Hurricane John was centered about 320 miles (515 kilometers) southwest of the Mexican port of Manzanillo, with maximum sustained winds of 75 mph (120 kph) late in the afternoon.
However, the margin of error still takes the center very close to the southern Big Island, and while it's still too early to specify exact impacts on the islands, there's still a chance for tropical storm force winds and heavy rain for much of the island.
The National Weather Service (NWS) briefed Hawai'i Emergency Management Agency (HI-EMA), local emergency management and civil defense agencies, and federal and state partners Monday morning, August 6, 2018, about Hurricane Hector, which has reached Category 4 strength. Forecasters expect Hector to move west-northwest for the next two days.
For now, there could be enhanced heavier showers for east Hawaii island starting Wednesday morning.
With winds of 155 miles per hour, it is just shy of Category 5 intensity, which begins when sustained wind speeds reach 157 miles per hour.
As of 11 a.m., Hurricane Hector was about 850 miles east-southeast of Hilo.
Far out to sea, a strengthening Hurricane Hector was in the central Pacific as a strong Category 4 storm, with winds of 155 miles per hour (250 kph), the Center Pacific Hurricane Center in Honolulu reported.
"Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km)".
Hector also posed no immediate threat to land, but forecasters said people in Hawaii should monitor the storm's progress as it was projected to pass just south of the islands by midweek.
Hector is in an area with low vertical wind shear, which has allowed it to intensify into a powerful hurricane.
Most of the forecast guidance is now unanimous, saying the tropical storm will remain south of the rest of the Hawaiian Islands through Thursday.
People are being warned swimming and boating will be unsafe towards the end of the week as rough seas and strong rip currents will affect eastern and southern-facing coasts.