Spiraling bands of Typhoon Sinlaku can clearly be seen to the west of Taiwan on Thursday.
Typhoon Sinlaku first attained storm force to the east of the Philippines over the weekend, before strengthening on a gradual northward course.
Taiwan was on alert late in the week for heavy rainfall and gusty winds brought in by the Category 4 storm's outer bands.
Sinlaku's maximum sustained winds early Friday were estimated to be near 150 mph (240 km/h) as the storm moved northwestward toward Japan's southernmost islands to the east of Taiwan.
Sinlaku was predicted to weaken to minimal typhoon strength next week as it approached the southern coast of Japan's Kyushu Island.
Typhoon Sinlaku Track
Satellite Loop: University of Wisconsin