The 1987 Pacific typhoon season was a below average season, though it featured a relatively high amount of typhoons. It had no official bounds; it ran year-round in 1987, but most tropical cyclones formed between June and November.Gary Padgett. May 2003 Tropical Cyclone Summary. Retrieved 2006-08-26. Tropical storms that formed in the entire 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 25 tropical cyclones formed this year in the Western Pacific, of which 24 became tropical storms. Of the 24, 17 storms reached typhoon intensity, of which 6 reached super typhoon strength.

Seasonal summary

A total of 25 tropical cyclones formed this year in the Western Pacific, of which 24 became tropical storms. Of the 24, 17 storms reached typhoon intensity, of which 6 reached super typhoon strength.

Systems Typhoon Orchid (Auring)

On January 3, a small and persistent area of thunderstorms near the International Date Line was first detected. During the next few days, it slowly increased in organization and thunderstorm activity after which a small and ragged central dense overcast formed and upper-level outflow improved. A Tropical Cyclone Formation Alert (TCFA) was issued late on January 7 for the disturbance. The JTWC then issued their first warning on Tropical Depression 01W during the afternoon of January 7. The next morning, on January 8, an aircraft reconnaissance mission reported tropical storm–winds and the depression was upgraded to a tropical storm and named Orchid. Orchid continued to gradually strengthen until it reached its peak intensity of on January 11 as a small typhoon. After reaching peak intensity, Orchid weakened rather quickly and by January 14, it had degenerated into an area of low pressure.

Orchid caused "extensive damage" on Ulithi Atoll but no deaths were reported. In the wake of the typhoon, the United States Federal Emergency Management Agency declared parts of the Federated States of Micronesia as a disaster area.

Tropical Storm Percy

During the first week of April, the typical northeasterly trades clashed with a Southern Hemisphere Westerly wind burst, creating an area of low pressure near the Caroline Islands. Gradual development occurred as it tracked westward, and on April 9, the JMA upgraded the system into a tropical depression, although the JTWC did not follow suit until April 11. Following data from a hurricane hunter aircraft that indicated that the depression was much stronger than expected, both the JTWC and JMA upgraded the depression later on April 11, with the latter estimating a peak wind speed of . Almost immediately thereafter, Percy weakened rapidly, with the storm's center becoming exposed from the deep convection. The JMA downgraded Percy into a tropical depression at 18:00 on April 11. Thirty hours later, the JTWC discontinued warnings. The JMA ceased tracking the storm while it was located near the northern tip of Luzon on April 16.

Tropical Storm Ruth

According to the JMA, a tropical depression developed on June 17 around southeast of Hong Kong, becoming the first tropical cyclone of the season to develop in the South China Sea. Its convective structure gradually improved as the depression tracked west-northwest under the influence of a ridge to its north, and at 00:00 UTC on June 18, the JTWC classified the system as a tropical depression. The JMA upgraded the depression into a tropical storm six hours later, while also estimating a peak wind speed of . The JTWC did not follow suit until at 18:00 UTC on June 18, when satellite estimated supported tropical storm intensity. Early on June 19, both the JTWC and JMA downgraded Ruth into a depression while it interacted with the southern China coast. Ruth dissipated inland later that day.

According to media outlets, Ruth inflicted widespread damage and casualties in southwest Guangdong and southeast Guangxi. In Guangdong, about of farmland were inundated and of banana plantations were damaged or destroyed. Extensive irrigation works were also damaged and 17 cows were killed. There, seven people were dead and eighty-six others were injured. Over 45,000 houses collapsed while more than 210,000 dwellings were damaged. Approximately 350 bridges were destroyed. In Guangxi, three deaths and twenty-six injuries were reported. As a result of the heavy rain, 45 bridges and over 780 houses sustained damaged. In addition, over of farmland were flooded. The railway service was also temporarily disrupted. In Hong Kong, damage was minimal and only one structure was demolished.

Typhoon Sperry (Bebeng)

The origins of Typhoon Sperry can be traced back to a weak surface circulation that formed on June 24 as part of the monsoon trough northwest of Truk. A second area of disturbed weather subsequently developed east of the Marshall Islands. The two areas consolidated into one on June 25, even though further development was initially slow to occur due to strong wind shear created by a tropical upper tropospheric trough near Wake Island. On June 25, the storm began to show signs of organization while tracking northwest; however, the JMA did not upgrade the system into a tropical depression until 00:00 UTC on June 26. On the next day, both the JTWC and JMA classified the system as Tropical Storm Sperry after the low-level center became better defined and the storm developed a central dense overcast – a large mass of deep convection. Later on June 28, Sperry was upgraded into a severe tropical storm by the JMA. On the next day, both agencies upgraded Sperry into a typhoon, the second of the season, based on reports from hurricane hunters. At noon on June 28, the JTWC and JMA reported that Sperry peaked in strength; the agencies estimated winds of respectively at this time. By June 29, Sperry began to approach a break in the ridge as well as a cold front, causing the storm to recurve to the northeast, becoming the first storm of the season to interact with mid-latitude westerlies. Thunderstorm activity quickly became displaced from the center due to increased wind shear, and the JMA downgraded Sperry into a severe tropical storm at 00:00 UTC on June 30. On the next day, both the JTWC and JMA declared Sperry an extratropical cyclone, although its remains later merged with a frontal zone.

