454
FXHW60 PHFO 061301
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
301 AM HST Sun Apr 6 2025

.SYNOPSIS...
A series of high pressure systems building to the northwest and
north of the state will keep trades blowing during the next 7
days. The trades will peak at breezy to windy levels today, then
ease to moderate and locally breezy levels Monday through late
next week. A band of moisture associated with an old front will
keep showery conditions affecting Kauai through Monday, while
drier trade wind weather persists across the remainder of the
state. The band of moisture will shift southward Monday night and
Tuesday, then meander across the islands through Thursday,
bringing periods of showery weather to windward areas. The deepest
moisture appears to lift back northward Friday and next Saturday,
allowing a more typical and uniform distribution of showers to
return to the island chain.

&&

.DISCUSSION...
Currently at the surface, a weakening stationary front is
located just north of the state, while a 1034 mb high is centered
around 1100 miles northwest of Honolulu. The resulting gradient
is producing breezy trades across the island chain early this
morning. Infrared satellite imagery shows variably cloudy skies in
windward areas with clear to partly cloudy conditions in most
leeward locales. Radar imagery shows scattered showers moving
into windward areas, with a brief shower occasionally reaching
leeward communities. Shower coverage is the highest on Kauai in
closest proximity to the stationary front. Main short term focus
revolves around rain chances and trade wind trends.

The strong high pressure system northwest of the state will peak
out at around 1035 mb later today. This in combination with
inversion heights lowering to around 6 kft this afternoon over
the eastern end of the state, will likely bring advisory level
winds to some of the windier areas of Maui County and the Big
Island. As a result, a Wind Advisory is now in effect for portions
of Maui County and the Big Island through 10 PM this evening.

The high will weaken slightly tonight and Monday, but the
gradient locally will remain quite strong keeping breezy trades
in place. A front passing by to the north of the state and a weak
trough moving in from the east should weaken the gradient Tuesday
into Wednesday, easing the trades to moderate levels. A new strong
high building north of the islands Thursday into next weekend,
could bring a return of breezy trades to the state.

As for the remaining weather details, the moisture associated with
an old front will remain in close proximity to Kauai through
Monday, keeping shower coverage the highest here, while drier
trade wind weather prevails over the remainder of the state. The
frontal remnants appear to push southward Monday night and
Tuesday, bringing an increase in shower coverage from Oahu to the
Big Island, with little change in the weather across Kauai. The
band of enhanced moisture will then meander over the islands
Tuesday night through Thursday, bringing periods of showery
weather mainly to windward areas, although the trades will allow
some showers to reach leeward communities at times as well. The
deepest moisture appears to lift back northward Friday and next
Saturday, allowing a more typical and uniform distribution of
showers to return to the island chain.

&&

.AVIATION...
Breezy to locally windy trades will persist through the next 24
hours bringing passing low clouds and showers to windward and
mountain areas. Moisture in the vicinity of a weakening
stationary front just north of the state will continue to deliver
low clouds and showers to windward Kauai, where the bulk of the
shower activity across the state will be focused. Periods of MVFR
or even brief IFR conditions can be expected in showers.
Otherwise, VFR conditions will prevail.

AIRMET Sierra remains in effect for mountain obscuration across
windward portions of Kauai.

AIRMET Tango remains in effect for low level turbulence downwind
of terrain due to the breezy to locally windy trades across the
state.

&&

.MARINE...
Rough marine conditions are expected through the remainder of the
weekend due to a combination of fresh to strong trade winds,
rough seas, and an ongoing long period north swell. Small Craft
Advisory conditions are expected across all Hawaiian waters and
may persist into Monday before gradually improving. Trade winds
are forecast to ease slightly on late Monday and Tuesday, then
rebuild by Wednesday. Seas should also dip below advisory levels
early next week as both the winds relax and the large weekend
swell subsides.

Due to the strength and direction of this northerly swell
(340-360 degrees), moderate to heavy harbor surges are
anticipated to continue in north-facing harbors through the
rest of weekend. A marine weather statement remains posted for
this hazard.

The ongoing extra large north swell will continue to bring warning
level surf to most north and east facing shores today, with advisory
level surf expected for many west facing coastlines. A steady decline
in surf is expected tonight through the middle of the week. A new
long- period swell may give a small boost to north and west shore surf
late Thursday and Friday, with very small surf then expected for next
weekend.

A series of overlapping small south swells should bring a boost
to south shore surf Monday through Thursday, with surf returning
to small mostly background levels Friday into next weekend.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Warning until 6 PM HST this evening for Niihau-Oahu
North Shore-Olomana-Maui Windward West-Kauai North-Kauai East-
Koolau Windward-Molokai Windward-Molokai North-Maui Central
Valley North-Windward Haleakala-Big Island East-Big Island North.

High Surf Advisory until 6 PM HST this evening for Kauai Leeward-
Waianae Coast-Maui Leeward West-Molokai West.

Wind Advisory until 10 PM HST this evening 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 South-Big Island
Southeast-Big Island North.

Small Craft Advisory until 6 AM HST Monday for all Hawaiian
waters-

&&

$$

DISCUSSION...Jelsema
AVIATION...Farris
MARINE...Jelsema