It was seen 470 kilometers east northeast of Borongan, Eastern Samar, with maximum winds of 120 kilometers per hour near the center, and gustiness of up to 150 kph, the Philippine Atmospheric Geophysical and Astronomical Services Administration said in its latest advisory.
It is forecast to be 590 kilometers east southeast of Casiguran, Aurora by Sunday morning.
Typhoon Butchoy continued to move north-northwest 15 kilometers per hour, with estimated rainfall of 15-25-mm per hour (heavy) within the 500-km diameter of the typhoon, it also said.
It is expected to enhance the southwest monsoon that will bring rains over Luzon and Visayas especially over the western section which may trigger flashfloods and landslides, Pagasa said.
Fishing boats and other small seacraft are advised not to venture out into the seaboards of Luzon, Visayas and Eastern Mindanao due to the big waves spawned by Butchoy and the southwest monsoon.