Stormy weather is expected in extreme Northern Luzon as severe tropical storm "Siony" (international name "Atsani") is anticipated to make landfall or move close to Batanes within the next six hours.
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) estimated the location of Siony at 170 kilometers east of Basco, Batanes around 10 p.m. Thursday.
It has maintained its maximum sustained winds of 100 kilometers per hour (kph) near the center and gustiness of up to 125 kph.
Tropical cyclone wind Signal No. 2 remains hoisted over Batanes and Babuyan Islands, while Signal No. 1 was raised over the northern portion of mainland Cagayan (Santa Ana, Gonzaga, Lal-Lo, Allacapan, Santa Teresita, Buguey, Camalaniugan, Aparri, Ballesteros, Abulug, Pamplona, Sanchez-Mira, Claveria, Santa Praxedes), northern portion of Apayao (Santa Marcela, Luna, Calanasan), and northern portion of Ilocos Norte (Adams, Pagudpud, Bangui, Dumalneg, Burgos, Vintar, Pasuquin, Bacarra).
"Damaging gale to storm-force winds" will prevail in areas under Signal No. 2, while "strong breeze to near gale conditions" will affect areas under Signal No. 1.
PAGASA also warned of moderate to heavy rains over areas under Signal No. 2 and light to moderate with at times heavy rains over areas under Signal No. 1.
It asked the public to stay vigilant against possible flooding, including flash floods, and rain-induced landslides during heavy or prolonged rainfall, especially in areas that are highly susceptible to these hazards.
Due to Siony's strong winds, PAGASA also warned of "minimal to moderate" storm surge risk over the coastal areas of Batanes and Babuyan Islands in the next 24 hours.
Rough to high seas with waves that may reach 3.0 meters to 8.0 meters may also occur in areas under Signal nos. 2 and 1.
Sea travel has already been suspended in these areas.
After leaving the Philippine area of responsibility (PAR) on Friday afternoon or evening, PAGASA said Siony may turn southwestward by Saturday morning and accelerate over the sea to the west of southern Taiwan and then move over the West Philippine Sea towards Paracel Islands.