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000
FXHW60 PHFO 210147
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
347 PM HST Sat Apr 20 2024

.SYNOPSIS...
Moderate trade winds will hold through the weekend with breezy to
locally strong trades returning next week. An increase in
moisture is anticipated Tuesday into the middle of the week,
especially for the windward areas of Maui County and the Big
Island, where showery conditions will be possible.

&&

.DISCUSSION...
A 1028mb high far northeast of the state will continue to steadily
drift further northeast and away from the state tonight. This may
briefly weaken the trades a touch through tonight, but a new high
will rebuild north of the state Sunday into Monday and will
produce breezy trades by Monday. Looking out into next week,
breezy trades are expected through much of the week with
potentially strong trades during the second half of the week as
the high strengthens north of the state.

As far as rainfall, this afternoon`s satellite imagery shows
scattered showers over windward parts of the Big Island. For the
most part, rainfall amounts have decreased throughout the
afternoon but scattered showers should continue to persist
tonight. Over on the western half of the state, we have mostly
dry conditions with a few scattered showers over windward areas
this afternoon. For Sunday, we should see similar conditions as
today for the western half of the state with a few passing showers
primarily during the overnight and morning hours. For the eastern
half of the state, generally less rainfall is expected for Sunday
but scattered showers will continue to persist with an increase in
showers expected towards the evening. For next week, our main
moisture source looks to be the remnants of an old frontal
boundary moving in as early as Monday night into Tuesday. This
could bring some showery conditions for windward areas, especially
the eastern half of the state Tuesday through Wednesday night.
Otherwise, typical trade wind weather is expected with passing
showers from time to time.

Over on the summits of the Big Island, the High Wind Warning has
been extended through Sunday morning. Wind observations continue
to show wind gusts over 75 mph due to an upper level trough
swinging through the area. Winds should ease tonight, especially
after midnight as the upper trough moves away from the area.

&&

.AVIATION...
Light to moderate trades will persist through the rest of the
weekend. Bands of low clouds and light SHRA will impact windward
and mauka areas. ISOL SHRA over leeward areas are possible but
will be brief and light in nature.

AIRMET Sierra for mtn obsc is in effect for windward portions of
all islands from Kauai to the Big Island. Conds exp to improve
this evening.


&&

.MARINE...
High pressure building in from the north-northwest will drift east
and keep trade winds moderate to fresh through the weekend. The
ridge of high pressure should rebuild early next week, which
should produce fresh to locally strong trade winds once again.

The current south swell will steadily decline during Sunday. A
series of small, medium period swells will persist through the
weekend keeping south facing shores from going flat. Small, short-
period north swell will continue into the weekend. A larger
moderate medium period north swell reinforcement will arrive late
tonight. A rise in surf overnight is expected but the north swell
looks to peak Sunday well below High Surf Advisory levels. Surf
along east facing shores will remain small but can expect a slight
increase early next week as the trades strengthen.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 6 AM HST Sunday for Big Island Summits.


&&

$$


DISCUSSION...Kino
AVIATION...Walsh
MARINE...JVC