600
FXHW60 PHFO 301353
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
353 AM HST Tue Dec 30 2025

.SYNOPSIS...
A trough associated with the dissipated cold front northwest of
Kauai will continue to drift northwestward away from the islands.
The high pressure ridge will build back in from the north through
the afternoon hours with winds shifting from a more easterly
direction. A brief period of enhanced showers will develop over
each island as these breezy trade winds return. The next round of
enhanced showers will move in from the north, along a backdoor
cold front, from Thursday night through at least Friday. Some of
these enhanced cloud and shower trends may linger into early
Saturday. Drier island weather trends from Sunday to Monday.

&&

.DISCUSSION...
The big picture satellite imagery appears rather cloudy this
morning, as the subtropical jet stream spreads an abundance of
high level cirrus and mid level altocumulus clouds across the
entire state. In the low levels a weakening trough, associated
with a dissipated cold front, northwest of Kauai will continue to
lift northwestward away from the islands. This diminishing trough
will allow the high pressure ridge to build back into the islands
from the north. The current east-southeasterly wind regime will
be swiftly replaced by moderate to breezy easterly winds. A cloud
band likely produced by the convergence of these stronger
easterly winds will slowly move into the eastern or windward
slopes of the Big Island over the next several hours. Expect this
cloud band to drift westward throughout the day, briefly
enhancing clouds and showers as it passes through each island.
This cloud band moves through the Big Island and Maui this
morning, reaching Molokai and Oahu around noon HST, and finally
passing through the western islands of Kauai and Niihau through
the afternoon hours.

High pressure aloft will produce stable conditions and keep fair
weather in the forecast from New Year`s Eve through New Years Day
with only brief passing showers, mainly over windward and
mountain areas in the overnight to early morning time periods.
Moderate to locally breezy easterly trade winds will continue to
blow through New Year`s day, keeping the fireworks smoke from
settling in.

Another round of enhanced showers will move in from the north,
along a backdoor cold front, from Thursday night through at least
Friday. THese cloud and shower trends from this frontal band may
linger into early Saturday for some areas. Global weather model
solutions are uncertain on the ending of this period of this enhanced
shower activity. The American (GFS) model shows the frontal band
stalling over the islands, a longer duration wet trade wind
solution. While the European (ECMWF) model builds a stronger high
pressure system just north of the state, driving this frontal band
quickly through the region, a shorter duration and drier
solution. We decided to take a blend of operational models for
this medium range forecast, however our confidence remains only
moderate on precisely when these enhanced showers will end over
each island this weekend. Drier island weather trends should
return across the region from Sunday into early next week.

&&

.AVIATION...
East-southeasterly large scale winds will become more easterly and
strengthen later today as a wind convergence cloud band drifts
from east to west down the island chain. Expect a brief period of
enhanced showers as this smaller scale band passes through each
island. Mostly VFR conditions will prevail, except brief periods
of MVFR conditions in showers as the convergent cloud band moves
through the Big Island and Maui this morning, then Molokai and Oahu
around noon HST, and finally reaching Kauai and Niihau by the
early afternoon hours.

AIRMET Sierra for mountain obscurations may be needed over
windward areas from Big Island to Oahu later this morning as
a band of clouds and showers moves through the region.

&&

.MARINE...
Moderate to locally strong easterly trade winds return to the
coastal waters today and will continue through the week as high
pressure builds north of the islands. A Small Craft Advisory
remains in effect for the typically windy waters around Maui
County and the Big Island, and has been extended in time through
Wednesday afternoon.

Overlapping moderate to large, medium period northwest (320-340
degree) and north-northwest (340-350 degree) swells will maintain
advisory-level surf with very minor fluctuations through
Wednesday. Recent buoy observations show that this swell is
running around 2 feet above guidance at this time, so have
maintained the High Surf Advisory for north and west facing shores
of Niihau, Kauai, Oahu, Molokai, and north facing shores of Maui,
and extended it in time through the day on Wednesday. This swell
will then gradually decline from late Wednesday through the rest
of the week, with surf falling back below advisory criteria at
that time. Additionally, seas could flirt with 10 ft Small Craft
Advisory criteria across exposed waters during the peak of the
swell, but have maintained a max of 9 feet (just under SCA seas
criteria) in the forecast at this time based on latest guidance
and buoys.

Choppy east shore surf will continue though mid-week as locally
breezy trade winds strengthen. Surf along south facing shores
will remain tiny to small through the forecast period.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 PM HST Wednesday for Niihau-Kauai
Leeward-Waianae Coast-Oahu North Shore-Maui Windward West-Kauai
North-Molokai Windward-Molokai North-Molokai West-Maui Central
Valley North-Windward Haleakala.

Small Craft Advisory until 6 PM HST Wednesday for Pailolo
Channel-Alenuihaha Channel-Big Island Windward Waters-Big Island
Leeward Waters-Big Island Southeast Waters.

&&

$$

DISCUSSION...Bohlin
AVIATION...Bohlin
MARINE...Vaughan