The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) in its 0500 hours bulletin of Tuesday (29 October) has stated that Leon was estimated to be 645 kilometres East of Tuguegarao City, Cagayan, moving West-Northwestward at 10 kilometres per hour. It has mmaximum sustained winds of 110 kilometres per hour near the center, and gustiness of up to 135 kilometres per hour.

It is forecast to move generally West-Northwestward and then turn northwestward on Wednesday (30 October), until it makes its predicted landfall along the Eastern coast of Taiwan on Thursday (31 October) afternoon or evening. After crossing the landmass of Taiwan, Leon will then turn to the Northward to North-Northeastward direction, towards the East China Sea and exit the Philippine Area of Responsibility (PAR) on Thursday (31 October) evening or early Friday morning (01 November). Leon is expected to rapidly intensify throughout its passage over the Philippine Sea and may reach typhoon category before 1700 hours of Tuesday (29 October). While landfall at Batanes is unlikely, there is an increasing chance that Leon will reach super typhoon category during its period of closest approach to Batanes. The following updates are available:

• Heavy Rainfall Outlook: Intense to torrential rainfall (over 200 mm) is expected over Batanes and Cagayan including Babuyan Islands on Tuesday (29 October), while heavy to intense rainfall (100-200 mm) is expected over Ilocos Norte, Apayao, Occidental Mindoro, and Antique. Moderate to heavy rainfall (50-100 mm) is also expected over Ilocos Sur, Isabela, Abra, Kalinga, Calamian Islands, Romblon, Negros Occidental, and Aklan.
• On Wednesday (30 October), Intense to torrential rainfall (over 200 mm) is expected over Batanes and Cagayan including Babuyan Islands on Tuesday (29 October), while heavy to intense rainfall (100-200 mm) is expected over Ilocos Norte, Apayao, Occidental Mindoro, Calamian Islands and Antique. Moderate to heavy rainfall (50-100 mm) is also expected over Ilocos Sur, Isabela, Abra, Bataan, Cavite, Batangas, Romblon, and Aklan.
• Severe Winds: Tropical Wind Signal-01 is currently active in Batanes, Cagayan including Babuyan Islands, Isabela, Quirino, Nueva Vizcaya, Apayao, Kalinga, Abra, Mountain Province, Ifugao, Benguet, Ilocos Norte, Ilocos Sur, La Union, Aurora, the northern portion of Quezon including Polillo Islands (General Nakar, Infanta, Real), Camarines Norte, the eastern portion of Camarines Sur (Tinambac, Siruma, Goa, Lagonoy, San Jose, Garchitorena, Caramoan, Presentacion, Tigaon, Calabanga, Saglay), Catanduanes, the eastern portion of Albay (Rapu-Rapu, Bacacay, City of Tabaco, Tiwi, Malilipot, Malinao, Santo Domingo, Manito), and the northeastern portion of Sorsogon (Prieto Diaz, City of Sorsogon, Gubat) in Visayas. In Luzon, it is active in the eastern portion of Northern Samar (San Roque, Pambujan, Catubig, Laoang, Palapag, Gamay, Lapinig, Mapanas, Mondragon) and the northern portion of Eastern Samar (Jipapad, Arteche, Oras, San Policarpo).
• Minimal to minor impacts from strong winds are possible within any of the areas under Tropical Wind Signal-01. The highest wind signal which may be hoisted during the occurrence of Leon is Wind Signal-03 or 04, especially in Extreme Northern Luzon. The hoisting of Wind Signal-05 is also not ruled out.
• Furthermore, the wind flow coming towards the circulation of Leon will also bring gusty conditions (strong to gale-force) over Bataan, Metro Manila, CALABARZON, MIMAROPA, Bicol Region, Visayas, Dinagat Islands, Surigao del Norte, and Camiguin on Tuesday (29 October). On Wednesday (30 October), gale-force winds are expected in Bataan, Metro Manila, CALABARZON, MIMAROPA, Bicol Region, most of Visayas, and Dinagat Islands.
• Sea conditions: Rough to very rough seas are expected in the seaboards of Batanes, Babuyan Islands, Isabela, mainland Cagayan, northern Aurora, Camarines Norte, Polillo Islands, Camarines Sur, Catanduanes, Northern Samar, and Eastern Samar. Sea travel is considered risky for all types of vessels in these areas, and mariners are advised to remain in port or seek shelter until conditions improve.