Tropical cyclone wind signal No. 1 has been raised over some areas in Cagayan province on Wednesday due to the approaching tropical storm "Siony" (international name "Atsani") towards the extreme part of Northern Luzon.
The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) hoisted Signal No. 1 over the northeastern portion of mainland Cagayan (Santa Ana, Gonzaga) and the eastern portion of Babuyan Islands (Balintang Island, Babuyan Island, Didicas Island, and Camiguin Island, including their adjoining islets) in its severe weather bulletin issued at 5 a.m.
PAGASA said strong to gale-force winds with "higher" gusts may affect Batanes, Babuyan Islands, and the northern coastal areas of Cagayan and Ilocos Norte in the next 24 hours due to the northeasterlies enhanced by tropical storms "Siony" and "Rolly."
Based on available meteorological data, PAGASA said the highest wind signal to be raised will be Signal No. 2.
However, because intensification into the typhoon category remains a potential scenario at this time, the possibility of hoisting Signal No. 3 in areas near or along the projected track of the storm is not discounted.
"Siony's" location was estimated 700 kilometers east of Basco, Batanes around 4 a.m.
It is packing maximum sustained winds of 85 kilometers per hour (kph) and gustiness of up to 105 kph, while moving south-southwest slowly.
PAGASA said "Siony" may continue to move slowly or remain almost stationary in the next 12 hours.
Afterwards, the tropical storm will move generally west or west-northwest towards the Luzon Strait and extreme Northern Luzon.
"This will bring the center of 'Siony' over or very close to the Batanes and Babuyan Islands between Thursday evening and Friday morning. As such, a landfall scenario over these localities remains likely," PAGASA said.
"Siony" could also further intensify into a severe tropical storm in the next 24 hours and reach its peak intensity of 100 kph to 110 kph by Thursday prior to its close approach or landfall over extreme Northern Luzon.
However, intensification into the typhoon category is not ruled out at this time.
PAGASA warned of light to moderate with at times heavy rains over Aurora, Quezon, Camarines Norte, Camarines Sur, Catanduanes, and the eastern portions of Cagayan and Isabela due to the combined effects of the northeasterlies and the trough of "Siony."
The State weather bureau asked the public to be 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.
Those in areas that received significant rainfall from the recent tropical cyclones "Pepito," "Quinta," and "Rolly" were also advised to take extra precaution due to already saturated soil.
The combined effects of "Siony," "Rolly," and the enhanced northeasterlies will bring rough to very rough seas with waves that may reach 2.8 to 5.0 meters over the entire seaboards of Northern Luzon, northern seaboard of Camarines Sur, northern and eastern seaboards of Catanduanes, and seaboards of Aurora, Camarines Norte, Kalayaan Islands, and northern Quezon (including the northern and eastern coastal waters of Polillo Islands).
Sea travel is risky over these waters, especially for those using small boats, PAGASA said.
Meanwhile, moderate to rough seas with wave heights up to 1.5 to 2.5 m will be experienced over the western seaboard of Central Luzon, eastern and western seaboards of Southern Luzon, and eastern seaboards of Visayas and Mindanao.
PAGASA advised mariners of small sea vessels to take precautionary measures when venturing out to sea, while inexperienced mariners were asked to avoid navigating in these conditions.
Based on the latest forecast track, Siony will leave the Philippine area of responsibility by Friday afternoon or evening.
Meanwhile, tropical storm Rolly (Goni) has already left the PAR on Tuesday evening.
The rest of Luzon may experience light rains due to the northeasterlies or the cold winds coming from the north, while the rest of the country may have rain showers due to localized thunderstorms.