TROPICAL DEPRESSION Luis intensified across northern Luzon on Monday, prompting the state weather bureau to raise Tropical Cyclone Wind Signal No. 1 over several provinces while issuing heavy rainfall warnings for nearly 20 areas.
In its 11 a.m. bulletin, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) placed Isabela, Quirino, the central and eastern portions of Cagayan and the eastern and southern portions of Apayao under Signal No. 1.
The wind signal was also raised over the eastern portions of Kalinga, Mountain Province and Ifugao, as well as the northern portion of Aurora.
PAGASA said strong winds associated with Luis could pose a minor threat to life and property in affected areas.
As of 10 a.m., the center of the tropical depression was estimated at 165 kilometers east of Echague, Isabela. It was carrying maximum sustained winds of 45 kilometers per hour (kph), gusts of up to 55 kph and moving northward at 15 kph.
The weather bureau said Luis was forecast to move generally northwestward and could make landfall or pass close to Northern Luzon on Monday night or early Tuesday before turning east-northeastward away from the Philippine landmass.
PAGASA also warned of heavy to intense rainfall from Monday until Tuesday noon due to the combined effects of the tropical depression and the southwest monsoon.
A red rainfall warning was issued over Pangasinan, where more than 200 millimeters (mm) of rain were expected, raising the risk of widespread flooding and landslides.
Orange rainfall warnings were raised over La Union, Tarlac, Zambales and Bataan, where accumulated rainfall of 100 mm to 200 mm could trigger flooding and landslides.
Yellow rainfall warnings were issued over Ilocos Sur, Benguet, Ifugao, Mountain Province, Nueva Vizcaya, Quirino, Nueva Ecija, Aurora, Bulacan, Isabela, Pampanga, Metro Manila, Cavite and Batangas. These areas may receive 50 mm to 100 mm of rainfall, which could cause flooding in low-lying areas and landslides in vulnerable locations.
PAGASA said Luis was expected to remain a tropical depression for most of the forecast period before weakening into a remnant low by Wednesday and eventually being absorbed by Tropical Cyclone Dolphin.
The weather bureau also said the southwest monsoon, enhanced by Luis, could bring strong to gale-force wind gusts across most of Luzon and the Visayas through Tuesday, with the affected area expected to expand to much of the country by Wednesday. — Edg Adrian A. Eva