(BIVN) – The National Weather Service in Honolulu has posted a High Surf Advisory for west-facing shores of Hawaiʻi Island, in effect until 6 a.m. Monday.

Surf will be 6 to 9 feet along west facing shores of the Big Island, lowering to 5 to 8 feet tonight, forecasters say.

“The current large long-period northwest swell will hold through this morning, then gradually lower this afternoon through Tuesday,” the National Weather Service explained in its morning advisory. “Another large northwest swell is expected on Wednesday and will likely bring advisory level surf along exposed north and west facing shores.”

In a message about the High Surf Advisory issued on Saturday, the Hawaiʻi County Civil Defense said “beach-goers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution,” and reminded that “beaches may be closed without notice.”