Philippine tropical cyclones

Severe Tropical Storm Siony nears Batanes

Acor Arceo
Severe Tropical Storm Siony nears Batanes

Image from NOAA

PAGASA says Severe Tropical Storm Siony (Atsani) is bringing damaging winds and heavy rain to Batanes and the Babuyan Islands

Severe Tropical Storm Siony (Atsani) could make landfall in or pass near the province of Batanes in the next 6 hours, warned the state weather bureau late Thursday evening, November 5.

The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) said in a bulletin released past 11 pm that Siony is already 170 kilometers east of Basco, Batanes.

The severe tropical storm is moving west northwest at 20 kilometers per hour (km/h).

It currently has maximum sustained winds of 100 km/h and gustiness of up to 125 km/h as of Thursday evening.

PAGASA said Siony is likely to reach its peak intensity of around 110 km/h within 36 hours – still a severe tropical storm.

But the state weather bureau is not ruling out the possibility that Siony could strengthen into a typhoon, which is classified as having maximum sustained winds of 118 to 220 km/h. (READ: FAST FACTS: Tropical cyclones, rainfall advisories)

These areas remain under tropical cyclone wind signals as of 11 pm on Thursday:

Signal No. 2
  • Batanes
  • Babuyan Islands
Signal No. 1
  • northern part of mainland Cagayan (Santa Ana, Gonzaga, Lal-lo, Allacapan, Santa Teresita, Buguey, Camalaniugan, Aparri, Ballesteros, Abulug, Pamplona, Sanchez-Mira, Claveria, Santa Praxedes)
  • northern part of Apayao (Santa Marcela, Luna, Calanasan)
  • northern part of Ilocos Norte (Adams, Pagudpud, Bangui, Dumalneg, Burgos, Vintar, Pasuquin, Bacarra)

PAGASA said areas under Signal No. 2 are already experiencing damaging gale- to storm-force winds, while those under Signal No. 1 have strong breeze to near gale conditions.

It added that although it is “more likely for Siony to remain a severe tropical storm during its passage over the Luzon Strait,” the possibility of raising Signal No. 3 remains since Siony might still become a typhoon.

Overnight until Friday, November 6, Siony will also bring moderate to heavy rain to areas under Signal No. 2 and light to moderate rain – possibly heavy at times – to areas under Signal No. 1. Floods and landslides may occur.

PAGASA added that in the next 24 hours, there is a “minimal to moderate risk” of storm surges 1 to 2 meters high in the coastal areas of Batanes and the Babuyan Islands.

Travel is risky in certain seaboards in the next 24 hours.

  • areas under Signal Nos. 1 and 2 – rough to high seas (waves 3 to 8 meters high), risky for all vessels
  • areas under a gale warning – rough to very rough seas (waves 3 to 4.5 meters high), risky for small vessels

There will also be moderate to rough seas, with waves 1.5 to 3 meters high, here:

  • western seaboard of Central Luzon
  • eastern seaboards of Southern Luzon, Visayas, and Mindanao

PAGASA advised small vessels to take precautionary measures, and “inexperienced mariners” to avoid such waters.

Siony is expected to leave the Philippine Area of Responsibility (PAR) on Friday afternoon or evening.

By Saturday, November 7, it may move toward the Paracel Islands area in the South China Sea.

After leaving PAR, Siony may also gradually weaken.

Forecast track of Severe Tropical Storm Siony (Atsani) as of November 5, 2020, 11 pm.
Image from PAGASA

Meanwhile, the low pressure area (LPA) outside PAR that PAGASA has been monitoring is now 1,600 kilometers east of the Visayas.

It could enter PAR on Friday afternoon or evening, then possibly reach Eastern Visayas on Saturday afternoon or evening.

The LPA may also develop into a tropical depression within 48 to 72 hours. If it does, it would be given the local name Tonyo.

Siony is already the Philippines’ 19th tropical cyclone for 2020.

An average of 20 tropical cyclones form within or enter PAR each year. (READ: LIST: PAGASA’s names for tropical cyclones in 2020)

These are PAGASA’s latest estimates for the number of tropical cyclones inside PAR in the next 6 months:

  • November 2020 – 1 to 3
  • December 2020 – 2 or 3
  • January 2021 – 0 or 1
  • February 2021 – 0 or 1
  • March 2021 – 0 or 1
  • April 2021 – 0 or 1

In early October, the state weather bureau warned Filipinos to expect more rain in the coming months due to the onset of La Niña–

Add a comment

Sort by

There are no comments yet. Add your comment to start the conversation.


Acor Arceo

Acor Arceo is the head of copy and editorial standards at Rappler. Trained in both online and TV newsrooms, Acor ensures consistency in editorial standards across all sections and also supervises Rappler’s coverage of disasters.