497
FXHW60 PHFO 300121
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
321 PM HST Fri Aug 29 2025

.SYNOPSIS...
Light to moderate trades will continue through next week, with
localized land and sea breezes at times. Mostly dry and stable
conditions will prevail, with the exception of a brief uptick in
shower activity possible Sunday into Monday.

&&

.DISCUSSION...
The typical trade-wind producing high pressure far northeast of
Hawaii remains displaced and weakened by a large area of low
pressure. This synoptic setup will maintain light to moderate
trades, with diurnal sea and land breezes developing across the
state, particularly in leeward and interior areas.

Through much of the forecast period, mid-level ridging and dry
air filtering across the region will limit shower activity,
supporting a generally dry and stable pattern. Brief showers will
mainly be confined to windward and mauka areas overnight into the
morning hours, though sea breezes may bring isolated light showers
to some leeward and interior areas each afternoon throughout the
period.

An interruption to this pattern may come Sunday into Monday as a
weak surface low tracks westward south of the Big Island. Moisture
associated with this feature may clip the southern half of the
island chain, bringing an uptick in showers, especially for
windward Big Island and Maui. At the same time, an upper level low
is forecast to stall northwest of Kauai, destabilizing the mid to
upper atmosphere near the western end of the state. This
combination of deeper tropical moisture and added instability,
although not aligned perfectly, could allow for the slight
enhancement of shower activity statewide, particularly from Sunday
afternoon through Monday.

Conditions should return to a more typical stable hybrid trade
wind and land-sea breeze pattern Tuesday onward, with light to
moderate trades resuming and drier conditions prevailing.

&&

.AVIATION...
A ridge just north of the islands will maintain light to moderate
trade winds into the weekend. Some localized daytime sea breezes
and overnight land breezes are possible. A relatively dry airmass
upstream of the islands will limit shower activity. The background
trade wind flow will focus any clouds and showers to the windward
sides of the islands, with some afternoon buildup over the west
and central parts of the Big Island. Overall, VFR conditions will
prevail with brief MVFR conditions possible in some of the clouds
and showers.

No AIRMETs are in effect and none are expected.

&&

.MARINE...
A ridge of high pressure north of the state will gradually shift
further south during the next day or so in response to a
developing low far north of the state. As the ridge nudges closer
to the islands our trade wind speeds will decrease with gentle to
moderate trade winds expected this weekend into early next week.
Winds should be light enough for localized sea breezes, especially
across leeward waters.

Observations at nearshore PacIOOS buoys south of the islands show
some reinforcing energy from the south in the 14-18 second energy
bands this afternoon. The reinforcing energy should help maintain
surf around the summer average through Saturday with a steady
decline expected Sunday into Monday. Surf heights will return to
background levels by early next week along south facing shores.

Surf along north facing shores will see a small, short period
swell expected to arrive late this weekend. This swell will be
overshadowed by longer period energy out of the northwest starting
Monday night of next week. This swell should peak on Tuesday and
could produce surf heights near the September average of 4 to 6
feet. Daytime ASCAT showed gale-force winds with the developing
low far north of the state. This should send another reinforcing
pulse out of the north around the same time the northwest swell
arrives. A mix of north and northwest swells are expected next
Tuesday through Thursday.

Below average surf is expected to continue along east facing
shores due to gentle to moderate trade winds persisting through
early next week.

Peak monthly high tides combined with water levels that are
running higher than predicted may lead to minor flooding along the
shoreline and in low-lying coastal areas toward the end of next
week. Coastal flooding may be possible around the daily peak
tide, which will be during the afternoon hours.

&&

.FIRE WEATHER...
While critical fire weather thresholds were approached this
afternoon across some leeward locations as relative humidities
fell into the mid to upper 30 percent range, trade winds generally
remained below criteria. The lighter trade winds are expected to
be the main limiting factor through next week, helping to keep the
state below critical fire weather thresholds, despite the high
stability and drier conditions that are generally expected to
stick around. Inversion heights will typically range between 6,000
to 8,000 feet.

&&

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

&&

$$


DISCUSSION...Farris
AVIATION...M Ballard
MARINE...Kino
FIRE WEATHER...Farris