall could lead to additional flooding and landslides as well as exacerbate the situation and hamper recovery efforts.

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 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 rain 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.

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. Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas with 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.