High Surf in Hawaii, June 24 to 27, 2023

Area Forecast Discussion
National Weather Service Honolulu HI
326 AM HST Sat Jun 24 2023

.SYNOPSIS...
Trade winds will remain at breezy to locally windy levels through
early next week, peaking this weekend. The trades are expected to
ease slightly during the middle to latter part of next week.
Little change in the overall weather pattern is expected during
the next 7 days, with bands of clouds and showers moving through
the islands at times. Showers will favor windward and mauka
areas, particularly at night and during the early morning hours,
with a few showers occasionally reaching leeward communities due
to the strength of the trades.

&&

.DISCUSSION...
Currently at the surface, a 1028 mb high is centered around 850
miles north-northeast of Honolulu, and is driving breezy trade
winds across the island chain early this morning. Infrared
satellite imagery shows partly to mostly cloudy conditions across
the state, with cloud coverage the highest in windward and mauka
areas as well as leeward sections of the Big Island. Radar imagery
shows scattered to numerous showers moving into windward areas,
with some of these showers reaching leeward communities at times.
Main short term focus revolves around rain chances during the next
few days.

High pressure will remain nearly stationary to the north of the
islands through Tuesday, keeping breezy trade winds in place
across the island chain. The trade winds will peak at locally
windy levels this weekend as a drier more stable airmass builds
in and lowers inversion heights to around 5-6 kft. This should
allow the terrain to be particularly effective at accelerating the
winds through the islands. A a result, a Wind Advisory has been
issued for portions of the Big Island, Maui, Lanai and Kahoolawe
from 10 am this morning through 6 pm Sunday. The trades are
expected to ease back to moderate and locally breezy levels
Wednesday through late next week as the high to the distant north
weakens slightly.

As for the remaining weather details, typical trade wind weather
is expected to continue during the next 7 days, with the exception
of this weekend, when a drier more stable airmass should reduce
shower coverage statewide. Overall, bands of clouds and showers
will periodically move through the islands throughout the forecast
period, with showers favoring windward slopes and coasts,
particularly at night and during the early morning hours. A few
showers will reach leeward areas at times as well due to the
strength of the trades.

&&

.AVIATION...
Breezy to locally strong trade winds will continue through the
weekend. As a result, AIRMET Tango will remain posted for low
level turbulence over and downwind of the terrain of all islands.

Low clouds and showers will continue to favor windward and mauka
areas, with a few showers spilling over into leeward areas due to
the strong trades. Expect mainly VFR conditions across the area,
with periods of MVFR cigs and vsbys under SHRA. AIRMET Sierra for
mountain obscuration over windward sections of Oahu and the Big
Island will remain posted through the morning hours.

&&

.MARINE...
Small Craft Advisory level easterly trade winds (20-30 kt) and
associated rough seas are expected to continue through early next
week. Seas will reach the 8 to 12 ft range this weekend due to a
combination of a solid long-period south-southeast swell and the
short-period wind generated seas out of the east. Winds are
forecast to increase to near-Gale speeds today, mainly over the
Alenuihaha Channel. Latest ASCAT shows a solid area of strong winds
in this zone, thus will continue the Gale Watch, but this may need
to be upgraded to a Gale Warning later today.

Near shore buoys are already seeing an increasing in south swell
energy as the new south (170 degree) swell fills in. This swell
will continue to build today, peak tonight and hold through
Sunday. A High Surf Advisory has been issued for south facing
shores as surf builds to advisory levels (10 ft) today. A second
pulse is expected to arrive Monday, keeping surf well above
average through the first half of next week. Surf will return to
the summertime average late next week with more typical background
southerly energy moving through.

Surf along east facing shores will trend up and remain rough
through early next week due to the strong to near gale force
trades trades.

Surf along north and west facing shores will remain near the
summertime average through today, then slightly rise Sunday into
next week as a small northwest swell arrives.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Monday for Niihau-Kauai
Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai
South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai Southeast-
Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central
Valley South-South Maui/Upcountry-South Haleakala-Big Island
South-Big Island Southeast.

Wind Advisory from 10 AM this morning to 6 PM HST Sunday for
Lanai Mauka-Kahoolawe-Maui Windward West-Maui Leeward West-
Kohala-Lanai Windward-Lanai Leeward-Maui Central Valley North-
Maui Central Valley South-South Haleakala-Big Island North.

Small Craft Advisory until 6 PM HST Monday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters-Maui County Leeward Waters-Maalaea Bay-
Pailolo Channel-Big Island Windward Waters-Big Island Leeward
Waters-Big Island Southeast Waters.

Small Craft Advisory until 8 PM HST this evening for Alenuihaha
Channel.

Gale Watch from this evening through late Sunday night for
Alenuihaha Channel.

&&

DISCUSSION...Jelsema
AVIATION...Ahue
MARINE...Almanza