System 91W appears ripe to become Tropical Depression 4 in the next couple of days as it continues moving north and parallels the east coast of the Philippines. NASA's Aqua satellite captured a visible image of the developing low pressure area as it passed overhead in space on June 17.
On June 16 at 2200 UTC (6 p.m. EDT) System 91W was located near 13.5N and 126.9E, about 355 miles east-southeast of Manila, Philippines.
NASA's Aqua satellite passed over System 91W on June 17 at 05:08 UTC (1:08 a.m. EDT) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard captured a visible image of the consolidating storm. Satellite imagery showed strong bands of thunderstorms over the northern and southern quadrants of the storm. The low-level center of circulation appears to be consolidating, and the banding of thunderstorms around it have improved in the last day.
According to the Joint Typhoon Warning Center, System 91W has a high chance of becoming Tropical Depression 4 in the next day or two. Computer models indicate that it will continue tracking northward and parallel the coast of the Philippines over the next couple of days and residents along the coast can expect rough seas, gusty winds and rain as the low pressure area moves north.
Explore further: NASA satellite sees Tropical Storm Yagi just south of Japan