Typhoon Goni


Typhoon Goni, named Rolly by PAGASA, was an extremely powerful and destructive tropical cyclone that made landfall in the Philippines as a Category 5-equivalent super typhoon in late October 2020. It is the strongest tropical cyclone on record by one-minute maximum sustained winds at landfall. The name "Goni" means swan in Korean. The nineteenth named storm, ninth typhoon, and second super typhoon of the 2020 Pacific typhoon season, Goni originated as a tropical depression south portion of Guam on October 26. It was then named as Tropical Storm Goni on October 27. On the next day, Goni explosively intensified over the Philippine Sea, becoming a Category 5–equivalent super typhoon on October 30. Goni maintained Category 5 strength for over a day, before making landfall in Catanduanes at peak intensity, with 10-minute sustained winds of, and one-minute sustained winds of, with a minimum central pressure of 905 hPa. It was the most intense tropical cyclone worldwide in 2020.
Following its first landfall, Goni rapidly weakened while it moved over the Sierra Madre mountain range of the Philippines. The storm brought severe flash flooding to Legazpi, as well as lahar flow from the nearby Mayon Volcano. There were widespread power outages as well as damaged power and transmission lines in Bicol. Crops were also heavily damaged. Over 390,000 out of 1 million evacuated individuals have been displaced in the region. Due to the extreme wind speed of the typhoon, two evacuation shelters had their roofing lost. Debris and lahars had also blocked various roads, as well as rendering the Basud Bridge impassible. In Vietnam, where Goni made landfall as a tropical depression, there was flooding in numerous areas, as well as eroded and damaged roads. This exacerbated the 2020 Central Vietnam floods, leaving additional estimated damages of ₫543 billion. Overall, the typhoon killed at least 32 people and caused at least ₱20 billion worth of damage. The COVID-19 pandemic was also a concern for people in evacuation centers.
After Goni moved into the South China Sea, it weakened to a tropical storm. It started to move generally westward towards Vietnam. It eventually reached the country late on November 5 as a tropical depression, bringing heavy rain and gusty winds. International relief from several countries as well as the United Nations followed soon after the typhoon moved away from the Philippines. The relief included donations totaling up to $11.48 million and protection from the pandemic, among other items.

Meteorological history

After Typhoon Molave devastated the Philippines, the Japan Meteorological Agency announced the formation of a new tropical depression in the Pacific Ocean, west of the Mariana Islands, on October 27. Given its proximity to the Philippine Area of Responsibility, along with its westward forecasted track, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration also began issuing advisories on the newly formed system. By the next day, the Joint Typhoon Warning Center had also followed and upgraded the system into a tropical depression. The storm had good outflow and structure as it approached the PAR.
As the system continued tracking westward under favorable conditions in the Pacific Ocean, the JMA and JTWC upgraded the system into a tropical storm, with the JMA assigning the name Goni to the intensifying system. The PAGASA followed with an upgrade to a severe tropical storm a few hours later. Due to the warm waters surrounding the storm, the system underwent rapid intensification and became a typhoon on October 29. On October 29, at 09:30 UTC, Goni entered the PAR and was named Rolly by the PAGASA. Early on the following day, the system was declared a super typhoon by the JTWC a few hours later, the second super typhoon of the season, before further intensifying into the only Category 5-equivalent super typhoon of the season by 06:00 UTC on October 30. After undergoing a brief eyewall replacement cycle on October 31, which is a typical process for a storm of such high intensity, it resumed intensifying, with the JTWC, JMA, and Satellite Analysis Branch all assessing Dvorak technique T-numbers of 8.0, the highest on the scale. On this basis, the JTWC estimated 1-minute sustained winds of, tying with Haiyan in 2013, Meranti in 2016 and Surigae in 2021 as the highest reliably estimated in the Eastern Hemisphere. Meanwhile, the JMA estimated a central barometric pressure of 905 hPa for the storm, while the JTWC estimated a minimum central pressure of 884 hPa.
File:Goni 2020-10-30 0444Z.jpg|thumb|right|Typhoon Goni near its initial peak intensity over the Philippine Sea on October 30, showing a very clear pinhole eye.
At 18:00 UTC on October 31, hours before Goni's first landfall, PAGASA upgraded Goni into a super typhoon. This was the second time that the PAGASA declared a system as a super typhoon since its introduction of the revised tropical cyclone intensity scale, the first being Haima in 2016. This is also the second time that the highest wind warning level, Signal #5, was raised in the Philippines as per the revised tropical cyclone wind signals. At 20:50 UTC on October 31, Goni made landfall in Bato, Catanduanes, Philippines, at peak intensity, as a Category 5-equivalent super typhoon. The JMA and PAGASA both reported 10-minute sustained winds of and, respectively, while the JTWC estimated 1-minute sustained winds of at the time of landfall. By 1-minute sustained winds, this made Goni the strongest recorded tropical cyclone to ever make landfall anywhere in the world. Around 24 minutes after landfall, a minimum pressure of was recorded by a weather station in Virac as Goni passed directly over it. Goni made additional landfalls in Tiwi, Albay at 23:20 UTC and San Narciso, Quezon at 04:00 UTC, on November 1. Goni then made its fourth and final landfall in the Philippines in Lobo, Batangas at 09:30 UTC. Interaction with land, plus an increase in wind shear caused Goni to rapidly weaken and it emerged over the South China Sea as a minimal tropical storm.
Before exiting the PAR, Goni slightly reintensified, but further development was hampered by unfavorable conditions. The system exited the PAR at 12:00 UTC on November 3. Goni's convection decoupled from its low-level circulation as a result of anticyclonic shear generated by the nearby Tropical Storm Atsani from Northern Luzon, before making landfall in Vietnam on November 6. Goni rapidly weakened after landfall, degenerating into a trough by 00:00 UTC on the next day. Goni's remnant trough then brought rain and more flooding to an already rain-stricken Vietnam from previous Linfa, Nangka, Ofel, and Molave, which had all struck the same region a few weeks earlier.

