Area Forecast Discussion
Issued by NWS Honolulu, HI

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250
FXHW60 PHFO 121357
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
357 AM HST Wed Nov 12 2025

.SYNOPSIS...
A broad high dominating much of the Central Pacific will maintain
breezy to windy trades across the Hawaiian Islands through
Thursday morning. Enhanced shower activity and cloud coverage
will persist predominately over windward and mauka areas. Trades
will begin to weaken to a more moderate regime by Friday in
response to the high weakening and propagating northeastward away
from the Hawaiian Islands.


&&

.DISCUSSION...
The latest surface analysis depicts a broad 1035 mb area of high
pressure well north of the Hawaiian Islands, maintaining breezy to
locally windy trades through early Thursday morning. A Wind
Advisory has been issued for portions of Maui County and Big
Island through 6 AM Thursday as a result. As the aforementioned
high continues to build, the pressure gradient tightens across the
state, and may cause more widespread and persistent winds to
exceed advisory thresholds briefly beyond the typical wind-prone
locations. The strongest winds are expected to continue through
tonight, then slowly weaken and become moderate to breezy by the
latter end of the week as the area of high pressure meanders
northeastward away from the islands.

As the week progresses, the enhanced trades will bring periods of
shower activity, particularly across windward and mauka areas.
Guidance continues to show an uptick in shower activity for today
as an area of moisture associated with a dissipating front gets
embedded in the trade wind flow, with much of the moisture aimed
at Maui and the Big Island. However, the latest model total
precipitable water (PWAT) normalized anomaly from the GFS and
ECWMF has seemingly toned down what was previously depicted 24
hours ago, highlighting PWAT values are closer to 0 to 1 standard
deviations above normal now. Despite this, expect windward trade
showers to be preeminent throughout the week, then gradually
lessen heading into the weekend.

Fall is in the air as a slightly drier air mass will keep dew
points mainly in the mid 60s, keeping the islands cooler than
average for the week. A few hours of lower relative humidity is
also once again possible late this morning as satellite
observations show a transient dry slot moving northeast to
southwest toward the state. This should be short- lived,
especially as the low- level moisture embedded in the trades moves
in shortly thereafter by this afternoon. Additional areas of
moisture should help to keep relative humidity values elevated
through the remainder of the week.

Some model guidance begins to depict a surface trough producing
southerly flow propagate over the islands escorting an abundance
of moisture from the tropics with it around Monday or Tuesday of
next week. Latest model guidance of the ECMWF and Canadian
retains the tropical moisture south of the islands. The GFS, on
the other hand, suggests ample moisture will be pulled northward
into the islands and leading to a potential heavy rainfall event.
The GFS also showcases a prolific cold front advancing southward
during the same time, which is not illustrated on the ECMWF or
Canadian. There`s still a fair bit of uncertainty, however,
namely given the long lead time before the event, and further
analysis on model trends will be required to determine how
accurate this initial assessment proves to be.


&&

.AVIATION...
Broad surface high pressure north of the island will lead to
breezy to locally windy trades persisting through Thursday
morning. Clouds and shower activity associated with these trades
will bring periods of MVFR/IFR conditions to windward and mauka
areas. Otherwise VFR conditions prevail.

AIRMET Sierra continues for mountain obscuration across all
islands.

AIRMET Tango will continue for mechanical turbulence over
and downwind of terrain below 8,000 feet

Both AIRMETs will likely remain in effect into Thursday.



&&

.MARINE...
A strong 1034 mb surface high, centered around 1000 nm north of
the islands, will help drive fresh to locally gale force trade
winds across Hawaiian waters this morning. The high will slowly
drift slowly southeast through tonight and maintain robust east
northeasterly flow. The strong trade winds, combined with building
northeast and northwest swells, will also result in seas greater
than 10 feet across the area. A Gale Warning remains in effect
through Thursday morning for the Alenuihaha Channel, where flow
funneling around the terrain of Maui and the Big Island will
accelerate trades even more. Elsewhere, a Small Craft Advisory
(SCA) remains in effect for a combination of winds and seas. The
aforementioned high to our north will gradually drift eastward and
weaken Friday into this weekend, allowing winds to weaken to
moderate to locally strong through this weekend.

The current short period northeasterly swell will produce large
breaking waves along east facing shores through Thursday
afternoon. A combination of higher than predicted water levels,
large breaking waves, and strong onshore winds could lead to
significant wave runup, beach erosion, and localized coastal
flooding for east facing shores during daily peak high tide cycle.
Thus, a High Surf Advisory remains in effect for east facing
shores through 6 PM HST Thursday. Northeast swell energy and
associated surf should decline late Thursday through this weekend
as local trade winds weaken.

A small to moderate, long period, northwest swell will peak later
today and keep surf along north and some west facing shores
elevated, but below advisory levels. This swell energy should
fade through Friday. Another small, long period, northwest swell
is progged to enter the local waters this weekend, which will
again bring a sub advisory level bump up of surf along north
facing beaches.

A small, long period, south swell will peak this morning and
generate surf near or slightly above the November average, then
fade through the remainder of the week.


&&

.FIRE WEATHER...
Breezy to windy trades will continue through early Thursday,
becoming moderate to breezy before the weekend. A few hours of
near critical fire weather conditions are possible late this
morning as relative humidity may briefly fall into the mid to
upper 40s due to a transient dry slot moving across the state.
However, this should be short-lived as low-level moisture
embedded in the trades quickly fills in behind. Additional areas
of moisture moving into the state should help to keep relative
humidity from reaching critical thresholds for the remainder of
the week. Temperature inversion heights near the Big Island and
Maui will range from 9,000 to 10,000 feet today.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 PM HST Thursday for Olomana-Maui
Windward West-Kauai East-East Honolulu-Koolau Windward-Molokai
Windward-Molokai Southeast-Windward Haleakala-Kipahulu-Big
Island East-Big Island North.

Wind Advisory until 6 AM HST Thursday for Lanai Mauka-Kahoolawe-
Maui Windward West-Maui Leeward West-Kohala-Big Island Interior-
Lanai Windward-Lanai Leeward-Maui Central Valley North-Maui
Central Valley South-South Haleakala-Big Island Southeast-Big
Island North.

Small Craft Advisory until 6 PM HST Thursday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters-Maui County Leeward Waters-Maalaea Bay-
Pailolo Channel-Big Island Windward Waters-Big Island Leeward
Waters-Big Island Southeast Waters.

Gale Warning until 6 AM HST Thursday for Alenuihaha Channel.


&&

$$


DISCUSSION...Pierce
AVIATION...Pierce
MARINE...JT
FIRE WEATHER...Pierce