The disturbance, initially designated as 93W, was eventually upgraded the following day to a tropical depression by the Joint Typhoon Warning Center (JTWC) and re-designated as 26W.

The next day, the PAGASA and the JTWC upgraded Nalgae to a severe tropical storm status on October 28.

Upon its exit from Philippine jurisdiction, Nalgae then intensified into a Category 1-equivalent typhoon on JTWC; however, the JMA maintained its severe tropical storm classification for the system.

[1] The Japan Meteorological Agency (JMA) and the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), however, went further and already classified the disturbance as a tropical depression, with the latter assigning the name Paeng to the system.

It then traversed the Bicol Region and emerged into Ragay Gulf, eventually making landfall in Buenavista, Quezon; the storm maintained its strength during this period.

[7] Defying initial forecasts, Nalgae then moved southwestward and struck Mogpog on the island province of Marinduque.

Upon its exit from Philippine jurisdiction, Nalgae then intensified into a Category 1-equivalent typhoon on JTWC; however, the JMA maintained its severe tropical storm classification for the system.

Due to Nalgae's threat, PAGASA issued Signal 1 warnings for the Bicol Region and Eastern Visayas.

At least 45 people died due to flooding and landslides in Mindanao, all of which occurring a day before the storm made its landfalls.

[12] Initially, 72 people were reported to have died, but the death toll was revised by the National Disaster Risk Reduction and Management Council (NDRRMC) because of erroneous counting on the part of local officials;[12][13] however, the death toll would increase to 112 by November 1 as more bodies were recovered.

[16][17] The storm also delayed the removal of the wreckage of Korean Air Flight 631 after it overran the runway at Mactan–Cebu International Airport.

[6] The Philippine Institute of Volcanology and Seismology (PHIVOLCS) later warned of lahar from Mayon Volcano in Bicol during the tropical storm.

[26] The storm came while the city was hosting a financial meeting of senior Wall Street executives; however, despite the said warning and impending impact, the event's organizers announced that it would continue as planned.

[32] On the island of Mindanao, at least 68 people died[33][34] due to continuous flooding and landslides that were partially caused by Nalgae.

The entire region of Western Visayas was set up to the highest emergency response level due to increasing floods, which has already caused 4 casualties in the province of Aklan.

[43] Due to the high death toll, Philippine President Bongbong Marcos criticized local authorities for not forcing residents to immediately evacuate following Nalgae's hit in the country.