It's located around 1,200 miles west-northwest of The Azores, with winds that have picked up a little to 45 mph as it moves north-northeast at 9 mph.
While the category 4 storm is forecast to weaken during the next 48 hours, Hector is expected to remain a major hurricane.
NHC noted that nearby Tropical Storm John is going to have an adverse effect on Ileana.
Debby transitioned to a tropical storm Wednesday morning with a greater concentration of storms near its center.
After getting off to a precocious start, with a tropical storm and two hurricanes already on its resume by July 8, the Atlantic hurricane season has been on hiatus. It was likely to bring rain to the southern part of peninsula as well as heavy surf.
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. Forecasters note that hurricane-force winds extend up to 35 miles from the center of the storm, and tropical-storm-force winds extend outward up to 105 miles.
Hector is expected to pass 200 miles South of the big island of Hawaii on Wednesday.
"Very rough surf is expected to impact mostly south- and east-facing coastal areas of the Big Island", AccuWeather meteorologist Dan Kottlowski said.
Closer to the USA mainland, Hurricane John is strengthening in bathlike ocean water south of the Baja Peninsula. But Big Island politicians live on top of one of the world's most active volcanoes and in the general vicinity of hurricanes that barrel through the central Pacific Ocean many summers.
The National Oceanic and Atmospheric Administration will release its updated mid-season hurricane forecast on Thursday.