After undergoing serious consolidating with convective banding, the low pressure area was upgraded to a Joint Typhoon Warning Center late the same data.

Undergoing rapid deepening on September 26–27, the storm, now a Super Typhoon entered the Philippine Area of Responsibility, and was named Ofel.

Jangmi killed 2 people and caused about $77.8 million (2008 USD) in damage in Taiwan, as well as the typhoon also made operations of Maokong Gondola suspended due to erosion around a pillar, until March 30, 2010.

Owing to the low-level circulation center (LLCC) rapidly consolidating with convective banding, JTWC upgraded it to a tropical depression late on the same day.

At noon, the Japan Meteorological Agency (JMA) upgraded the system to a tropical storm and named it Jangmi, when it was tracking northwestward under the steering influence of the subtropical ridge in the northeast.

At 12Z, Jangmi attained peak intensity by the ten-minute maximum sustained winds reaching 115 knots (215 km/h, 130 mph) and the atmospheric pressure decreasing to 905 hPa (26.7 inHg).

In terms of ten-minute maximum sustained winds, it became the most intense tropical cyclone in the Northwest Pacific Ocean since Angela in 1995, tied with Nida in the next year, until Megi surpassed all of them in 2010.

After JTWC downgraded Jangmi to a typhoon, it made landfall over Nan'ao in Yilan, Taiwan at 15:40 TST (07:40 UTC) with ten-minute maximum sustained winds of 100 knots (185 km/h, 115 mph) and an atmospheric pressure of 925 hPa (27.3 inHg).

As JMA downgraded Jangmi to a tropical storm at noon, the system started to track northeastward along the weakened western finger of the subtropical ridge.

[13] Jangmi underwent extratropical transition while accelerating east-northeastward and then eastward on September 30, as well as upper-level westerly winds sheared the remaining convection to the east and south of the low-level circulation center with frontal features.

[14] JMA reported that Jangmi became an extratropical cyclone near the Ōsumi Islands early on October 1, and the system kept moving eastward rapidly during that day.

Considering local residents’ worries, On October 1, the Taipei City Government announced that the Maokong Gondola would temporarily suspend service and carry out further assessment; based on the suggestions made by construction, environment protection, and geological associations, it was decided that Tower No.

[3] The New Construction Office of Taipei City Government completed the work of moving T16 tower base and re-hanging cable on January 31, 2010.