A mid-latitude cyclone weakened a subtropical ridge to its north, allowing the disturbance to slowly gain latitude, and on October 3, the system organized into a tropical depression.

The Joint Typhoon Warning Center (JTWC) started monitoring the system at 06:00 UTC on October 1 while it was located northwest of Guam.

A mid-latitude trough weakened a subtropical ridge to its north, allowing the tropical disturbance to slowly gain latitude.

Following a surge in the monsoon trough, a Tropical Cyclone Formation Alert was issued at 08:00 UTC on October 3.

[1] At the same time, the Japan Meteorological Agency (JMA) classified the system as a tropical depression,[2][nb 3] with the JTWC doing the same at 00:00 UTC on October 4.

[nb 4] Post-storm analysis from the JTWC indicated, however, that the depression had attained tropical storm midday on October 3.

[5] At around this time, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) also monitored the storm and assigned it with the local name Sendang.

[5] Continuing to intensify, Typhoon Orchid tracked due westward south of subtropical ridge.

[7] Increased convergence in the southern quadrant enhanced convection, and dual outflow channels aloft were present.

Over a 42-hour period from October 10–12, Orchid took a "stair-stepped" track - moving to the north then back to the northeast due to interaction with Typhoon Pat.

At 00:00 UTC on October 13, the final warning was issued by the JTWC since Orchid had transitioned into an extratropical cyclone,[1] though according to the JMA, this process did not occur until 24 hours later.

[5] Although Typhoon Orchid spent much of its life over the open ocean, away from land, high surf, in conjunction with Pat, killed two people on Guam on October 17.

In addition, its slow movement south of Japan resulted in prolonged rains to much of the island nation.

[13] Offshore Honshu, rough seas sunk the vessel Panama flag, although everyone there was rescued safely and only one person was wounded.

[18] Shin-Kodaira Station was submerged underwater due to landslides, flooding 500 m (1,600 ft) of train tracks.