Surf on the north-facing shores could reach the 40- to 50-foot level on the outer reefs by Monday, according to the National Weather Service.

However, near-shore surf is usually smaller, said Jonathan Hoag, weather service forecaster.
Two exceptionally large storms in the central north Pacific are causing swells that will begin to hit the island tomorrow and Monday, Hoag said.
Today, surf along north-facing shores will be 8 feet to 10 feet rising tomorrow to 25 feet to 30 feet and as high as 40 feet on the outer reefs.
West-facing shores will be 3 feet to 5 feet today rising to 12 feet to 20 feet tomorrow.
Along the east-facing shores, waves will be 2 feet to 4 feet and rising to 6 feet and as high as 10 feet tomorrow on coasts exposed to the swell wrapping around.
South-facing shores will be 3 feet to 5 feet, with occasional 6-footers today through tomorrow.