Typhoon Ampil moved quickly away from Japan on Saturday.  At 5:00 p.m. EDT on Saturday the center of Typhoon Ampil was located at latitude 39.1°N and longitude 151.1°E which put the center about 620 miles (1000 km) east-northeast of Tokyo, Japan.  Ampil was moving toward the east-northeast at 24 m.p.h. (39 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 973 mb.

Typhoon Ampil weakened steadily as it moved quickly away from Japan on Saturday.  Ampil moved over water where the Sea Surface Temperatures were cooler.  In addition, the upper level westerly winds in the middle latitudes caused strong vertical wind shear.  The cooler water and wind shear caused Typhoon Ampil to weaken.  The circulation around the western side of Ampil’s circulation also pulled drier air into the southern and western parts of the typhoon.

Cooler water, strong vertical wind shear, and drier air affected the structure of Typhoon Ampil.  A large circular eye was still present at the center of Ampil’s circulation.  The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Thunderstorms were still occurring in bands in the eastern and northern parts of Typhoon Ampil.  Bands in the southern and western parts of Ampil’s circulation consisted primarily of showers and lower clouds.

There was still a large circulation around Typhoon Ampil.  Winds to typhoon force extended out 25 miles (40 km) from the center of Ampil’s circulation.  Winds to tropical storm force extended out 165 miles (265 km) from the center of Typhoon Ampil.

Typhoon Ampil will move through an environment that will be unfavorable for intensification during the next 24 hours.  Ampil will move over water where the Sea Surface Temperatures are near 23°C.  It will move under the upper level westerly winds in the middle latitudes. Those westerly winds will cause strong vertical wind shear.  The cooler water and strong vertical wind shear will cause Typhoon Ampil to continue to weaken during the next 24 hours.  The cooler water and strong wind shear will also cause Ampil to make a transition to a strong extratropical cyclone during the next 48 hours.

The westerly winds in the middle latitudes will steer Typhoon Ampil toward the east-northeast during the next 24 hours.  On its anticipated track, Typhoon Ampil will move farther away from Japan.