Nine years ago on Nov. 8, Typhoon Yolanda (international name: Haiyan) swept across the Visayas and Palawan. In terms of one-minute sustained winds, as estimated by the Hawaii-based Joint Typhoon Weather Center, it was the most intense tropical cyclone worldwide in 2013. In 2020, typhoon Goni’s stronger sustained winds relegated Yolanda to being the second strongest land falling tropical cyclone on record.
I could not forget “Yolanda,” as I was serving then as Press Secretary to President Benigno ‘Noynoy’ Aquino III.
In a special radio-television broadcast on Nov. 7, President Aquino urged the people to follow the warnings issued by the weather bureau including the storm surge warning. Translated into English, this is what he said, according to Malacañang’s Official Gazette:
“As you know, Yolanda has entered the Philippine Area of Responsibility. As with last year’s Typhoon Pablo, I thought it best to speak to you to emphasize the gravity of the calamity our countrymen will face in these coming days, and to ask of everyone cooperation and solidarity.
“Storm signal number 4 has been — and will be — raised over some areas because of this typhoon. Current data indicates that Yolanda will be stronger than Pablo; we pray that because of its speed, it will not linger over any of our provinces and intensify the damage. The typhoon has a 600-kilometer diameter. We expect it to make landfall on Samar and Leyte by midnight; it will traverse the provinces of Masbate, Cebu, Panay, Romblon, Mindoro, and Palawan, before it completely leaves the Philippine Area of Responsibility on Saturday night. Aside from strong winds, rain, the overflowing of our rivers, and the possibility of lahar in areas near the Mayon and Bulusan volcanoes, we are likewise monitoring the threat of storm surges in more than a hundred areas: Storm surges are expected in Ormoc, Ginayangan, Ragay Gulf in Albay, and Lamon Bay in Atimonan. Waves in these areas may reach five to six meters.” (Emphasis supplied.)
As described by DOST-PAG-ASA: “Storm surge is the sudden increase in sea water level associated with the passage of a tropical storm or typhoon. This is due to the push of strong winds on the water surface (wind setup), the piling up of the big waves (wave set up), pressure setup (storm central pressure) and astronomical tide moving toward the shore. This will happen at landfall or passage of a tropical storm or typhoon in a locality. This might be ahead, during or following the coming of strong or high winds of the storm.”
Storm surge was acknowledged in the disaster risk reduction management (DRRM) plan of Guiuan, Eastern Samar. It is known as the Philippines’ “eastern gateway” as it is often the first province on which typhoons make landfall. Guiuan’s local officials cobbled together a DRRM plan that included emergency provisions and contingencies. Surprisingly, however, Guiuan’s DRRM plan makes no mention of storm surge. By contrast, the DRRM plan of one of Guiuan’s barangays, Victory Island, identified storm surge as a hazard. In fact, the BDRRM plan described it as the third biggest hazard with a probability of four in five hitting the island (five most probable), and with an impact of three out of five (with five having the heaviest impact).”
In November 1984, Typhoon Undang, which took the same path as Yolanda, inflicted severe damage. Twenty nine years later, Yolanda came with its 215 kph wind strength and gustiness of 250 kph. Here’s a more detailed account of the storm surge brought on by Yolanda:
“It took on the Samar and Leyte islands and killed thousands with its five to seven meters height of storm surge. In Basey, Samar, those who were aware of the predicted rise in sea level expected the storm surge to be similar to that of Undang’s two-meter wave height. Back then, the term storm surge was not really used. During Typhoon Undang, one-story houses were able to withstand the ravages of the storm surge. Markings of the damage of the surge were visible along the seawall of Basey, Samar according to a local resident. But Typhoon Yolanda damaged the entire seawall.
“According to the stride team of PAGASA the recorded height of the storm surge in the province of Samar specifically in the two coastal barangays of Basey reached up to 5.39 to 5.53 meters. The surge barreled everything on its path, it destroyed even the concrete houses and two-story buildings near the coastline. Emphasis supplied.)
Did the people get the warning messages about the storm surge on time? If they did, were the messages understood and acted upon? Again, the NDRRMC reflects:
Yolanda had barely left Eastern Visayas when these questions began gaining traction not only in the news media but among government officials and disaster risk practitioners as well given the horrendous number of casualties attributed to a phenomenon called storm surge. In the province of Leyte, Tacloban City alone accounted for about 2,678 of the total number of fatalities recorded in the entire region with many reported to have been killed by the storm surge.
“It was obvious, however, that the public and many local governments could not imagine Yolanda’s magnitude and proportions. Although they had been warned about the impending arrival of a super typhoon, many were not alarmed because they had experienced, and lived through, seriously strong and destructive weather events before. They said they were also warned about a possible storm surge but they did not know what it meant, let alone understood its deadly potential. Some emergency warning officers, in fact, avoided using the term storm surge as they themselves were hard put explaining it clearly.”