[2][3] However the Joint Typhoon Warning Center (JTWC) did not issue a Tropical Cyclone Formation Alert until later that day.

[1][9] Later that day after reaching the Philippine Sea, Halong started to strengthen and intensify into a severe tropical storm.

The JMA then reported that it had completed its extratropical transition and issued their final advisory on the remnant low of Halong.

At 1500 UTC that day Signal Number One was initially issued over northern Palawan, Occidental Mindoro and Lubang Island.

[10] At its maximum coverage (at 0930 UTC May 17), Storm Signal Number 3 was issued for Zambales, Pangasinan, La Union, Tarlac, Benguet and Ilocos Sur, Signal Number 2 was for Bataan, Bulacan, Pampanga, Nueva Vizcaya, Nueva Ecija, Quirino, Ifugao, Mt.

Province, Kalinga, Abra, Apayao and Ilocos Norte and Signal Number 1 was raised for Lubang Island, Batangas, Cavite, Laguna, Rizal, northern Quezon, Isabela, Aurora, Cagayan, Calayan Island, Babuyan Group of Islands, Batanes and Metro Manila[11] Further on as Cosme (Halong) razed through Northern Luzon, these storm signals were scaled back until the storm reached the Cagayan-Batanes area and the Pacific Ocean proper.

[14] The Subic-Olongapo area, one of the economic zones of the Philippines, experienced power outages as the storm got closer to Zambales on May 17.

[19] Because the damage caused by the storm in Zambales is extensive even in infrastructure, repair was forced to be done on schools there as that time, classes are to resume in the next few weeks.

[25] The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) assigned the name Cosme to the tropical storm.