Typhoon Thelma (Katring)

Thelma was first designated by the JMA as a tropical depression on July 7. After moving north, Thelma turned west, while remaining poorly organized. It finally attained typhoon status on July 9, soon after developing an eye, and began to intensify at a brisker clip, and on July 10, the JTWC upgraded Thelma into the first super typhoon of the season. During the evening of July 10, Thelma attained maximum intensity while well to the east of the Philippines. It also turned sharply northward in response to a trough while also slowly weakening. On July 15, Typhoon Thelma, now greatly reduced in intensity, struck the south coast of South Korea. The next day, Thelma rapidly dissipated, shortly after emerging into the Sea of Japan. 138 people were killed by Thelma.

Severe Tropical Storm Vernon (Diding)

On July 14, an area of disturbed weather formed while embedded in the near-equatorial monsoon trough in the eastern Caroline Islands. A well-defined low level circulation quickly developed, but convective activity remained limited until July 16, when both the JTWC and JMA upgraded the system into a tropical depression. Initially, the depression moved westwards towards the central Philippines while remaining disorganized. The JMA upgraded Vernon into a tropical storm at noon on July 18, and a severe tropical storm 12 hours later. At midday on July 1, the JTWC upgraded Vernon into a typhoon. Vernon began to track northwestward in the general direction of Taiwan. On July 20, the JMA estimated that Vernon reached its peak intensity, with winds of . Shortly after its peak, Typhoon Vernon began to interact with the rugged terrain of Taiwan as it skirted the eastern shore and the JTWC and JMA estimated that Vera rapidly weakened to a tropical depression on July 21. Vernon dissipated in the East China Sea on July 22 after passing the northern tip of Taiwan.

Typhoon Wynne (Gening)

The initial disturbance that would become Typhoon Wynne formed east of the International Date Line on July 20. Embedded in an environment of moderate wind shear, the disturbance slowly became more organized while tracking west. On July 21, the JMA classified the system as a tropical depression. Both the JTWC and JMA upgraded the depression into Tropical Storm Wynne at 06:00 UTC on July 22. After Wynne developed a central dense overcast, a large mass of deep convection, the JMA upgraded Wynne to a severe tropical storm midday on July 23. Later that day, the JTWC upgraded Wynne into a typhoon while the typhoon passed over the northern Marianas island of Alamagan. On the next day, after the storm developed an eye, the JMA followed suit and classified Wynne as a typhoon. A smaller than average typhoon, Wynne turned west-northwest. By July 26, Wynne reached its maximum intensity, with the JTWC reporting winds of and the JMA reporting winds of . of . As it rounded the western periphery of the subtropical ridge, the cyclone became sheared from the north, which caused the storm to weaken and its center to become exposed from the deep convection. Even so, it maintained typhoon intensity until July 30, according to both agencies. Recurving east of Honshū, Wynne continued to weaken. Both the JTWC and JMA determined that Wynne transitioned into an extratropical cyclone by the afternoon of July 31, although the JMA continued to track Wynne for five additional days.

Prior to the arrival of the typhoon on Alamagan, a handful of people sought shelter. All coconut trees and 90–100% of crops on islands of Alamagan and Agrihan were destroyed by the typhoon. All structures on Alamgan were destroyed, including the radio tower, which was the island's communication to the rest of Saipan. However, there were no serious injuries or deaths.

Typhoon Alex (Etang)

A tropical disturbance formed from a monsoon trough across the Caroline Islands on July 21. The system organized and convection increased rapidly, thus the JTWC named the storm Alex on the 23rd. Although initial models predicted Alex was to track through the Philippines, JTWC forecasters believed that Alex would track northward. On August 25, Alex reached peak intensity of 75 mph (120 km/h). It remained as that intensity for a full day before slowly weakening while trekking towards the Luzon Straight. The low-level southerly flow east of a frontal boundary across eastern China caused Alex to brush the Taiwanese coast. 1 person was reported dead in Taiwan. Once passing Taiwan, Alex tracked slightly westward and made landfall over Wenzhou, Zhejiang on the 27th. 125 deaths was reported in East China. The remnants of Alex aided a rainband over the Korean Peninsula that dumped over 12 inches (300 mm) of rain within 24-hours. The remnants of Alex dissipated on the 30th.

Typhoon Betty (Herming)