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000
FXHW60 PHFO 211329
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
329 AM HST Sun Apr 21 2024

.SYNOPSIS...
Moderate trade winds will hold today with breezy to locally
strong trades returning from Monday onward. 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 remain in the forecast.

&&

.DISCUSSION...
Hawaii radar imagery shows brief passing showers are drifting in
on the moderate trade winds this morning. These relatively stable
light showers will decrease in coverage just after sunrise as more
stable high pressure begins to fill in over the islands. A high
pressure center will build into the Hawaii region just north of
the islands later tonight. Responding trade winds will increase
into the breezy to locally windy range for much of this week.
Passing showers are forecast, mainly along windward slopes in the
overnight to early morning hours, as trade wind speeds increase
from Monday through Tuesday.

From Tuesday night into Thursday morning, model guidance continues
to suggest that a small band of unstable clouds will move from
northeast to southwest across all islands. Expect increasing
shower trends, favoring windward and mountain areas. The bulk of
these enhanced showers are expected to fall over East Maui and
the windward slopes of the Big Island. From Thursday onward,
typical trade wind weather will continue for the rest of the week.

Wind speeds over the highest summits of Mauna Kea and Mauna Loa
of the Big Island have fallen over the past six hours below wind
advisory thresholds. Forecast guidance continues to show
decreasing wind speed trends at summit level, therefore the Wind
Advisory for the Big Island summits was cancelled with the
morning forecast package.

&&

.AVIATION...

Light to locally moderate trade winds will continue through
tonight and into the coming week. Bands of low clouds and light
to moderate rain showers will impact mainly windward and mauka
areas. Brief MVFR ceilings and visibility are to be expected in
passing showers, otherwise VFR conditions will prevail all areas.

&&

.MARINE...
High pressure north-northwest of the state will drift east and
keep trade winds moderate to fresh today. The ridge of high
pressure should rebuild late tonight, which should produce fresh
to locally strong trade winds once again. A Small Craft Advisory
for the typical windy waters around Maui County and the Big Island
is likely to be issued tonight through the week as trade winds
look to remain dominant.

A moderate medium period north swell has begun to rise at the
nearshore PacIOOS buoy 51201 overnight bringing an increase in
surf for north facing shores today. This swell will peak later
today below High Surf Advisory levels and steadily decline Monday.
Surf along east facing shores will remain small today, except for
shores exposed to the north swell which could see a slight rise.
As the trades strengthen early this week, short period wind waves
will bring elevated seas. South facing shores will continue at
small levels as a series of small, medium to long period energy
will persist over the next several days.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Bohlin
AVIATION...Bedal
MARINE...Shigesato