High Surf Warning issued December 21 at 3:51AM HST until December 23 at 6:00AM HST by NWS Honolulu HI

…HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU
KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI…
…HIGH SURF WARNING FOR WEST FACING SHORES OF THE BIG ISLAND…
…HIGH SURF ADVISORY FOR NORTH FACING SHORES OF THE BIG
ISLAND…

.An extended period of hazardous surf and beach conditions will
persist into early next week along exposed north and west facing
shores due to overlapping, winter-caliber north-northwest swells
(315-330 degrees). The largest swell in the series is expected
to arrive tonight, rapidly rise early Sunday, peak through the
day Sunday, and then gradually ease Sunday night into early next
week. Surf associated with this swell will remain well above
warning levels through the weekend, then return to advisory levels
for exposed north and west facing shores around Tuesday of next
week.

* WHAT…Surf of 30 to 40 feet, building to 40 to 50 feet Sunday
along north facing shores of Niihau, Kauai, Oahu, Molokai and
Maui. Surf of 15 to 25 feet, building to 25 to 35 feet Sunday
along west facing shores of Niihau, Kauai, Oahu, and Molokai.
Surf of 8 to 12 feet along west facing shores of the Big Island

* WHERE…North and west facing shores of Niihau, Kauai, Oahu,
Molokai, north facing shores of Maui, and west facing shores of
the Big Island.

* WHEN…Until 6 AM HST Monday, with a peak expected through the
day Sunday. The best chance for coastal impacts to properties
and roadways will be during the peak daily high tides through
the early morning hours.

* IMPACTS…Very High…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.