The Department of Science and Technology (DOST) on Monday, Nov. 10 said that while the Sierra Madre Mountain Range helps reduce the strength of typhoon winds in Luzon, it does not provide complete protection from their destructive effects.

Citing a 2023 study by Dr. Gerry Bagtasa and Dr. Bernard Alan Racoma published in the Philippine Journal of Science, the DOST explained that the Sierra Madre can slightly weaken or slow down winds brought by typhoons, especially those entering the northeastern part of Luzon.

However, the researchers found that the damage caused by heavy rains and flooding remains greater than that from strong winds.

“Maaaring sabihing nakatutulong ang Sierra Madre Mountain Range bilang panangga sa mga bagyo sa Luzon sapagkat may kakayahan itong bahagyang pahinain o bagalan ang lakas ng hanging dala ng bagyo—lalo na sa hilagang-silangang bahagi ng rehiyon. Gayunman, hindi ito nagbibigay ng ganap na proteksyon laban sa matitinding epekto ng mga ito,” the DOST said in a social media post.

(It can be said that the Sierra Madre Mountain Range helps serve as a shield against typhoons in Luzon as it has the ability to slightly weaken or slow down the strong winds brought by typhoons—especially in the northeastern part of the region. However, it does not provide full protection from their severe impacts).

The study found that a typhoon’s strength does not significantly weaken during the first six hours after landfall, even when mountain ranges are present.

It also showed that the Cordillera Mountain Range has a stronger effect in reducing wind strength than the Sierra Madre.

The researchers said the Sierra Madre can decrease wind strength by about 1 to 13 percent but can also increase rainfall on its western side, including Metro Manila, by 23 to 55 percent.

In contrast, in Cagayan Valley, the mountain range helps reduce both wind and rainfall, making it an effective “shield” for that part of Luzon.

The study also emphasized the need to protect the Sierra Madre from deforestation, mining, and other destructive activities, as it is home to rich biodiversity and serves as a vital source of the country’s natural resources.

The study’s findings are especially relevant in the aftermath of Super Typhoon Uwan (international name: Fung-wong), which crossed Luzon over the weekend.

Many Filipinos have expressed gratitude to the Sierra Madre for reportedly “weakening” the typhoon as it made landfall over Aurora and passed through the mountain range.