Tropical Cyclone Wind Signals

This article is about the tropical cyclone warning system used in the Philippines. For the similarly named warning system in Hong Kong, see Hong Kong tropical cyclone warning signals. For other tropical cyclone warning systems, see Tropical cyclone warnings and watches.

Map of Tropical Cyclone Wind Signals hoisted in most of Luzon, Philippines due to Typhoon Noru (Karding) at 5:00 PM PHT on September 25, 2022

The Tropical Cyclone Wind Signals (TCWS, or simply wind signals or signals;[a] Filipino: Mga Babala ng Bagyo) are tropical cyclone alert levels issued by the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) to areas within the Philippines that may be affected by tropical cyclone winds and their associated hazards.[1]

PAGASA's TCWS system is activated when a tropical cyclone is inside or near the Philippine Area of Responsibility and is forecast to affect the Philippine archipelago. It is a tiered system with five numbered levels, with higher numbers associated with higher wind speeds and shorter "lead times", which are periods within which an expected range of wind strength is expected to occur.[1][2][3] TCWS signals are issued for specific localities at the provincial or city/municipal level. They are escalated, de-escalated or lifted depending on the expected strength of winds and the movement of the tropical cyclone relative to the affected areas.[4][1]

The TCWS system is the consequence of decades of evolution of early warning systems for tropical cyclones in the Philippines. The first tropical cyclone warning in the country was issued in July 1879. In 1931, the earliest formalized warning system for tropical cyclones was implemented by PAGASA's predecessor, the Philippine Weather Bureau.[5] In the late 20th century, this system gradually became the more familiar four-tiered public storm warning signal system.[6] It was subject to further revisions after the catastrophic onslaught of Typhoon Haiyan (Yolanda) in 2013, which prompted the addition of a fifth warning level to emphasize extreme tropical cyclone winds.[7][8] The current version of the TCWS was implemented in 2022.[9][10][11]


Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).

  1. ^ a b c "Tropical Cyclone Wind Signal". Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA). Retrieved August 23, 2022.Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ PAGASA. "Philippine Tropical Cyclone Warning Signal". Archived from the original on 2022-06-30. Retrieved 2022-06-30.
  3. ^ PAGASA. "The Modified Philippine Public Storm Warning Signals". PAGASA Kidlat. Archived from the original on 2008-09-30. Retrieved 2008-09-30.
  4. ^ Arceo, Acor (December 3, 2019). "Why is it now called tropical cyclone 'wind' – and not 'warning' – signals?". Rappler. Archived from the original on August 23, 2022. Retrieved August 23, 2022.
  5. ^ "Annual Report on Philippine Tropical Cyclones (2017)" (PDF). Philippine Atmospheric, Geophysical, and Astronomical Services Administration. March 2019. Archived (PDF) from the original on January 12, 2024. Retrieved January 12, 2024.
  6. ^ Esperanza O. Cayanan (July 20, 2015). "The Philippines modified its Tropical Cyclone Warning System" (PDF). World Meteorological Organization (WMO).
  7. ^ de la Cruz, Gwen (May 21, 2015). "PAGASA adds Storm Signal No. 5 to storm warning system". Rappler. Archived from the original on April 26, 2019. Retrieved April 26, 2019.
  8. ^ Sauler, Erika (May 21, 2015). "Pagasa adds storm signal No. 5 for supertyphoons". Inquirer.net. Philippine Daily Inquirer. Archived from the original on August 23, 2022. Retrieved August 23, 2022.
  9. ^ "Press Release: DOST-PAGASA modifies Tropical Cyclone Wind Signal (TCWS) system". Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA). March 23, 2022. Archived from the original on August 23, 2022. Retrieved August 23, 2022.
  10. ^ Arceo, Acor (March 23, 2022). "PAGASA changes super typhoon definition, wind signals". Rappler. Archived from the original on August 23, 2022. Retrieved August 23, 2022.
  11. ^ Sarao, Zacarian (March 24, 2022). "Pagasa revises definition of 'super typhoon,' signal system". Inquirer.net. Philippine Daily Inquirer. Archived from the original on August 23, 2022. Retrieved August 23, 2022.