While experiencing favorable environmental conditions such as very warm sea surface temperatures and low wind shear, Nesat strengthened into a typhoon and reached its peak intensity on July 28.

A tropical disturbance accompanied by a broad low-pressure area formed near Palau on July 21; its circulation and associated convection remained elongated and disorganized for the next few days.

[4] Despite having a partially exposed LLCC, the JTWC also upgraded the system to a tropical depression early on July 26, after scatterometer data and the Dvorak technique revealed sufficient organization.

[5] Soon after that, the JMA upgraded the system to a tropical storm and assigned it the international name Nesat while it was located about 600 km (375 mi) east-northeast to Naga, Philippines.

[7] Tropical Storm Nesat began to intensify slowly as it tracked generally northwestward along the western edge of an extension of the subtropical ridge centered to the east, aided by a weak anticyclone over the system and a vigorous equatorward outflow channel.

[8][9] Amid favorable conditions with weakening vertical wind shear and sea surface temperatures of over 31 °C (88 °F) in the area southeast of Taiwan, Nesat intensified into a typhoon at around 06:00 UTC on July 28.

[20] On July 27, Executive Secretary Salvador Medialdea announces the suspension of work in all government offices and classes in public school at all levels in Metro Manila due to inclement weather.