113
FXHW60 PHFO 070204
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
404 PM HST Sat Dec 6 2025

.SYNOPSIS...
Moderate trade winds with embedded showers favoring mainly
windward and mauka areas are expected into Sunday, followed by
drier conditions early in the work week. By Tuesday and Wednesday,
winds will become light and veer southerly as a front approaches
the state from the northwest. The front is expected to move over
the state during the second half of the week bringing increased
shower chances.

&&

.DISCUSSION...
During the day today, the surface trough west of Kauai has
continued to weaken and lift northwestward away from the main
Hawaiian Islands. Meanwhile, drier conditions have been observed
across the state today, with latest satellite and radar imagery
showing very few clouds or showers. Also of note, episode 38 of
the ongoing Kilauea eruption began this morning just before 1900
UTC, sending a plume composed primiarily of water vapor and sulfur
dioxide gas (possibly with Pele`s hair and ash) to near 35,000
feet. This plume then spread eastward over portions of the Puna
District due to strong westerly flow aloft. However, as of 0130
UTC, radar echo tops and webcams show that emissions from Kilaua
have reduced and lowered back down to about 20,000 feet, and are
now being transported in the more typical southwesterly direction
within northeasterly flow.

Moderate trades will continue to decrease slightly tonight as an
upper level trough moves overhead. This slight instability
overnight could help provide some enhanced showers, but these
should be brief and mainly focused along windward and mauka areas.
Model guidance is also suggesting that a band of moisture,
currently seen on regional satellite imagery within the offshore
waters to the east, will arrive during the morning hours on
Sunday, sustaining windward shower chances for mainly the eastern
end of the state.

The upper level trough is expected to continue digging southeast
of the state Sunday and eventually form a closed low east of the
state early Monday. As low and mid level ridging builds in from
the west, stable and mostly dry conditions are expected with
moderate trade winds. Any showers that do occur would be a result
of brief pockets of low level moisture trapped within the trade
wind flow, and would mainly focus along windward and mauka areas.
The one exception is for the Kona slopes of the Big Island, where
typical sea-breeze induced cloud buildups and a few showers will
be possible during the day.

Models continue to indicate that a cold front will approach the
main Hawaiian Islands from the northwest Tuesday. As this occurs,
background surface winds will become light and veer southeasterly,
allowing for daytime sea breezes and nighttime land breezes ahead
of its arrival. Timing and impacts of the front remain uncertain,
with the ECMWF offering an earlier arrival late Wednesday and
more modest impacts than the GFS`s later arrival on Thursday with
stronger lift and upper level support for enhanced shower chances.
Will continue to monitor and update the forecast with the latest
details as they become more clear over the next couple of days.

&&

.AVIATION...
Moderate east to east-southeast tradewinds will continue through
tomorrow. A slightly drier airmass settled over the state will
continue limiting shower activity through the evening and
overnight hours. Brief MVFR conditions are possible with passing
showers primarily over windward and mountain areas. VFR conditions
will prevail.

Kilauea`s eruption earlier this morning produced an ash cloud
reaching FL350, but has continued to decrease in altitude
throughout the afternoon. SIGMET series Sierra covers the ash
cloud, and will likely be dropped tonight as impacts diminish.

No AIRMETs are currently in effect, but an AIRMET Tango for
moderate turbulence between FL290-FL360 will likely be needed
tonight as an upper level trough moves down the island chain
starting from Kauai. This is expected to continue into tomorrow,
affecting islands from Kauai through Maui.

&&

.MARINE...
A surface high pressure ridge will remain centered to the far
northeast of the main Hawaiian Islands, producing moderate to
locally fresh trade winds this evening that are expected to
slowly decrease from Sunday onward. Lighter southeast to south
winds are forecast from Tuesday into Wednesday as a cold front
moves into the region from the northwest. A consensus of weather
model guidance suggests this cold front may move into the western
Hawaiian islands from late Wednesday into Thursday.

The current medium period north-northwest (340-350 degree) swell
continues to slowly decline this afternoon. Buoy observations and
swell model guidance trends agree that this north-northwest swell
energy will gradually fade into Monday, bringing surf back down
to below average levels for this time of year. The next two long
to medium period overlapping northwest (310-320 degree) swell
pulses will arrive on Monday and Tuesday, boosting surf along
north and west facing shores and possibly reaching marginal
advisory levels by Wednesday.

Choppy east shore surf will remain small and decline this weekend
as trades gradually ease. Expect minimal background energy for
south facing shores through the next few days, despite a slight
bump this weekend.

Peak monthly tides combined with water levels that are running
higher than predicted will likely lead to minor flooding along
the shoreline and in low-lying coastal areas. Coastal flooding is
possible around the early morning peak tide through Sunday.

&&

.FIRE WEATHER...
Despite drier air in place over the state, moderate to light
winds will prevent reaching critical fire thresholds into early
next week. Light southeast winds are expected Tuesday and
Wednesday preceding a wetter weather pattern middle to second
half of next week.

&&

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

&&

$$

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