Merbok caused tropical storm-force winds in Hong Kong, as the center of the storm passed nearby.

The system was in a marginal environment for development, with satellite imagery showing scattered convection around a poorly organized circulation.

[3] At 15:00 UTC, the JTWC issued a Tropical Cyclone Formation Alert on the system as it was located approximately 185 nautical miles (345 km; 215 mi) west-northwest of Manila.

[4] On June 11 at 03:00 UTC, the JTWC issued its first warning on Tropical Depression 04W as it continued to organize, with cloud tops in the central dense overcast deepening.

[9] At the same time, Merbok peaked in intensity, with 10-min winds of 55 knots (100 km/h; 65 mph) and a minimum central pressure of 985 hPa (mbar; 29.09 inHg).

A retaining wall along Tai Tam Road in Stanley collapsed due to the heavy rainfall produced by Merbok.

[17] Across Guangdong Province, 32 homes were destroyed, 122,000 people reported property damage, 13,000 hectares of crops flooded, and roughly 155,000 households lost electricity.