NASA finds wind shear battering Tropical Depression 16W

Tropical Depression 16W was still being battered by vertical wind shear, and appeared elongated for the second day in a row on satellite imagery from NASA-NOAA's Suomi NPP satellite.

On July 31 at 0224 UTC (July 30 at 10:24 p.m. EDT), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument that flies aboard NASA-NOAA's Suomi NPP satellite provided a visible image of Tropical Depression 16W in the Northwestern Pacific Ocean. VIIRS, a scanning radiometer, collects visible and infrared imagery and radiometric measurements of the land, atmosphere, cryosphere, and oceans.

The VIIRS image revealed that the bulk of clouds and showers associated with the tropical system were pushed to the north and east of the center. Strongest storms appeared north of the center, and aq fragmented band of thunderstorms were east of the center.

On July 31 at 5 a.m. EDT (0900 UTC) Tropical Depression 16W was located near 32.9 degrees north latitude and 150.8 degrees east longitude. That's about 518 nautical miles north-northwest of Minami Tori Shimi, Japan. 16W was moving to the north. Maximum sustained winds 25 knots (28.7 mph/46.3 kph).

The Joint Typhoon Warning Center or JTWC noted that "the asymmetric convection suggests the system is subtropical."

The JTWC forecast says that 16W will strengthen slightly but maintain tropical depression status as it curves to the northeast and remains over the open ocean.