The South China Sea and the Sulu Sea are side-by-side in the Western Pacific Ocean basin, and where they are separated by the Philippine island of Palawan, that’s where the newest tropical depression was sitting.

On Dec. 12 at 541 UTC (12:31 a.m. EST), the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA’s Aqua satellite captured an infrared image of Tropical Depression 19W’s clouds, which were centered over Palawan. Palawan is an island province of the Philippines located in the Mimaropa region that stretches from southwest to northeast. Palawan lies between the South China Sea to its west and the Sulu Sea to its east, and Tropical Depression 19W’s center was directly over Palawan at the time, and over both seas. AIRS data showed the thunderstorms in the center of Tropical Depression 19W’s were as cold as or colder than -63 Fahrenheit, indicating strong storms.

Tropical Depression 19W (TD 19W) formed on Sunday, December 12 in the morning hours (UTC) and is headed west-northwest toward Vietnam. At time it formed, it was about 325 miles east of Ho Chi Minh, Vietnam. Today, December 13, at 0900 UTC (4 a.m. EST), TD 19W’s maximum sustained winds had weakened to 20 knots (23 mph). It was about 225 nautical miles east of Ho Chi Minh City, Vietnam, near 10.3 North latitude and 110.1 East longitude. It was moving west-northwest at 5 mph.