Infrared imagery from NASA’s Terra satellite revealed Tropical Depression 13W contained some powerful thunderstorms pushing high into the troposphere as it was moving west in the Philippine Sea toward the Philippines.
Tropical Depression 13W has already triggered warnings in the Philippines because it is located just east of the country. Philippines warnings include Tropical cyclone wind signal #1 over the following Luzon provinces: Cagayan, Isabela, Quirino, Nueva Vizcaya, Apayao, Abra, Kalinga, Mountain Province, Ifugao, Benguet, Aurora, Nueva Ecija, eastern portion of Pangasinan, northern portion of Quezon including Polillo Island and Catanduanes.
NASA’s Terra satellite used infrared light to analyze the strength of storms and found the most powerful thunderstorms stretching north over the center from west to east. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.
On August 26 at 9:15 a.m. EDT (1315 UTC), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite found those strongest storms had cloud top temperatures as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.
At 11 a.m. EDT (1500 UTC), the center of Tropical Depression 13W was located near latitude 13.9 degrees north latitude and 128.5 degrees east longitude. That is about 498 nautical miles east of Manila, Philippines. 13W was moving toward the west and toward the Philippines. Maximum sustained winds are near 52 mph (45 knots/83 kph) with higher gusts.
The Joint Typhoon Warning Center expects 13W will move west across the Philippines, before turning northwest towards Hainan Island, China. The system will make final landfall in Vietnam after five days.
This part of information is sourced from https://www.eurekalert.org/pub_releases/2019-08/nsfc-nts082619.php