Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 05/22/2026 11:31:00 AM UTC

                        
820
FXHW60 PHFO 220131
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
331 PM HST Thu May 21 2026

.SYNOPSIS...
Breezy to locally windy trades will weaken slightly Friday into
Monday and will then hold at moderate strengthen through the
remainder of the week. Showers will favor windward and mauka
areas, with little rainfall over most leeward sections.

&&

.DISCUSSION...
Locally windy trades are in place this afternoon and should
persist tonight. A robust 1034 mb surface high centered about
1,000 miles north of the islands is driving the strong trade wind
flow, and little change is expected overnight. Meanwhile, mid
level ridging will continue to produce stable conditions and cause
the trades to become accelerated over and downwind of prominent
terrain. As a result, a Wind Advisory remains in place for
portions of Maui County and Big Island through tonight. Even
though the atmosphere is stable and precipitable water is near to
below seasonal average, showers have been somewhat active over
some windward areas, especially on Big Island. Expect the trades
to continue to focus rainfall over windward and mauka areas, as
well as over the Kona slopes of the Big Island each afternoon.
Other leeward sections should see little rainfall.

Modest changes are expected on Friday. The surface high will start
to slowly weaken, leading to borderline Wind Advisory conditions.
Given uncertainty, we will leave it to the night shift to decide
whether or not to extend the advisory, which currently expires at
6 AM. Little change in the the rainfall pattern is expected, with
showers generally light to moderate and focused windward.

Trades will drop a notch during the weekend but will still remain
breezy through the Memorial Day holiday. The surface high driving
the winds will weaken slightly but remain at around 1029 mb,
strong enough to produce breezy trades. Stable conditions will
continue, and modest windward rainfall and a few afternoon showers
over the Kona slopes are expected. Moderate trade winds will
prevail Tuesday through the middle of next week.

&&

.AVIATION...
A tight pressure gradient back across the islands from high
pressure located far northeast of the state will produce fresh to
near gale-in-gust trade winds the next couple of days. Greater
stability from mid to upper level ridging expanding in from the
north and west, along with drier air moving in around the eastern
edge of this ridging, will result in less frequent showers. Most
light precipitation will impact windward exposures and high
terrain, especially during the overnight evening and early
morning hours.

AIRMET Tango remains in place to account for low level turbulence
over and downwind of terrain. This AIRMET will remain in place the
next couple of days in response to high winds and stability.

&&

.MARINE...
The strong high pressure ridge north of the Hawaiian Islands will
maintain easterly trade winds in the strong to gale range through
Friday morning. A Gale Warning remains in effect for the
Alenuihaha and Pailolo Channels, and Maalaea Bay. The Gale Warning
may need to be extended through the day Friday as there does not
seem to be much change in the strength of the high pressure. The
Small Craft Advisory (SCA) for all remaining island waters has
been extended through the day Saturday. Expect SCA to continue
into the first half of next week for all or portions of the state.

A high surf advisory (HSA) remains in effect for all east facing
shores through Friday afternoon due to strong trade wind swell
holding into the weekend. Winds may ease a touch tonight allowing
surf to drop below advisory levels Friday afternoon through the
weekend but conditions will remain borderline and thus will
continue to monitor in case there is a need to extend the HSA.

Surf along north facing shores will remain small into Friday. The
next small north- northwest (330 degree) swell will move into the
Hawaii region Friday afternoon, gradually increasing surf heights
along north and west- facing shores through the weekend.

A series of small, long-period south swells will support near-
average surf along south-facing shores over the next several
days.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 PM HST Friday for Olomana-Kahoolawe-
Maui Windward West-Kauai North-Kauai East-East Honolulu-Koolau
Windward-Molokai Windward-Molokai Southeast-Windward Haleakala-
Kipahulu-South Haleakala-Big Island Southeast-Big Island East-
Big Island North.

Wind Advisory until 6 AM HST Friday for Lanai Mauka-Kahoolawe-
Maui Windward West-Maui Leeward West-Kohala-Molokai-Lanai
Windward-Lanai Leeward-Lanai South-Maui Central Valley North-
Maui Central Valley South-South Haleakala-Big Island South-Big
Island Southeast-Big Island North.

Small Craft Advisory until 6 PM HST Saturday 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-Big Island
Windward Waters-Big Island Leeward Waters-Big Island Southeast
Waters.

Gale Warning until 6 AM HST Friday for Maalaea Bay-Pailolo
Channel-Alenuihaha Channel.

&&

$$

DISCUSSION...Wroe
AVIATION...Blood
MARINE...Almanza