Hurricane Ignacio intensified as it blew across the Pacific on a route likely to bypass Hawaii on Saturday, said the Central Pacific Hurricane Center of the National Weather Service.
With winds gusting up to 115 miles per hour (185 kmph), the hurricane centered 835 miles (1,344 km) southeast of Honolulu and 625 miles (1,006 km) south east of Hilo was moving northwest at 8 miles per hour (13 kmph), said center spokesman Neil Honda.
"It just became a hurricane from a tropical storm," Honda said, noting the weather became fierce enough to be classified a hurricane at 5 a.m. Pacific on Saturday.
"It will just pass by the islands," Honda said, noting it could blow by later on Saturday morning. "There might be some wind and surf."
Sunday into Monday waves as high as 20 feet (4 meters) were expected, along with sustained winds of 39 miles per hour (63 kmph), he said.
Hawaii officials urged residents to prepare in the event the storm hits the island early next week.
Governor David Ige signed an emergency proclamation on Friday freeing up funds for disaster relief and allowing the suspension of certain laws that could impede "emergency functions".
Farther away than Ignacio, Hurricane Jimena in the Pacific Ocean about 1,900 miles (3,058 km) to the southeast of the Big Island of Hawaii was moving to the west-northwest at a speed of 9 miles an hour (14 km/h), according to the National Weather Service.
The Category Four hurricane poses no immediate threat to land, according to the Weather Service. It is expected to remain a major hurricane through Monday.
(Reporting by Barbara Goldberg in New York and Alex Dobuzinskis in Los Angeles; Editing by Raissa Kasolowsky and Franklin Paul)