This is also the first tropical cyclone recognized by the Japan Meteorological Agency, but not Joint Typhoon Warning Center, since Changmi in 2002.

[1] The fortieth tropical cyclone and twenty-ninth named storm of the very active 2004 Pacific typhoon season, the origins of Merbok can be traced from a disturbance in the Philippine Sea early on November 22, with the PAGASA first issuing advisories as Tropical Depression Violeta, to the east of Baler, Aurora.

The storm soon made landfall on the night of the same day, while gradually weakening over the high terrains of Luzon.

The weakened system emerged off the northwest coast of the country before the last advisory was issued by the two agencies.

Throughout its passage, Merbok was blamed for 31 individuals killed and causing over ₱12.368 billion ($254 million) worth of damages across Luzon.