383
FXHW60 PHFO 090204
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
404 PM HST Wed Oct 8 2025

.SYNOPSIS...
Light southerly flow will prevail into Friday, with overnight
land breezes and daytime sea breezes. Moisture ahead of a trough
to our north will support scattered to numerous showers near the
western end of the state for the next couple of days. Moderate
trades look to return by late Friday as this trough washes out and
surface high pressure northeast of the state becomes re-
established.

&&

.DISCUSSION...
This afternoon, a northeast to southwest oriented surface trough
is located near the western islands just outside of the Hawaiian
coastal waters. Ahead of this feature, light southerly winds are
prevailing over the island chain. Over the western end of the
state in the vicinity of the trough near Kauai and Oahu, enhanced
moisture is producing scattered to numerous showers that are
moving south to north embedded within the light southerly flow.
Latest satellite and radar imagery shows that most of these
showers are currently located in the Kauai Channel and in the
southwest coastal waters of Kauai and Oahu, but they continue to
track to the north towards the southern shores of those two
islands. Meanwhile, afternoon sea breezes have also developed due
to the weak background flow, increasing clouds and showers over
interior sections of all islands.

This same general weather pattern will persist through Friday,
though as the boundary lifts northward and begins to wash out, the
best rain chances from showers moving in from the south will shift
to focus mainly on Kauai Thursday and Friday. Elsewhere, expect
another couple of days of enhanced cloud cover and showers over
interior and leeward areas as daytime sea breezes take hold from
late morning through the evening hours. During the overnight
hours each night, land breezes will allow these interior and
leeward clouds and showers to largely diminish.

By late Friday, the trough will lift farther northward and high
pressure far to the northeast of Hawaii will become re-
established. This will mark a return of moderate trade winds this
weekend.

Early next week, global models show an upper low and developing
surface trough to the northeast again making its way closer to the
island chain. In this scenario, winds could once again weaken and
become more southeasterly as the trades are disrupted. Due to the
upper low`s close proximity to the western end of the state, an
increase in showers for Kauai and Oahu will again be possible.
Given the light southeastly flow, an overnight land breeze and
daytime sea breezes regime could become re-established.

By the middle of next week, global models differ significantly.
The GFS, for example, moves this next trough and upper low away
from the islands rather quickly, ushering trade winds back in by
mid-week. However, the ECMWF lingers the feature near the western
end of the state longer, and favors a continued land/sea breeze
pattern through much of next week. For now, have favored a
blended approach, but the extended forecast will likely need to be
refined as details become more clear over the next several days.

&&

.AVIATION...
A weak trough north of the state is supporting increased showers
over and near the western islands. Additionally, weak southerly
flow will produce daytime sea breezes and overnight land breezes
through Friday. This will result in increased showers and clouds
over island interiors and leeward sections during the day,
followed by clearing each night. The boundary is forecast to lift
north the next couple of days as it weakens, though shower chances
will continue to be greatest near Kauai through Thursday.

Although MVFR flight conditions (and even isolated IFR) will be
possible in any passing showers, there are currently no AIRMETs in
effect as VFR flight conditions prevail at most locations. It is
possible, however, that AIRMET Sierra may be needed later this
afternoon or tonight for mountain obscuration, particularly for
Kauai or Oahu.

&&

.MARINE...
A trough draped over the coastal waters will continue to slowly
drift northwest during the next couple of days and bring light
south or southeast flow across the region. This flow should also
give way to land and sea breezes that will be observed over the
nearshore waters. Gentle to moderate easterly trades will return
by this weekend and continue into early next week as high pressure
builds far northeast of the state.

The current small, medium period northwest swell will gradually
fade through the week`s end. This swell combined with a few short
period pulses from the north-northeast, and a small, medium
period northwest (320-330 degree) swell arriving on Saturday will
maintain surf below the October average along north-facing shores
through most of the week. Forerunners from the next, more
significant moderate, long period northwest (320 degree) swell
are progged to arrive by mid day Sunday, with the event lasting
through early to mid next week. During its peak, surf along north-
facing shores may approach High Surf Advisory criteria.

Background south-southwest swell energy will bring tiny to small
surf along south-facing shores through most of the week. A small,
long period south-southwest (190-200 degree) swell will fill in
Thursday morning and bring a slight increase to surf along south-
facing shores through late Friday, followed closely by a small,
long period southwest (220 degree) swell over the weekend.

Below average surf along east-facing shores is expected for the
remainder of this week as weak flow prevails. There will be a
slight boost by this weekend as trades return. In addition, a
small, medium to long period easterly swell from Tropical Cyclone
Priscilla in the East Pacific is forecast to arrive late Saturday
into Sunday.

Peak high tides associated with the lunar cycle will lead to
minor coastal flooding along shorelines and low lying coastal
areas through this weekend. Coastal flooding will coincide with
the daily peak tide each morning. A Coastal Flood Statement
remains in effect for all coastal areas through Friday, but will
likely need to be extended.

&&

.FIRE WEATHER...
Weak winds and a higher frequency of showers will help mitigate
fire weather concerns for the next several days. Inversion heights
across the state will range from as low as 5,000 to as high as
9,000 feet.

&&

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

&&

$$

DISCUSSION...Vaughan
AVIATION...Vaughan
MARINE...Farris
FIRE WEATHER...Vaughan