Bualoi rapidly intensified and became a typhoon on October 20, before its rate of strengthening was stopped by a tropical upper tropospheric trough the following day.

After affecting the Mariana Islands, where an emergency declaration was issued, warm moist air flowed into Bualoi, causing the atmosphere to become unstable and produce torrential rains over Japan on October 25.

Across the prefectures, about half of the 13 fatalities took place in a car as the automobiles were swept or submerged in rivers flooded by the rain, and happened during evacuation.

A low-pressure area located just north of Namonuito Atoll persisted on October 16, and generally tracked westward.

[1] The area was later reported to have developed into a tropical depression on October 18, according to the Japan Meteorological Agency (JMA).

[2] Later that day, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert on the system, designating it Invest 97W, after it was situated under low vertical wind shear and warm sea surface temperatures, being favorable conditions for further development, as flaring atmospheric convection obscured the low-level circulation center (LLCC) of the system.

[4] In addition, the depression further strengthened to a tropical storm while forming a central dense overcast (CDO),[5] receiving the name Bualoi from the JMA.

[8] While steering northwestward from a subtropical ridge, Bualoi intensified to a typhoon after further consolidation with improved deep banding.

[9] However, a tropical upper tropospheric trough (TUTT) cell to the northwest subdued outflow, stopping the rate of strengthening, which by that point the storm had 1-minute sustained winds of 140 km/h (85 mph).

[10] Bualoi later recommenced its development and rapidly intensified on October 21 while passing north of Saipan after sea temperatures remained favorable, despite the storm converging with the TUTT cell.

[13] On October 23, its eye became cloud-filled, and despite good environmental conditions, Bualoi began gradually weakening as it tracked northeastward.

[17] The convection was later displaced slightly northeast of the obscured LLCC on October 25, before being sheared, leading to Bualoi transitioning to an extratropical cyclone.

[20] Northern Mariana Islands Lieutenant Governor Arnold Palacios placed the territory under Typhoon Condition 3 on October 19.

[25] As Bualoi neared its passage through the Mariana Islands, flash flood alerts and heavy rain warnings were put in effect.