888
FXHW60 PHFO 271302
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
302 AM HST Sun Apr 27 2025

.SYNOPSIS...
Light winds will prevail across the state during the next few
days. Sea breezes in combination with a moist airmass and a
disturbance aloft, will bring locally heavy showers and the
potential for a few rumbles of thunder to the islands each
afternoon. Land breezes will develop each night and keep most of
the shower activity offshore or near the immediate coast. A
return to more typical trade wind weather featuring mainly
windward and mauka showers appears take hold Wednesday, with
breezy conditions developing by Friday and continuing through next
weekend.

&&

.DISCUSSION...
Currently at the surface, a weak diffuse trough of low pressure
is located around 100 miles northwest of Kauai, while a 1028 mb
high is centered around 1650 miles northeast of Honolulu. Winds
remain light across much of the state, with land breezes present
in most areas. Infrared satellite imagery shows partly to mostly
cloudy conditions, with cloud coverage the highest over the
western islands. Radar imagery shows scattered showers over the
coastal waters and leeward coastal sections of Oahu, Molokai, and
the Big Island. A few showers are also moving into windward Big
Island, with very little shower activity elsewhere. Main short
term focus revolves around the potential for heavy rain and
thunderstorms during the next few days.

The weak trough of low pressure will shift slowly eastward
today and tonight, then settle over the islands Monday and
Tuesday. Winds will change little during this time, with land and
sea breezes dominant over most of the state. The troughing over
the islands will gradually dampen out during the middle and latter
part of the week as high pressure builds to the north. This
should allow a gradual return and strengthening of the trade winds
across the state, with the trades reaching breezy levels Friday
through next weekend.

As for the remaining weather details, the airmass over the
islands will gradually moisten up today through Tuesday as a weak
diffuse trough moves over the state. A land/sea breeze pattern
will remain in place, with showers favoring interior and leeward
areas during the afternoon and evening hours, and remaining mostly
over the coastal waters or areas near the immediate coast at
night. The airmass appears unstable enough this afternoon, that
some locally heavy downpours and a few rumbles of thunder will
remain possible. The airmass will further destabilize Monday and
Tuesday as a disturbance aloft dives southward over the state.
This is expected to bring a better chance for some locally heavy
rainfall and a few thunderstorms to the island chain. A return to
more typical trade wind weather featuring mainly windward and
mauka showers appears take hold Wednesday, with this pattern then
persisting through next weekend.

&&

.AVIATION...
A light flow pattern will allow for land breezes early this
morning, followed by sea breezes along coastal regions by this
afternoon. Conditions aloft will continue to become more unstable
through the remainder of today as an upper level trough drops
southward over the islands. Thus, heavier showers and isolated
thunderstorms will be possible, especially over interior regions
with the introduction of diurnal heating. MVFR ceilings and
visibility can be expected with some of the more robust activity.

AIRMET SIERRA for tempo mountain obscuration remains in effect
for Oahu above 2500 feet due to low clouds and showers.

&&

.MARINE...
A low pressure system northwest of Kauai continues to weaken the
high pressure ridge over the Hawaiian Islands. A diffuse trough
near the island of Kauai may bring some heavier showers and
thunderstorms to the nearby coastal and offshore waters. This
boundary is expected to slowly lift to the northeast over the next
few days increasing the potential for showers and thunderstorms
over the coastal and offshore waters. Light and variable winds
will continue into the first half of this week. Trades will build
back in from Wednesday onward as a high pressure system builds in
north of the Hawaii Region.

A small long period northwest swell will peak today, then fade
into Tuesday. Surf along north and west facing shores should
remain near or below average levels for this time of year. By
Thursday, a medium long period north northwest swell is expected
to enter the waters and produce surf that may approach advisory
levels.

Multiple small early season south swells will maintain small
background southerly energy through the middle of this week. A
bump up in south swell energy is expected to arrive late Thursday
and last through next weekend. Weak upstream trade wind flow will
keep surf along east facing shores near or below seasonal
averages.

&&

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

&&

$$

DISCUSSION...Jelsema
AVIATION...Thomas
MARINE...Bohlin