https://phys.org/news/2018-08-nasa-infrared-view-tropical-storm.html

Cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Hector was located near latitude 26.9 degrees north and longitude 174.5 degrees east. That's 1,079 nautical miles northwest of the Johnston Island Atoll. The Joint Typhoon Warning Center or JTWC said Hector is moving toward the west-northwest. Maximum sustained winds are near 40 mph (35 knots/62 kph) with higher gusts.