(CNN) Even as a months-long volcanic eruption goes on, Hawaii is now on alert for a dangerous hurricane forecast to pass south of the islands at midweek.

As of 5 p.m. Sunday local time (11 p.m. ET) Hurricane Hector was about to cross into the Central Pacific Basin as a Category 4 storm, the National Hurricane Center said.

Hector was about 1,130 miles (1,820 km) east-southeast of South Point Hawaii and traveling west at 14 mph (22 km/h), with maximum sustained winds of 140 mph (220 km/h), it said.

There are no coastal watches or warnings in effect but the center said the Hawaiian Islands should monitor the hurricane's progress.

"While the official forecast track continues to lie south of the Hawaiian Islands, only a slight deviation to the north of the forecast track would significantly increase potential impacts on the Hawaiian Islands. Now is a good time for everyone in the Hawaiian Islands to ensure that they have their hurricane plan in place," it said.