The 2013 Pacific typhoon season was a record-breaking and catastrophic season that was the most active since 1994, and the deadliest since 1975. It featured 31 named storms, 13 typhoons, and five super typhoons. The season's first named storm, Sonamu, developed on January 4 while the season's last named storm, Podul, dissipated on November 15. The season ran throughout 2013, though most tropical cyclones typically develop between June and November. Collectively, the storms caused 6,829 fatalities, while total damage amounted to at least $26.41 billion (USD).
In mid-July, Typhoon Soulik in July was the strongest tropical cyclone to affect Taiwan in 2013. In mid-August, Typhoon Utor cost US$3.55 billion worth of damage and killed 97 people, after carving a path of destruction across China and the Philippines. In mid-September, Typhoon Usagi struck China's Guangdong province and caused at least $4 billion in total damage. Two weeks later, Typhoon Fitow struck China's Fujian province and wrought over $10 billion worth of damage in total, making it, at that time, China's costliest storm in history.
The season's most powerful and deadliest storm was Typhoon Haiyan. Making landfall in the Philippines as a Category 5 super typhoon in early November, it wrought catastrophic damage and devastation across the country, particularly in the islands of Samar and Leyte, where extensive loss of life was recorded. With over 6,300 fatalities, Haiyan is the ninth-deadliest Pacific typhoon on record and the deadliest in Philippine history.
The scope of this article is limited to the Pacific Ocean to the north of the equator between 100°E and the 180th meridian. Within the northwestern Pacific Ocean, there are two separate agencies that assign names to tropical cyclones, which often results in a storm having two names. The Japan Meteorological Agency (JMA) will name a tropical cyclone should it be judged to have 10-minute sustained wind speeds of at least 65 km/h (40 mph) anywhere in the basin, whilst the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) assigns names to tropical cyclones which move into or form as tropical depressions in their area of responsibility, located between 115°E and 135°E and between 5°N and 25°N, regardless of whether or not the tropical cyclone has already been given a name by the JMA. Tropical depressions monitored by the United States' Joint Typhoon Warning Center (JTWC) are given a number with a "W" suffix.
Seasonal forecasts
During each season, several national meteorological services and scientific agencies forecast how many tropical cyclones, tropical storms, and typhoons will form during a season and/or how many tropical cyclones will affect a particular country. These agencies include the Tropical Storm Risk (TSR) Consortium of the University College London, Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) and the Vietnamese National Center for Hydro Meteorological forecasts (VNCHMF).
In early December 2012, the VNCHMF noted that a tropical depression or a tropical storm could form within December or January and affect Southern Vietnam. Within its January — June seasonal climate outlook, PAGASA predicted that two to three tropical cyclones were likely to develop and/or enter the Philippine area of responsibility between January and March while two to four were predicted for the April to June period. On March 3, the VNCHMF predicted that there would be 11–13 tropical cyclones over the South China Sea during the season, with 5-6 directly affecting Vietnam. Later that month the Hong Kong Observatory, predicted that the typhoon season in Hong Kong would be near normal with four to seven tropical cyclones passing within 500 km (310 mi) of the territory compared to an average of 6. In late April, the China Meteorological Administration's Shanghai Typhoon Institute (CMA-STI) predicted that between 22 and 25 tropical storms would develop within the basin during the year, while the Thai Meteorological Department (TMD) predicted that at least two tropical storms would move towards Thailand during 2013. The first of the two tropical storms was predicted to pass near Upper Thailand in either August or September, while the other one was expected to move to the south of Southern Thailand during October or November. On May 7, the TSR Consortium released their first forecast of the season and predicted that the basin would see a near average season with 25.6 tropical storms, 16 typhoons, 8.9 "intense" typhoons and an ACE index of about 311 units.
