Forming out of a tropical depression on September 16, Yagi quickly strengthened as it executed a slow clockwise loop over the open waters of the western Pacific Ocean.

The typhoon gradually weakened as it recurved towards the northeast and was downgraded to a severe tropical storm on September 24 and became extratropical the next day.

The typhoon caused severe damage on the island of Chichijima but no injuries were reported as a result of the storm.

On September 16, the Japan Meteorological Agency (JMA) began monitoring an area of convection as a tropical depression[1] about 1,270 km (790 mi) east-northeast of Guam.

Flaring convection was noted along the eastern portion of the developing system before the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert later that day.

Several hours after the JTWC issued their first advisory, the JMA upgraded the system to a tropical storm and gave it the name Yagi;[1] the name was contributed by Japan, and is the Japanese word for "goat".

[3][5] On September 22, Yagi passed by the islands of Iwo Jima and Chichijima as the storm recurved towards the northeast.