The 1986 Pacific typhoon season was an above average season, featuring 29 named storms, 19 typhoons, and 3 super typhoons. It has no official bounds; it ran year-round in 1986, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and December. These dates conventionally delimit the period of each year when most tropical cyclones form in the northwestern Pacific Ocean. Tropical Storms formed in the entire west pacific basin were assigned a name by the Joint Typhoon Warning Center. Tropical depressions that enter or form in the Philippine area of responsibility are assigned a name by the Philippine Atmospheric, Geophysical and Astronomical Services Administration or PAGASA. This can often result in the same storm having two names.
A total of 32 tropical depressions formed in 1986 in the Western Pacific over an eleven-month time span. Of the 32, 30 became tropical storms, 19 storms reached typhoon intensity, and 3 reached super typhoon strength. The Joint Typhoon Warning Center considered Vera as two tropical cyclones, when all the warning centers treated Vera as one in real time, while another, Georgette, originated in the Eastern Pacific. Six of the tropical cyclones formed in August, which was the busiest month of the season. Eight tropical cyclones moved through the Philippines this season. Most of the deaths attributed to typhoons in 1986 were caused by Peggy and Wayne.
Seasonal summary
Of the thirty tropical storms formed in 1986 in the Western Pacific (from 32 tropical depressions), 19 reached typhoon intensity, and three reached super typhoon strength. Broken down by month, one tropical cyclone formed in February, one in April, two in May, three in June, three in July, seven in August, three in September, four in October, six in November, and two forming in December. Vera was considered two tropical cyclones by the Joint Typhoon Warning Center after the fact, though it was operationally treated as one system, and Georgette, was a former Eastern Pacific cyclone. Eight tropical cyclones moved through the Philippines this season, while three struck mainland China, one struck Korea, and one crossed the Japanese coast. Peggy and Wayne accounted for a majority of the death toll this season. Tropical cyclones accounted for 35 percent of the annual rainfall in Hong Kong this year.
Systems
Typhoon Judy (Akang)
The initial disturbance formed within two degrees of the equator within the monsoon trough on January 25. Over succeeding days, the thunderstorm area increased in size. However, it decreased significantly on January 30. As the convective area moved slowly westward, it increased in coverage once more, organizing into a tropical depression on February 1. Moving on a parabolic course east of the Philippines, Judy gained tropical storm status on February 2, and typhoon strength on February 4 after recurving to the northwest of the subtropical ridge. As westerly winds increased aloft, vertical wind shear weakened Judy back into a tropical storm, which lost tropical characteristics on February 6. After drifting slightly more east-northeastward, the low-pressure area dissipated.
Typhoon Ken (Bising)
A tropical disturbance formed along the near equatorial trough on April 20 well to the south of Guam. The system slowly increased in organization, becoming a tropical depression on April 26. The system quickly developed thereafter, becoming a typhoon on April 27 while moving northward. The system reached its peak intensity on April 28. The subtropical ridge built to its northwest, steering Ken to the west. South-westerly vertical wind shear led to a weakening trend to begin on April 29. On April 30, Ken's low level circulation was exposed, no longer having any thunderstorms near the center. The remnant low drifted westward, dissipating by May 3. It was also formed after Chernobyl Disaster.
Typhoon Lola
Forming as a twin cyclone with South Pacific's Cyclone Namu, the initial disturbance of Lola developed within the monsoon trough south of Guam. Moving eastward, the system slowly developed becoming a tropical depression, then a tropical storm, on May 17. Lola moved over Pohnpei, becoming their most destructive cyclone since 1958. In light of the damage caused by the storm, the island was declared a major disaster area on June 3 by the American government. Continuing to intensify, Lola became a typhoon on May 18 and turned northwest. Rapid intensification continued, with Lola becoming a super typhoon on May 19. Peaking in intensity on May 20, Lola recurved to the north and northeast, weakening into a tropical storm on May 23 and evolving into an extratropical cyclone later that day.
Tropical Storm Mac (Klaring)
This system moved generally to the east-northeast throughout its life cycle. Forming near Hainan Island on May 21 as a monsoon depression, the initial tropical disturbance moved through the South China Sea while slowly organizing. Becoming a tropical depression in the Formosa Strait, Mac quickly became a tropical storm and turned northeast, paralleling the coast of Taiwan. On May 27, Mac turned back towards the east-northeast as upper level westerly winds increased, causing vertical wind shear which led to Mac weakening into a tropical depression before dissipating on May 29.
Typhoon Nancy (Deling)
A broad area of convection formed to the southeast of Pohnpei in mid June. The convection formed a tropical depression on June 21 to the east of the Philippines. Tropical Storm Nancy was named the next and quickly strengthened into a typhoon with max winds of 75 kn (139 km/h) before striking northeastern Taiwan. After departing the island Nancy weakened to tropical storm strength while moving north through the East China Sea. Nancy passed through the Korea Straits just before turning extratropical and accelerating northeastward into the Sea of Japan. Torrential rains fell throughout South Korea, as a result of flooding 12 people were killed and 22,477 acres (90.96 km2) of farmland were destroyed.
Tropical Storm Owen (Emang)
Forming as a tropical disturbance southwest of Kosrae on June 21. Moving west-northwest, the system gradually became better organized. On June 28, the disturbance had organized into a tropical depression. Recurving east of the Philippines and Taiwan, Owen developed into a tropical storm, reaching its maximum intensity on June 29. Thereafter, east-northeasterly winds aloft led to vertical wind shear which weakened Owen. While moving north-northeast towards southern Japan, the system devolved into a low level circulation devoid of thunderstorms, and dissipated on July 2.
