Typhoon Atsani's eye was "ringed" or surrounded by powerful thunderstorms on August 17 when NASA's Terra satellite passed overhead.
Typhoon Atsani formed on August 14 as Tropical Depression 17W. By 2100 UTC (5 p.m. EDT) that day, 17W strengthened into a tropical depression was named Atsani. On August 16 at 0900 UTC (5 a.m. EDT), Atsani strengthened into a typhoon.
On Aug. 17 at 7:20 a.m. EDT (11:20 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Terra satellite captured an infrared image of strong thunderstorms around Typhoon Atsani's eye. The infrared imagery revealed very cold thunderstorm cloud tops with temperatures as cold as or colder than -63F/-53C. Cloud top temperatures that high indicate strong storms with the potential to drop heavy rainfall.
At 1500 UTC (11 a.m. EDT), on August 17, Typhoon Atsani had maximum sustained winds near 95 knots (109.3 mph/ 175.9 kph). It was centered near 15.0 North latitude and 158.0 East longitude, about 358 nautical miles (412 miles/663 km) north-northwest of Ujelang. Atsani was moving to the north-northwest at 6 knots (6.9 mph/11.1 kph).
The Joint Typhoon Warning Center expects Atsani to move to the northwest and intensify up to 130 knots by August 20 before weakening again.