The storm subsequently entered a period of rapid intensification, commencing with Warren reaching its highest intensity on July 16.

An increase in organization and improved upper-level outflow promoted the JTWC to raise its development chances.

A Tropical Cyclone Formation Alert was issued for the system, which was located around 330 km (205 mi) southeast of Guam, at 05:30 UTC on July 12.

[6] At 00:00 UTC on July 14, the JMA declared the system a tropical storm,[6] with the JTWC upgrading Warren to a typhoon that evening.

[3] Around this time, the storm entered a rapid intensification phase, with the JTWC estimating that Warren reached its peak intensity of 210 km/h (130 mph), equal to a low-end Category 4 hurricane on the Saffir-Simpson scale, on July 16.

[2] Around the same time, the JMA estimated that Warren achieved its peak intensity of 105 mph (170 km/h) and a minimum barometric pressure of 940 mbar (28 inHg).

Forecasters at the JTWC continued to predict a westward motion because satellite imagery and mid-level synoptic analysis showed a subtropical ridge to its north.

[6] After entering the South China Sea,[7] Warren made landfall near the city of Shantou on the morning of July 19.

[7] The inner core of the typhoon brushed the northern Philippines, prompting flooding that resulted in the suspension of classes.

[8] Somewhere in the northern portion of the country, a man was killed when his motorcycle skidded on a slippery road as he went to inspect storm damage.

[9] A total of 3,560 homes were damaged and an additional 21,329 were destroyed, which resulted in 102,169 people or 19,224 families that either sought shelter or were homeless.

In addition, 270 ha (670 acres) of agricultural land were also flooded, resulting in the drownings of 1,370 pigs and 133,000 poultry.

Along the Tuen Mun Highway, a 15 m (50 ft) tree collapsed, damaging a van and injuring two men.

Seventeen flights were called off at the airport and ferry services to Tap Mun, Macau, and mainland China were suspended.

Throughout Hong Kong, 12 people were injured and a 5-year-old boy was reported missing after falling into the sea at a local park.