https://phys.org/news/2018-09-infrared-nasa-hurricane-olivia-strongest.html

Infrared data also provided forecasters with a look at surrounding sea surface temperatures (SSTs). Tropical cyclones require SSTs at least near 80 degrees Fahrenheit (26.6 degrees Celsius) to maintain strength. NHC forecasters noted at 5 a.m. EDT (0900 UTC) on Sept. 4 that "Olivia has about 24-36 hours or so remaining over warm SSTs with marginally favorable upper wind conditions."

At 5 a.m. EDT (0900 UTC), the National Hurricane Center or NHC noted the center of Hurricane Olivia was located near latitude 16.9 degrees north and longitude 117.2 degrees west. That's about 630 miles (1,015 km) southwest of the southern tip of Baja California, Mexico.