Several communities near Kanlaon Volcano in Negros Island are advised to prepare for possible lahars due to heavy rainfall from Tropical Storm Nokaen, locally named Ada, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).
In an 11:00 a.m. advisory, PHIVOLCS said the forecasted rains from Ada may trigger lahars and muddy run-off in rivers and drainage areas around the volcano.
“Prolonged heavy rainfall could generate life-threatening lahars and sediment-laden streamflows on major channels draining the southern, western, and eastern slopes of Kanlaon Volcano,” PHIVOLCS said.
The bureau explained that post-eruption lahars can form when heavy rain washes away loose volcanic debris from recent eruptions and ashfall.
Meanwhile, non-eruption lahars can occur when recently landslide-exposed or weakened slopes, like those affected by Super Typhoon Tino in November 2025, collapse and send debris into rivers, threatening downstream communities.
PHIVOLCS said that communities that may be affected by lahars and sediment-laden streamflows include Bago City, La Carlota City, La Castellana, Moises Padilla, and San Carlos City in Negros Occidental.
It is also possible in Canlaon City in Negros Oriental, particularly along rivers and creeks such as Ibid, Cotcot, Talaptapan, Malaiba, Panubigan, Buhangin–Indurayan, Najalin, Inyawan, Maragandang, Panun-an, Intiguiwan, Camansi, Maao, Tokon-tokon, Masulog, Binalbagan, Taco, and Linothangan.
“These communities, as well as those further downstream of the above channels, are advised to prepare in case evacuation becomes necessary and to avoid traversing affected streams, even those farther downslope of the volcano,” PHIVOLCS said.
The bureau also reminded that Kanlaon lahars have been proven strong enough to carry large volumes of gravel and boulders, as shown during Super Typhoon Tino, posing a serious threat to communities.
Alert Level 2 remains in effect at Kanlaon Volcano, indicating increased unrest, according to PHIVOLCS.— Edg Adrian A. Eva