In late June after a slow start to the season Taiwan's Central Weather Bureau predicted that the season, would be near average of 25.7 with 23–27 tropical storms occurring over the basin during 2013. Between two and four of the systems were also predicted to affect Taiwan compared to an average of around 3.6. Within its July forecast update TSR noted that despite the slow start to the season, they continued to anticipate either near or slightly above-normal activity for the remainder of 2013; however, the ACE index was reduced slightly to 294 units. During July, PAGASA predicted that between eight and eleven tropical cyclones were likely to develop and/or enter the Philippine area of responsibility between July and September while five to eight were predicted to occur between October and December. Later in the month the VNCHMF, predicted that nine to ten tropical cyclones would be observed within the South China Sea, during the rest of the year. They also predicted that four to five tropical cyclones would directly affect Vietnam, while the CMA-STI predicted that between 22 and 25 tropical storms would develop or move into the basin during the year. On August 6, TSR released their August update and significantly lowered their forecast to 22.3 tropical storms, 13.2 typhoons, 6.6 "intense" typhoons and an ACE index of about 230, which they noted would result in activity about 20% below their 1965–2012 average. This was because the season was running about 60% below the expected year-to-date activity and only one to two typhoons had developed by the end of July. During October 2013, the VNCHMF predicted that one to two tropical cyclones would develop and possibly affect Vietnam between November 2013 and April 2014.
Season summary
The first two-thirds of the season were very weak, with only two typhoons forming despite the average amount of named storms forming. However, the season became dramatically active since mid-September. The last fourteen named storms formed within approximately two months, yet only three of them were below the typhoon strength. Initially, Typhoon Man-yi made landfall over Japan. Tropical Depression 18W, known in Vietnam as Tropical Storm No.8, flooding triggered by the storm in Vietnam, Laos and Thailand damaged nearly US$80 million and 23 deaths. Typhoon Usagi made landfall over Guangdong, China and cost US$4.6 billion in the country, which was the third strongest storm of the basin in 2013. Later, Typhoon Wutip made landfall over Vietnam. In early October, Typhoon Fitow made landfall over Fujian, China and caused over US$10 billion damage, becoming the costliest tropical cyclone in 2013. Typhoon Danas affected Japan and South Korea, but without significant damage.
Typhoon Nari brought significant damage over the Philippines and eventually made landfall over Vietnam, as well as Typhoon Wipha which killed 41 people in Japan. Typhoons Francisco and Lekima did not directly affect any country, but they were both violent typhoons, especially the latter one becoming the second strongest of this basin in 2013. Typhoon Krosa crossed northern Luzon on October 31 and intensified further, although it dissipated in the South China Sea. In early November, Tropical Depression Wilma formed over the Caroline Islands, moved out of the basin, and ultimately arrived in the Arabian Sea in mid-November.
At the same time in early November, Typhoon Haiyan initially affected Palau significantly. The typhoon later became one of the most intense tropical cyclones on record and immediately made landfall over the Philippines. After arriving at the South China Sea, Haiyan made landfall over Vietnam and also impact Guangxi and Hainan provinces of China. Typhoon Haiyan, also known as Typhoon Yolanda, caused 6,300 fatalities and over US$2 billion damage in the Philippines, becoming the deadliest and costliest typhoon in modern Philippine history.
Systems
Severe Tropical Storm Sonamu (Auring)
Early on January 1, a tropical depression developed about 1,090 km (675 mi) southwest of Guam. Over the next couple of days, the depression moved northwestward and gradually developed in an area of moderate windshear. Late on January 2, the center passed over the Philippine island of Mindanao but maintained its deep convective banding, which prompted the JTWC to issue a Tropical Cyclone Formation Alert (TCFA). During the next day, PAGASA named the depression Auring. The system moved westwards into the Sulu Sea, and the JTWC initiated advisories on the system as 01W. The JMA reported later that day that the depression intensified into Tropical Storm Sonamu, before the JTWC followed suit early on January 4 as the system continued to consolidate. After further strengthening, Sonamu intensified into a severe tropical storm on January 5, with 10-minute sustained winds of 95 km/h (60 mph). Early on January 8, the JMA and JTWC reported that Sonamu weakened into a tropical depression. The system dissipated on January 10 about 110 km (70 mi) west of Bintulu in Sarawak.
Within the Philippines, 1 person drowned while another person died after being hit by a coconut tree. A passenger ship was stranded near the coast of Dumaguete City on January 3 before being rescued.