Typhoon Peggy (Gading)
Peggy, which developed on July 3 east of the Philippines, steadily strengthened to reach a peak of 130 knots (240 km/h) super typhoon on July 7. As Peggy continued westward, it slowly weakened, and hit northeastern Luzon on July 9 as a 90 kn (170 km/h) typhoon. A slight weakening of the subtropical ridge brought Peggy more northward, where it hit southeastern China as a 55 kn (102 km/h) tropical storm on the July 11. In Hong Kong, winds gusted to 78 knots (144 km/h) at Tate's Cairn and rainfall totals reached 449 millimetres (17.7 in) at Tai Mo Shan. Peggy's fury resulted in 333 casualties and US$2.5 million (1986 dollars) in damage from torrential flooding.
Typhoon Roger (Heling)
An upper-level low retrograded westward across the tropical Pacific Ocean beginning on July 4. On July 8, a tropical disturbance formed southeast of the upper low southwest of Enewetak Atoll. The system moved westward, slowly organizing. Becoming a tropical depression on July 13, the small system turned northwest, recurving gradually around a subtropical ridge to its east and northeast. The system strengthened into a tropical storm later on July 13, and a typhoon on July 14 to the south of Japan. After turning to the northeast, the system began to experience northeasterly vertical wind shear and began to weaken. After passing east of Okinawa, the system began to transition into an extratropical cyclone, a process which completed on July 17 near the southern coast of Japan.
Tropical Storm Nine
Forming on the South China Sea on July 19, the cyclone moved northwest into mainland China on July 22, maintaining its circulation as it turned westward before dissipating on July 24. This system was recognized by the Japanese Meteorological Agency as a tropical storm.
Severe Tropical Storm Sarah (Iliang)
Developing in the Philippine Sea on July 30, the system developed as it moved westward, becoming a tropical storm on July 31. On August 1, its mid-level circulation center crossed into the South China Sea while its surface circulation was left behind east of the Philippines. Sarah's broad circulation center was difficult to locate until it began moving northeast east of Luzon on August 2, when it intensified to its peak intensity. As Sarah moved east of Honshu, it evolved into an extratropical cyclone. Fourteen died in Japan due to Sarah. Damages totaled to ¥105.5 billion (US$627 million).
Severe Tropical Storm Georgette
From August 3 to August 4, Tropical Storm Georgette existed in the Eastern Pacific, but degraded into a tropical wave while moving rapidly westward. Five days later in the Western Pacific, Georgette regenerated into a tropical storm, and became a typhoon on August 10. At this time, a tropical disturbance was developing to its west, and it became Tropical Storm Tip on the 11th. Tip and Georgette underwent fujiwhara interaction, causing smaller Georgette to loop as the larger storm Tip headed to the north. Georgette weakened to a tropical depression on August 15, and was absorbed by Tip's large inflow band on August 16.
CMA Tropical Storm Fifteen
This system formed in the South China Sea on August 9, and moved northwest through Hainan Island into mainland China, dissipating on August 12. In Hong Kong, winds gusted to 70 knots (130 km/h) at Tate's Cairn and Tai Mo Shan while Tai Po received 343 millimetres (13.5 in) of rainfall from the depression. Extensive flooding occurred on Hainan and western Guangdong Province, killing two people. The Hong Kong Royal Observatory considered this system a tropical depression.
Typhoon Tip
Georgette became a typhoon on August 10 to the east of a tropical disturbance, which developed into Tropical Storm Tip on August 11. Tip and Georgette underwent the Fujiwhara effect, causing smaller Georgette to loop as the larger storm Tip headed to the north. Georgette became absorbed by Tip's large inflow band on August 16. Tip strengthened to a typhoon, and reached a peak intensity of 80 kn (150 km/h) winds before vertical wind shear caused the system to weaken. On August 19, Tip became extratropical, but the system persisted as a remnant extratropical low for six more days.
Typhoon Vera (Loleng)
The most intense and extensive monsoon trough since 1974 spawned a tropical depression on August 15. It drifted to the southeast, relocating several times in its formative stages. On August 16 it was upgraded to Tropical Storm Vera, and operationally the storm was to continue eastward, continuing to relocate in the broad monsoon trough and becoming a storm again on August 17 after weakening. Post-analysis by the Joint Typhoon Warning Center suggested that the first storm turned to the west and dissipated, and that a new, separate storm formed well to the east on August 17. However, the Japan Meteorological Agency maintained the system as a single storm.
Vera drifted northward until an upper-level ridge forced the storm to the east, providing upper-level outflow for Vera to strengthen to a typhoon on August 20. On August 22, Vera attained winds of 165 km/h (105 mph) before the weakening ridge forced the typhoon to the west, retracing its path it took days before. The typhoon slowly weakened, and hit Okinawa on August 25 as a 155 km/h (95 mph) typhoon. Vera turned to the northeast, hit South Korea on August 28 as a minimal typhoon, and became extratropical on August 29 in the Sea of Japan. A total of 23 people were killed from the storm, with moderate to heavy damage in its path as far north as the Soviet Far East. Damage totalled US$22 million (1986 dollars) across South Korea.
Typhoon Wayne (Miding)
One of the longest lasting Western Pacific system on record began its long life on August 16 in the South China Sea, having formed from the monsoon trough. It drifted to the southwest, then looped back to the northwest, becoming a tropical storm on August 18. Wayne turned to the northeast and became a typhoon on August 19. In Hong Kong, winds gusted to 78 knots (144 km/h) at Tate's Cairn. The typhoon passed offshore of southeastern China and hit western Taiwan on August 22. Wayne turned back to the south and southwest. Vertical shear caused Wayne to weaken to a depression on August 25. Wayne turned back to the northeast, rotating around Vera. Once Vera accelerated away, Wayne drifted northeastward through the South China Sea, becoming a tropical storm on August 27.