18 Aug 2016
NASA Sees Tropical Depression Dianmu Form near China's Hainan Island
An area of tropical low pressure that has been lingering in the northern part of the South China Sea for a couple of days has finally organized into a depression. NASA's Aqua satellite captured a visible light image of Tropical Depression Dianmu on Aug. 18.
On Aug. 17, the tropical low-pressure area known as System 95W was approximately 132.3 miles (115 nautical miles/213 km) southwest of Hong Kong. At 11 a.m. EDT (1500 UTC), animated enhanced infrared satellite imagery showed increased central convection associated with a consolidating low-level circulation center. The Joint Typhoon Warning Center (JTWC) said that System 95W had a defined low-level center with strong southwest monsoon winds wrapping up into it.
On Aug. 18, System 95W had consolidated and organized enough to be classified as a tropical depression. At 2:10 a.m. EDT (6:10 UTC) Tropical Depression Dianmu was spotted by the Moderate Resolution Imaging Spectroradiometer, or MODIS, instrument aboard NASA's Aqua satellite. Dianmu's center of circulation appeared to be just northeast of China's Hainan Island, while a thick band of thunderstorms in the south and western quadrant of the storm were over the island. The northern quadrant Dianmu did not appear to have as many storms. Bands of thunderstorms from the south and eastern quadrants over the South China Sea wrapped around the low-level center.
At 11 a.m. EDT (1500 UTC) on Aug. 18, 2016, Tropical Depression Dianmu was centered near 20.8 degrees north latitude and 109.2 degrees east longitude, about 62 nautical miles northwest of Haikou, China. Dianmu has tracked west at 18.4 mph (16 knots/29.6 kph) and is expected to continue moving in that direction. Maximum sustained winds were near 28.7 mph (25 knots/46.3 kph) and some slight strengthening is expected over the next day.
The JTWC expects Tropical Depression Dianmu to track west and make landfall in northeastern Vietnam on Aug. 19 and track over Hanoi before moving into Laos as it continues weakening.
Image: NASA's Aqua satellite captured this visible image of Tropical Depression Dianmu over southern China and Hainan Island on Aug. 18 at 2:10 a.m. EDT.