The 1986 Pacific typhoon season 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.
Super 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)