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Hurricane Season 2010: Tropical Depression 17W (Northwestern Pacific)
October 22, 2010

NASA's Aqua Satellite Sees 17th Tropical Depression Form in NW Pacific

AIRS image of the small Tropical Depression 17W's cold (purple and blue) thunderstorms taken on Oct. 21 › View larger image
This infrared image of the small Tropical Depression 17W's cold (purple and blue) thunderstorms was taken by the AIRS instrument on NASA's Aqua satellite on Oct. 21 at 1459 UTC (10:59 a.m. EDT). The purple areas indicate high, cold thunderstorm cloud tops colder than -65 Fahrenheit.
Image Credit: NASA/JPL, Ed Olsen
The Northwestern Pacific Ocean continues to be active and NASA's Aqua satellite saw the seventeenth tropical depression form.

The Atmospheric Infrared Sounder (AIRS) instrument that flies on NASA's Aqua satellite uses infrared technology to take a tropical cyclone's temperature. AIRS captured an image of those cloud top temperatures of Tropical Depression 17W (TD17W) on Oct. 21 at 1459 UTC (10:59 a.m. EDT) revealing some strong thunderstorms colder than -65 Fahrenheit, around the center of this small depression.

Animated infrared satellite imagery and an image from NASA's Tropical Rainfall Measuring Mission satellite both show tightly curved low-level banding of thunderstorms wrapping into the center. However, most of the deep convection (rising air that forms thunderstorms that power a tropical depression) and rainfall are being pushed to the southwest of the center due to moderate northeasterly wind shear.

On Oct. 22 at 11 a.m. EDT, TD17W had maximum sustained winds near 34 mph. It was about 620 nautical miles northeast of Saipan, moving northwestward near 11 mph.

Saipan is the largest island of the U.S. Commonwealth of the Northern Mariana Islands, a chain of 15 tropical islands belonging to the Marianas archipelago in the western Pacific Ocean.

TD17W is now tracking northwest but it is forecast to change direction and move to the north, possibly dissipating over open waters this weekend.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.