As Super Typhoon “Uwan” exited land as a diminished storm on Monday, November 10, a number of posts on social media thanked the mountain ranges of Luzon for “protecting” the island.
These supposed “guardians of Luzon” were the Sierra Madre, the country’s longest mountain range stretching from Cagayan to Quezon in eastern Luzon; the Cordillera in north central Luzon; the Caraballo mountains nestled between the two ranges; and the Zambales mountains to the west.
But do they indeed serve as barriers against typhoons? The science shows the answer is yes, but not quite.
Satellite images of “Uwan” indeed showed the eye of the storm closing as it made landfall on Sunday evening, November 9.
But on the ground, coastal areas such as Aurora and Isabela still suffered immense damage.
Storm chaser Josh Morgerman — who came to Aurora to document the typhoon — called out what he described as misinformation on social media about the impact of the Sierra Madre.
“The Sierra Madre Mountains weaken typhoons. But this only happens after communities on Luzon’s east coast take the full force,” he said in a later post.
Weather forecasts usually predict storms to decrease strength once they hit land, an effect seen previously in northern Luzon with Typhoon “Pepito” in 2024.
A 2023 study by meteorologists Dr. Gerry Bagtasa and Dr. Bernard Alan Racoma gives a more nuanced answer to public perception on the effect of Luzon’s mountains.
The researchers simulated the impact of storms whether the Sierra Madre and Cordillera were in Luzon or not.
It showed the mountain ranges did not significantly weaken the storms upon landfall and during their first six hours over land.
The Cordillera was also found to have a bigger effect on reducing the strength of storms than the Sierra Madre.
Meanwhile, it was only in the Cagayan Valley region in the northeast that the Sierra Madre served as an “effective barrier” to winds and rainfall.
However, the story is different for low-lying areas like Metro Manila, where the Sierra Madre actually had a negative impact — increasing rainfall which contributes to floods. A case in point was the flooding from Typhoon “Ondoy” in 2009.
Thus, the scientists cautioned the public against idealizing the mountain ranges.
“Relying on [them] as barriers to [tropical cyclones] is flawed, inaccurate and potentially dangerous as this may lead to complacency,” they wrote.
The research acknowledged long-standing beliefs about the placement of the mountains from Filipino folklore which led to this perception.
Still, they said, the more crucial conversation to be had is not how mountains like the Sierra Madre and Cordillera protect us, but how we protect these natural resources and their unique flora and fauna against human-made threats like irresponsible logging and mining.
This comes as scientists also observe a downtrend in the number of storms reaching the Philippines. But the storms that do are getting bigger and stronger, leading to more super typhoons like “Uwan” — all an ongoing effect of climate change.
The cost of lives and livelihood is also growing worse, hence the need for long-term preparation to mitigate these effects on Filipinos.
Experts add, this includes taking care of the environment not just for their help against the effects of storms and flooding, but more so for their role in keeping humanity and the planet alive. (ABS-CBN News)