Philippines: Typhoon Rai makes landfall in Surigao del Norte Province Dec. 16, continues to track westward across central regions /update 6

Event

Typhoon Rai (known locally in the Philippines as Odette) was tracking westward across the central Philippines late Dec. 16 after making its first landfall in Surigao del Norte Province earlier in the afternoon. The storm made additional landfalls over Dinagat Islands, Southern Leyte, Bohol, and Cebu provinces Dec. 16. As of 20:00 PHT, the storm's center of circulation was approximately 615 km (382 miles) southeast of Manila. Forecast models indicate the system will slightly weaken over the coming hours as it tracks westward and makes further landfalls over parts of Central Visayas and Western Visayas regions late Dec. 16 into early Dec. 17. Rai is forecast to make another landfall over northern Palawan island after transiting the Sulu Sea Dec. 17. The system will maintain typhoon strength as it subsequently enters the South China Sea late Dec. 17. Rai will then likely strengthen as it gradually turns northwestward before rapidly weakening into a tropical storm as it tracks further northward and passes west of the Paracel Islands Dec. 20. Rai will weaken further as it takes a turn to the northeast, passing southeast of Hainan Province, China, early Dec. 21. Some uncertainty remains in the track and intensity forecast, and changes could occur over the next few days.

Authorities have ordered preemptive evacuations for at least 98,000 people across Caraga, Central Visayas, Eastern Visayas, and Northern Mindanao regions ahead of the storm. Hundreds of schools and offices have been temporarily closed in these regions. Further evacuations are likely across the central Philippines in the coming hours and days as Typhoon Rai impacts the region. As of late Dec. 16, there were initial reports of power outages and flooding, including in Southern Leyte Province and Cagayan De Oro, Misamis Oriental Province, but no immediate reports of casualties. However, the true extent of the storm's impact is likely to become more clear in the coming days once it has passed and authorities are able to conduct damage assessments.

Government Advisories
As of late Dec. 16, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) had issued the following warnings:

• Tropical Cyclone Wind Signal (TCWS) 4: western Bohol, central and southern Cebu, northern and central Negros Oriental, and central and southern Negros Occidental provinces.

• TCWS 3: northern Palawan (including Cagayancillo and Cuyo Islands), southwestern Leyte, western Southern Leyte, northern Cebu (including Camotes Islands), the rest of Bohol, the rest of Negros Oriental, Siquijor, northern Negros Occidental, Guimaras, southern Iloilo, and southern Antique.

• TCWS 2: Surigao del Norte, Dinagat Islands, northern Surigao del Sur, Agusan del Norte, northern Agusan de Sur, Camiguin, Misamis Oriental, Misamis Occidental, northern Bukidnon, Lanao del Norte, far northern Zamboanga del Norte, the rest of Leyte, the rest of Southern Leyte, Biliran, the rest of Cebu (including Bantayan Islands), the rest of Negros Occidental, Northern Samar, Eastern Samar, Samar, Masbate (including Ticao and Burias islands), Sorsogon, Albay, Romblon, Aklan, Capiz, the rest of Iloilo, the rest of Antique, Oriental Mindoro, Occidental Mindoro, and the rest of Palawan (including the Calamian and Kalayaan islands).

• TCWS 1: Catanduanes, Camarines Norte, Camarines Sur, Marinduque, southern Quezon, Batangas, the rest of Surigao del Sur, the rest of Agusan del Sur, the rest of Bukidnon, Lanao del Sur, the rest of northern Zamboanga del Norte, the rest of northern Zamboanga del Sur, and northern Zamboanga Sibugay.

Authorities have warned of heavy-to-torrential rainfall over Central Visayas and Western Visayas Dec. 16-17, while moderate-to-heavy rainfall is likely across Eastern Visayas, Zamboanga del Norte, Lanao del Norte, Bicol, and Palawan through early Dec. 17. There is a moderate-to-high risk of storm surge of up to 3 meters (10 feet) which may cause flooding in low-lying coastal areas in Central Visayas Region as well as in Iloilo, Antique, Guimaras, Negros Occidental, and northern Palawan provinces.

Authorities will probably issue new warnings or update existing advisories throughout the system's progression in the coming days. Weather warnings could remain active even after the system's immediate threat has diminished, as some areas may still be highly susceptible to rain-induced hazards. Officials may announce additional evacuations if weather conditions prove particularly hazardous.

Hazardous Conditions
Typhoon Rai will likely continue to bring heavy rainfall, strong winds, and rough seas to most of the Visayas, southern Luzon, and northern Mindanao regions of the Philippines in the coming days. Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, and rivers, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Rain-induced landslides are possible in steeply sloped terrains. Flooding could isolate some communities for several days. Prolonged sea swells and storm surge generated by the system could result in coastal flooding. Persistent onshore flow could make it difficult for surge to recede and for water levels to decrease in coastal river catchments.

In addition to forecast heavy rain, flooding, and storm surge, the storm could produce damaging wind gusts. Widespread and prolonged power outages due to uprooted trees and toppled utility lines are possible.

Transport
Inclement weather associated with the storm could trigger localized business, transport, and utility disruptions. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports. Tudgan Airport (TBH) in Romblon Province was notably closed as of Dec. 15, as well as 59 seaports. The Manila International Airport Authority (MIAA) reported that as of mid-Dec. 16, over 100 domestic flights had been canceled, with hundreds more expected to be affected nationwide.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after weather conditions have improved. If there is severe damage to infrastructure, repair or reconstruction efforts may exacerbate residual disruptions.

Advice

Activate contingency plans in areas where officials forecast tropical storm or typhoon conditions. Heed all evacuation orders. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the high potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and any necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil-water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

Joint Typhoon Warning Center
Philippine Atmospheric, Geophysical and Astronomical Services Administration