Preparations

Philippines

The Bicol Regional Disaster Risk Reduction and Management Council issued a no-sail policy that was put in place on October 29. The Philippine Coast Guard stopped giving travel permits to sea vessels bound for the Polillo Island. On October 30 at 8:00 PHT, authorities of Quezon placed the province in red alert in preparation for the storm, which requires operation and monitoring teams to be available at all times as the typhoon worsens. At the same time, the Camarines Norte Incident Management Team began evacuating 35,000 families, around 159,000 people, from high-risk areas, including coastal villages inside the province's bayside capital, Daet. On the same day, the NDRRMC raised a nationwide red alert in preparation for the storm's impact.
The Research Institute for Tropical Medicine, one of the largest COVID-19 sample testing laboratories in the country, announced a temporary suspension of operations on November 1 and 2 in order to mitigate damage to their building and equipment. As the typhoon neared the country, the Philippine Institute of Volcanology and Seismology had issued advisories warning of possible lahar contamination of nearby rivers and drainage areas near Mount Pinatubo, the Mayon Volcano, and the Taal Volcano.
On the morning of the October 31, less than 24 hours before the typhoon made landfall, PAGASA raised a Signal #3 tropical cyclone warning signal for Catanduanes, with the same signal being raised for the northeastern portions of both Albay and Camarines Sur a few hours later. Local governments across Camarines Sur began forced evacuations, with the province's Provincial Disaster Risk Reduction and Management Council expecting the evacuation of 20,000 families before noon. By noon, the Camarines Norte government had evacuated 6,645 individuals from 75 villages out of a planned 159,000. Food packs worth 8.3 million, non-food items worth 26.42 million, and 3 million in stand-by funds were prepared in the Bicol Region by the Department of Social Welfare and Development, together with local disaster response agencies. Evacuation centers in Aurora were also prepared, with some school buildings designated for use as shelters. In Metro Manila, mayors of the constituent cities have begun their own preparations for the upcoming typhoon, such as halting construction and ordering the dismantling of tents and other outdoor structures. The Disaster Risk Reduction and Management Office of Manila has prepared rescue boats for potential rescue operations.
By evening, PAGASA raised the first Signal #4 tropical cyclone warning of the year in Catanduanes and the eastern portion of Camarines Sur, and in the northern portion of Albay a few hours later. By the end of the day, almost a million individuals were evacuated: 749,000 from Albay and 200,000 from Camarines Sur; this exceeded the number of people evacuated ahead of Typhoon Haiyan in 2013. The Manila International Airport Authority announced that Ninoy Aquino International Airport would be temporarily closed for 24 hours, beginning 10:00 am the following day. Closures in ports left 1,300 passengers stranded in Bicol and Eastern Visayas. Many existing evacuation centers, usually basketball courts and multi-purpose halls, were already being used by victims of the COVID-19 pandemic, which complicated evacuation for those affected by the typhoon.
By the early morning of November 1, hours prior to Goni's landfall, the PAGASA raised Signal #5, the highest tropical cyclone warning signal, in Catanduanes, Albay, and the eastern portion, and eventually the whole, of Camarines Sur. On the morning of Goni's first landfall, the PAGASA raised Signal #4 for the country's capital, Metro Manila. All rail lines, including the Manila Light Rail Transit System and the Manila Metro Rail Transit System suspended operations, along with the EDSA Busway and the PNR Metro Commuter Line.
A total of 480,174 individuals were preemptively evacuated in 8 regions.