Typhoon Rosal weakened slightly Saturday morning as it moved over waters east of Taiwan, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said.

As of 5 a.m., Rosal was located 420 kilometers (261 miles) north of Itbayat, Batanes, with maximum sustained winds of 150 kph (93 mph) near its center and gusts of up to 185 kph (115 mph).

The typhoon was reportedly moving southwest at 10 kph (6 mph).

Meanwhile, Tropical Cyclone Wind Signal No. 1 remained in effect over Batanes.

PAGASA said Rosal was expected to leave the Philippine Area of Responsibility on Saturday morning before moving toward the East China Sea.

The storm is also forecasted to continue weakening as it approaches the area and could be downgraded to a severe tropical storm by Sunday.