Chaba later reached the peak intensity of 1-minute sustained winds of 280 km/h (175 mph) and a central pressure of 911 hPa (26.90 inHg), equivalent to a Category-5 super typhoon.

[2] Despite a marginally favorable environment, the Japan Meteorological Agency (JMA) upgraded the system to a tropical storm and assigned it the name Chaba late the next day.

[5] By September 30, Chaba had intensified into a severe tropical storm after deep convection had evolved into a banding feature and very favorable conditions such as very low wind shear and sea surface temperatures (SSTs) of about 30 degrees Celsius.

[6][7] On October 1, Chaba entered the Philippine area of responsibility, with PAGASA assigning the local name Igme, as it started to move in a northwestward direction.

[9][10] During the next day, Chaba became more symmetric as feeder bands wrapped into its deep central convection, signalling the onset of explosive intensification.

[15] Later, significant weakening led the JTWC to downgrade Chaba further to a Category 2 typhoon, due to interaction with strong north-northeasterly winds.

[17] At that time, Chaba started to undergo extratropical transition and the JTWC issued its final advisory a few hours later, while downgrading the system to a tropical storm.