UPDATE (March 21, 2018) – Hawaii Police Department reports Bayfront Highway in Hilo is closed in both directions due to the high surf.

(BIVN) – A High Surf Warning will go into effect starting at 6 a.m. Wednesday (March 21) and is expected to remain in place until 6 p.m. Thursday, forecasters say.

The National Weather Service in Honolulu says a large northeast swell will arrive tonight “and build rapidly, peaking from Wednesday into Wednesday evening, creating dangerous and potentially damaging surf along north and east facing shores.”

Surf will build rapidly late tonight and reach warning level early Wednesday morning, forecaster say. Wave heights could reach up to 25 feet.

Hawai‘i County Civil Defense issued an audio alert on Tuesday, saying that the highest threat “will coincide with the high tides, which occur tomorrow at 5 a.m. and 6:30 p.m.”

Due to the High Surf Warning, the county says the following are in effect:

• Oceanfront residents and beachgoers along the affected shores are advised to be on the alert for high and dangerous surf.
• Boat owners and oceanfront residents should take action to secure their property before nightfall.
• Roads and beach closures may occur without notice.

According to the National Weather Service:

Expect ocean water surging and sweeping across beaches, coastal benches, and lava flows creating the potential for impacts to coastal properties and infrastructure, including roadways. Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling, such as near Kahului and Hilo harbors.