NASA's Aqua satellite scans powerful Typhoon Nepartak

NASA's Aqua satellite passed over Typhoon Nepartak after it became a major typhoon in the Northwestern Pacific Ocean.

The second tropical cyclone of the northwestern Pacific Ocean season formed on July 3 and strengthened quickly into a tropical storm that was named Nepartak.

On July 5 at 0359 UTC (11:59 p.m. EDT) infrared data from the Atmospheric Infrared Sounder aboard NASA's Aqua satellite detected strong thunderstorms completely surrounding the center of Nepartak with temperatures colder than minus 63 degrees Celsius (minus 81 Fahrenheit). Temperatures that cold indicate very powerful thunderstorms with cloud tops high into the troposphere. Bands of powerful thunderstorms wrapped into the low-level center of circulation from the northwest and southeast.

On July 5 at 1500 UTC (11 a.m. EDT) Nepartak's maximum sustained winds were near 120 knots (138 mph/222 kph). Nepartak is currently a category 4 hurricane on the Saffir-Simpson Scale, making it a major hurricane/typhoon. It was centered near 17.6 degrees north latitude and 132.7 degrees east longitude, about 821 nautical miles east-southeast of Taipei, Taiwan. Nepartak is moving to the west-northwest at 18 knots (20.7 mph/33.3 kph).

The Joint Typhoon Warning Center noted that "passage over very warm water, low vertical wind shear, and favorable outflow enhanced by an upper-level trough to the northwest are supporting the rapid intensification trend."

Nepartak is forecast to move northwest and is expected to intensify to 125 knots (143 mph/231 kph) over the next two days. The Joint Typhoon Warning Center forecast calls for the tropical cyclone to cross over northern and then over far eastern China before reemerging into the Yellow Sea.