2020 Pacific typhoon season

Typhoon (JMA)
Category 3 typhoon (SSHWS)
Duration	May 10 – May 18
Peak intensity	155 km/h (100 mph) (10-min)  965 hPa (mbar)

After 4 consecutive months of inactivity in the Western Pacific basin, a low-pressure area was first noted on May 9 by the JTWC near Micronesia and was given a medium chance of developing into a tropical cyclone. The following day, the JMA declared that it had developed into a tropical depression to the east of Mindanao, Philippines and was expected to slowly move west. The JTWC then issued a Tropical Cyclone Formation Alert (TCFA) for the embryonic system just hours later while convection began to gradually obscure the center. Later that day, the PAGASA followed suit and upgraded the system to a tropical depression, assigning it the name Ambo, as it became the first tropical cyclone to enter their area of responsibility for 2020.[3][4] The system began to slowly drift westwards throughout the proceeding days,[5] gradually intensifying with occasional convective bursts occurring near the slightly elongated circulation. On the next day, the JTWC upgraded Ambo into a tropical depression, designating it as 01W.[6] The storm gradually intensified throughout the day, as signified by a well-defined rain band developing on the northwestern side, and began to turn north. At this time, the JMA upgraded 01W to a tropical storm and assigned it the first name of the year, Vongfong.[7] Shortly after, the JTWC followed and upgraded the system to tropical storm intensity.[8] Utilizing favorable conditions with low wind shear, 29-30 °C waters, and excellent outflow, Vongfong began to rapidly intensify by early May 13.[9] Shortly after, the JMA upgraded the system to a severe tropical storm. Soon after, the JTWC upgraded the storm to a Category 1 typhoon with 1-minute sustained winds of 130 km/h (80 mph) as the structure quickly improved. The PAGASA and JMA would then upgrade the system to a typhoon later in the day,[9] with the JTWC quickly upgrading the system to a Category 2 typhoon as the eye became clearer. A few hours later, Vongfong intensified to a category 3-equivalent typhoon.[10] Vongfong made an eyewall replacement cycle and weakened back into a Category 2 typhoon. Typhoon Vongfong quickly finished its eyewall replacement cycle and re-intensified back into a Category 3 typhoon east of Samar Island. At 12:15 pm PST on May 14, Vongfong made its first landfall in San Policarpo, Eastern Samar.[11] Vongfong gradually weakened shortly after, crossing over the Ticao Pass as it moved further inland near Sorsogon.[12] By the succeeding day, PAGASA recorded five more landfalls: hitting the islands of Dalupiri Island, Capul Island, Ticao Island, Burias Island, and San Andres, Quezon in Luzon Island's Bondoc Peninsula.[13] Ambo weakened into a Category 1 storm due to these multiple landfalls. The system further weakened on May 15, and was downgraded by both the JMA and PAGASA to a severe tropical storm,[14] with the JTWC downgrading it to a tropical storm as well. Severe Tropical Storm Vongfong then brought heavy rains and winds to the capital Metro Manila and other areas in Luzon. Then, Severe Tropical Storm Vongfong made its 7th landfall in Real, Quezon, and began to head further inland into Luzon, particularly Bulacan, continuing to deliver very heavy rainfall across the entirety of Central Luzon.[15][16] Severe Tropical Storm Vongfong further weakened and was downgraded by the JMA and the PAGASA into a tropical storm while it was inland Luzon. The weakening trend continued, and by May 16, Vongfong exited the landmass of Luzon into the waters of the West Philippine Sea, west of Ilocos Sur. After hitting many places in the Philippines, Tropical Storm Vongfong weakened into a low end-tropical storm. The JTWC then downgraded Vongfong into a tropical depression, and soon after that, they issued their final warning on the system, despite the JMA keeping it as a tropical storm. The PAGASA also downgraded Vongfong to a tropical depression, as Vongfong became very disorganized, and very damaged by the Luzon landmass. Soon, the agencies gave their final warning on Vongfong, as its low-level circulation center (LLCC) became exposed in the Luzon Strait.

In preparation for the incoming Typhoon Vongfong, Tropical Cyclone Wind Signal (TCWS) #3 warnings were issued for Northern Samar and the northern portion of Eastern Samar.[17] According to the NDRRMC, Typhoon Vongfong (Ambo) left ₱1.57 billion (US$31.1 million) worth of damages in agriculture, and left five dead, as of May 27.[18][19]

Tropical storm (JMA)
Tropical storm (SSHWS)
Duration	June 10 – June 14
Peak intensity	75 km/h (45 mph) (10-min)  996 hPa (mbar)

On June 10, the JMA began monitoring on a weak tropical depression that had developed to the east of the Philippine island of Samar in Visayas. During the next day, the PAGASA began tracking the system, giving the local name Butchoy.[20][21]According to PAGASA, Tropical Depression Butchoy then made its first landfall in Polillo Island in Quezon at 5:30pm PHT, and making its second landfall in Infanta, Quezon shortly thereafter. Soon after, the JTWC issued a Tropical Cyclone Formation Alert (TCFA) for Butchoy. The storm caused widespread flooding across the Philippines as it passed the Luzon landmass and enhanced the southwest monsoon. Soon afterward, the JTWC officially upgraded Butchoy to a tropical depression, and designated it 02W. As 02W (Butchoy) exited the Philippine landmass, the PAGASA lowered all TCWS warnings over the country. Butchoy then started to intensify in the West Philippine Sea, later becoming a tropical storm and receiving the name Nuri from the JMA on June 12. Then, the PAGASA issued their final warning on Butchoy (Nuri) as it exited the Philippine Area of Responsibility. Nuri then intensified further in the South China Sea, with the JMA analysing the storm's winds of 75 km/h (45 mph). By June 13, the JTWC upgraded Nuri to a tropical storm. However by the next day, both the JMA and JTWC downgraded Nuri back to a tropical depression, where the JMA issued their final warning on the system, shortly before making landfall near Yangjiang. The JTWC issued their final warning for Nuri several hours later.[22]

The PAGASA issued Tropical Cyclone Signal No. 1 for western Mindanao, southern Luzon, and Visayas on June 11 as Butchoy neared the Philippines.[23] The combination of the system and prevailing southwesterly winds brought showers and thunderstorms across the Philippines.[24] Heavy rainfall in Albay led to the activation of disaster risk management officials and other emergency assets.[23] The rains from the tropical depression prompted PAGASA to declare the start of the rainy season in the Philippines on June 12, 2020, which was also during the country's Independence Day.[25][26]

In Hong Kong, Nuri brought heavy rain. One person also drowned due to flooding.[27]

A tropical cyclone is named when it is judged to have 10-minute sustained windspeeds of 65 km/h (40 mph).[30] The JMA selected the names from a list of 140 names, that had been developed by the 14 members nations and territories of the ESCAP/WMO Typhoon Committee.[31] Retired names, if any, will be announced by the WMO in 2021; replacement names will be announced in 2022. The next 28 names on the naming list are listed here along with their international numeric designation, if they are used.

This season, PAGASA will use its own naming scheme for storms that will either develop within or move into their self-defined area of responsibility.[32] The names are taken from a list of names that were last used during 2016 and are scheduled to be used again during 2024.[32] All of the names are the same except Kristine, Leon, and Nika, which replaced the names Karen, Lawin, and Nina after they were retired.[32]