The name Sonamu was retired and replaced by Jongdari which was first used in the 2018 season. The reason is that it's sound similar to tsunami, which trigger fear in Malaysia.
Tropical Depression Bising
Early on January 6, the JMA started to monitor a tropical depression that had developed, about 480 km (300 mi) to the southeast of Melekeok, Palau. Over the next few days the JMA continued to monitor the system as a tropical depression, before PAGASA named it Bising during January 11. Over the next few days the system moved towards the north-northeast, before it was last noted during January 13, as it weakened into an area of low pressure.
Bising caused moderate to heavy rains across Bicol Region, Eastern Visayas, Central Visayas and Mindanao. A school laboratory in Lanuza was damaged, and the loss were amounted to Php1.5 million (US$37,000).
Tropical Storm Shanshan (Crising)
On February 18, a tropical depression formed about 650 km (405 mi) east of southern Mindanao, with PAGASA naming it Crising. With low to moderate wind shear, the depression developed further. On February 19, the JTWC initiated warnings on Tropical Depression 02W, but discontinued advisories two days later after the circulation became poorly defined and convection was sheared. However, the JMA reported that the depression intensified into Tropical Storm Shanshan on February 21. The next day, Shanshan weakened into a tropical depression before dissipating east of Natuna Islands.
Heavy rains from the storm triggered flooding in the southern Philippines that killed eleven people and left two others missing. The storm damaged 1,346 houses, while crop damage estimated to be ₱11.2 million (US$275,000). On February 20, classes in three cities in Cebu were suspended due to heavy rains.
Tropical Storm Yagi (Dante)
On June 6, a tropical depression formed southeast of the Philippines within an area of moderate wind shear. Located along the western edge of the subtropical ridge, the system gradually intensified while moving to the northeast, aided by strong divergence. On June 7, PAGASA named the system Dante, and the next day the JMA upgraded the depression to Tropical Storm Yagi. Later, the JTWC initiated advisories and quickly upgraded to tropical storm status after the system consolidated. Slow strengthening continued, and Yagi peaked with winds of 85 km/h (55 mph) on June 10. However, the storm was soon impacted by northwesterly wind shear, causing the system to become disorganized and weaken in intensity. Early on June 12, Yagi became extratropical to the south of Japan, and four days later it dissipated about 1,600 km (995 mi) southeast of Tokyo, Japan.
After Yagi had enhanced the southwest monsoon which brought heavy rain to parts of the Philippines, PAGASA declared that the rainy season had begun on June 10, 2013. Yagi also brought some rain to parts of Japan, including the island of Honshu.
Tropical Storm Leepi (Emong)
Early on June 16, a tropical depression formed southeast of the Philippines, which PAGASA named Emong. Late on June 17, the JTWC initiated advisories on Tropical Depression 04W. The next day, the JMA upgraded the depression to Tropical Storm Leepi on June 18 after further organization and a general northward movement. Interaction with a tropical upper tropospheric trough (TUTT) cell to the east of Leepi sheared the convection to the southwest of the center, which consisted of several smaller circulations. Based on this occurrence, the JTWC downgraded the system to tropical depression intensity early on June 20, and early the next day, the JMA declared Leepi as extratropical near southwestern Japan. The storm fully dissipated early on June 24.
Due to heavy rainfall from the precursor system, PAGASA issued a flash flood warning for parts of Mindanao. Heavy precipitation was reported in Davao City, as well as Greater Manila, where the Metropolitan Manila Development Authority offered free rides to stricken commuters. This system caused rains over parts of the Philippines including Southern Luzon, Visayas and Northern Mindanao. Later, the outer rainbands of Leepi caused downpours over eastern Taiwan. In Okinawa, sustained winds reached 55 km/h (35 mph) and gusts peaked at 87 km/h (54 mph). Despite losing much of its convection before reaching Japan, the remnants of Leepi continued to drop heavy rainfall. In Umaji, Kōchi, a station recorded 354.5 mm (13.96 in) of rain in a 24-hour period, more than half of the average June rainfall for the station.