When NASA's Aqua satellite passed over the Northwestern Pacific Ocean on July 19, the large Tropical Storm Ampil appeared much more organized than it did the previous day.
On July 19 at 12:55 a.m. EDT (0455 UTC), the MODIS or Moderate Resolution Imaging Spectroradiometer instrument aboard NASA's Aqua satellite captured a visible light image of the storm. Ampil took on the shape of a more organized tropical storm, although it was still elongated. According to the Joint Typhoon Warning Center, the elongation was about 100 nautical miles in diameter from southwest to northeast.
MODIS imagery revealed powerful thunderstorms surrounded the center of circulation and a large feeder band of thunderstorms extended from the eastern quadrant to the south. Satellite imagery shows that Ampil is about 500 miles in diameter.
The Joint Typhoon Warning Center or JTWC noted at 5 a.m. EDT (0900 UTC) on July 18 that Ampil's maximum sustained winds were near 40 knots (46 mph/74 kph). Ampil was centered near 20.9 degrees north latitude and 131.1 degrees east longitude, approximately 398 nautical miles south-southeast of Kadena Air Base.
JTWC expects Ampil to curve to the northwest and intensify. It is forecast to pass near Kadena Air Base, Okinawa Island, Japan on July 20 en route to a final landfall in mainland China by July 22.