318
FXHW60 PHFO 041320 CCA
AFDHFO

Area Forecast Discussion...CORRECTED
National Weather Service Honolulu HI
320 AM HST Mon May 4 2026

.SYNOPSIS...
Moderate easterly trade winds will persist today, with clouds and
light showers favoring windward and mauka areas during the early
morning hours. Trades will ease Tuesday as the surface ridge
weakens, bringing a transition to light winds, increasing
humidity, and land and sea breeze conditions through Thursday.
Showers will remain brief and mainly over interior and leeward
areas during the afternoons. Rainfall chances may increase by next
weekend as an upper disturbance and a weak front approach the
islands.

&&

.DISCUSSION...
Moderate easterly trades will remain in place today, with low
clouds and a few light showers focused over windward and mauka
areas. Leeward areas will remain mostly dry, with only isolated
passing showers possible.

Beginning Tuesday, the ridge north of the islands will weaken in
response to a series of cold fronts passing well north of the
state. This will lead to a gradual easing of the trade winds, with
local land and sea breeze circulations becoming more dominant
through midweek. From Tuesday through Thursday, a more humid air
mass will settle over the islands, with dewpoints potentially
climbing into the mid- to upper-60s. These dewpoints combined
with the afternoon sea breezes will support localized afternoon
cloud buildups and a few brief showers over interior and leeward
areas, followed by clearing at night as land breezes develop.

By the latter part of the week into the weekend, moisture and
rainfall chances may trend up. Global guidance indicates upper
heights lowering as an upper-level disturbance approaches the
region. In addition, a weak attendant frontal boundary may move
into the area. However, there remains considerable spread among
the model solutions regarding the timing and strength of these
features, so confidence in the details remains limited at this
time.

&&

.AVIATION...
Moderate trades continue, with clouds and brief showers expected
over windward sites. Periods of MVFR ceilings and visibility are
possible in showers, otherwise widespread VFR is expected. Trades
are expected to gradually weaken through the midweek.

AIRMET SIERRA is in effect for northern Oahu due to clouds and
showers, however conditions are expected to improve by daybreak.

&&

.MARINE...
Moderate to locally fresh trade winds will be in place today and
then weaken to land/sea breezes Tuesday and Wednesday as a front
to the northwest passes by to the north and weakens the ridge.
Gentle to moderate trade winds are expected to redevelop Thursday
and Friday before another front passes by to the north this
weekend and make winds light and variable.

A moderate northwest swell coming in a little below guidance will
build today and produce surf above seasonal average during the
peak tonight and early Tuesday. This swell will slowly decline
late Tuesday and Wednesday. A larger northwest swell could produce
surf near the High Surf Advisory level Thursday, then lower
Friday into next weekend.

A south-southwest swell will gradually decrease today and
Tuesday, with small pulses keeping surf from going flat for the
later half of the week.

Trade wind swell will lower below seasonal average today and will
remain small through the remainder of the week.
&&

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

&&
$$

DISCUSSION...Gibbs
AVIATION...Evans
MARINE...Tsamous