535
FXHW60 PHFO 281323
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
323 AM HST Sun Apr 28 2024

.SYNOPSIS...
Moderate trades will prevail over the eastern islands through the
first half of the work week, while lighter trades over the
western islands allow for some leeward land and sea breezes. A
plume of moisture will keep some showery weather over Kauai today,
while drier conditions overspread the remainder of the state. The
rather dry weather will persist through Tuesday, with a few
showers possible over interior and leeward areas each afternoon,
while showers will remain limited to mainly windward areas at
night. The trades will rebound Tuesday night and Wednesday,
bringing a return of more typical trade wind weather. The trades
will become breezy Thursday through next weekend, and the trade
wind showers may increase as well due to a disturbance aloft
moving over the islands.

&&

.DISCUSSION...
Currently at the surface, a front is located around 550 miles
west-northwest of Kauai, while a 1029 mb high is centered around
1350 miles northeast of Honolulu. Moderate trade winds prevail
in unsheltered areas over the eastern end of the state, while
light to moderate trades persist over the western islands.
Infrared satellite imagery shows partly to mostly cloudy
conditions across the state. Radar imagery shows scattered
showers moving into windward slopes and coasts, with a few
showers also in leeward areas of Kauai and Oahu. Main short term
focus revolves around trade wind trends and rain chances during
the next few days.

A front northwest of the state will gradually weaken into a trough
during the next few days as it edges slowly eastward. A slight
easing of the trades can be expected as we head into the first
couple days of the upcoming work week. Overall, moderate trades
look to hold on over the eastern islands, while lighter trades
prevail over the western islands, allowing some leeward sea and
land breezes to develop. We should see the trades start to rebound
beginning Tuesday night as the trough west of the state begins to
shift westward. Moderate to locally breezy trades should
overspread the state by late Wednesday, with the trades becoming
breezy across the entire island chain Thursday through next
weekend.

As for the remaining weather details, the band of moisture which
brought rather showery weather to most windward areas overnight is
in the process of breaking up as drier air works in from the east
and mid-level ridging begins to build overhead. Scattered showers
will continue to affect windward areas early this morning, with
shower activity then limited to primarily leeward and interior
areas this afternoon. A more showery pattern is expected across
Kauai today as the band of enhanced moisture will be slower to
exit here.

From tonight through Tuesday, relatively dry conditions should
prevail across the island chain. Brief passing showers will be
possible in windward areas each night, with a few showers
developing over interior and leeward areas each afternoon. We
should see a return to more typical trade wind weather Tuesday
night and Wednesday, with wetter trade wind weather potentially
developing Friday through next weekend as upper troughing sets up
over the state.

&&

.AVIATION...
Moisture riding in on the light to moderate ESE trades will
continue to provide a steady supply of showers to windward and
mauka areas of the Hawaiian Islands through the morning hours,
with tempo MVFR conditions expected within heavier showers. With a
SE element to the winds, showers will occasionally be steered
across leeward areas as well.

Drier air will move in from the east later today, allowing
conditions to improve across most of the state, but moisture will
linger across Kauai through the period. With the lighter flow and
decreased cloud cover, sea breeze activity will be possible
across protected areas mainly during the afternoon hours.

AIRMET Sierra for mountain obscuration is in effect for portions
of the Big Island and Molokai through Kauai. This AIRMET will
likely be needed through the morning hours before conditions begin
to improve.

&&

.MARINE...
Surface high pressure centered roughly 1200 nm northeast of the
state and an approaching weak front to the northwest will drive
breezy east southeast winds today, especially across all windward
waters and through the channels surrounding Maui County and the
Big Island. Through early this week, the aforementioned surface
high will drift eastward and allow flow to weaken. By mid-week,
high pressure will rebuild to the north and allow easterly flow to
strengthen again.

A Small Craft Advisory for winds will remain in effect for most
waters and channels surrounding Big Island, Maui, and Molokai
through Monday morning, then likely be dropped as winds weaken.

Surf heights will remain below advisory thresholds for all shores
through the forecast period. A small northwest, medium-period
swell will persist through mid-week with small surf expected.
Breezy east or east southeasterly flow will produce choppy surf
along east facing shores through tonight, then decrease as winds
begin to taper off early in the week. Small, short- period
southeast, and small medium- period south swell will continue into
mid-next week. Surf heights along the south facing shores should
remain near or slightly below seasonal norms.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Monday for Maui County
Windward Waters-Pailolo Channel-Alenuihaha Channel-Big Island
Windward Waters-Big Island Leeward Waters.

&&

$$

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