(BIVN) – An extra large northwest swell will produce “extremely dangerous giant size surf” for west-facing shores across Hawaiʻi, but Kona and Kohala will see smaller waves that are still big enough to trigger a warning.

National Weather Service in Honolulu issued a High Surf Warning for West Hawaiʻi until 6 p.m. HST on Monday. Large breaking waves up to 12 feet are expected.

“Expect very strong breaking waves and powerful currents,” the forecasters wrote. “Wave runup could impact coastal properties and infrastructure, as well as overwash low lying roadways, especially during morning high tide. Waves breaking in channel entrances may make navigating the channels dangerous.”

The swell will also generate strong surges and currents in exposed harbors through Monday. Honokohau and Kawaihae Harbors in West Hawaiʻi are likely to be affected.

Due to the High Surf Warning, the Hawaiʻi County Civil Defense advised:

• Expect waves to surge and sweep across beaches and coastal areas.
• Secure property and vessels prior to impacts.
• Beach-goers, swimmers, and surfers should exercise caution and heed all advice given by Ocean Safety Officials.
• Beaches and roads may be closed without notice.