https://phys.org/news/2018-07-suomi-npp-satellite-compact-storm.html

At 5 a.m. EDT (0900 UTC) the Joint Typhoon Warning Center (JTWC) reported the center of Tropical Storm Son-Tinh was located near latitude 19.0 degrees north and longitude 107.4 degrees east. That's about 173 nautical miles southeast of Hanoi, Vietnam. Son-Tinh was moving to the west. Maximum sustained winds were near 46 mph (40 knots/74 kph).

The JTWC forecasts that Son-Tinh will continue to track westward along the southwestern edge of a subtropical ridge (elongated area) of high pressure. Despite unfavorable vertical wind shear the storm will track through warm sea surface temperatures and slowly weaken.