423
FXHW60 PHFO 191352
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
352 AM HST Wed Nov 19 2025

.SYNOPSIS...

Breezy to locally windy trade winds will push deep tropical
moisture over the state today. Moderate to locally heavy rainfall
will possible mainly along windward and mauka areas of Maui and
the Big Island this morning before spreading to the other islands
this afternoon. The chance of heavy rainfall will diminish later
today, but breezy and showery trades will persist through
Thursday. Mid level drying will limit clouds and showers Friday
into early next week. Easing trade winds over the weekend could
allow for more of a hybrid land/sea breeze pattern over the
weekend. Drier moderate trades should return Sunday.


&&

.DISCUSSION...

So far overnight rainfall totals have been modest with most
rainfall located along windward and mauka areas of Kauai, Maui and
the Big Island ranging from .10 to .20 inches. An extensive cloud
deck and embedded showers which has remained mostly off the
eastern shores of the Big Island overnight and is now moving
onshore. Radar shows scattered moderate to locally heavy showers
moving along windward and mauka areas of Maui County and Big
Island. High resolution model guidance continues to show of
rainfall picking up through the morning hours as stronger trade
winds pushes a north to south orientated axis of moisture
westward. The main chance of locally heavy rainfall remains along
windward and mauka areas of Maui County and the Big Island. Some
locally heavy rainfall of 1-2 inches per hour could produce
nuisance flooding but so far showers have been very small and
brief. The threat for heavy rain will decrease later today as
upper level instability shifts north and west of the state. Winds
will near advisory levels for the windier areas of Maui County and
the Big Island a high builds north of the state.

Increasing thick clouds over the Big Island summits could briefly
produce light snow accumulations this morning as precipitation
increases, however the snow will quickly transition to rain after
sunrise. The Winter Weather Advisory currently runs through today
and could be extended through Thursday morning as the deep
moisture lingers and overnight temperatures dip to near freezing.

As for the rest of the state, scattered light to moderate showers
will mainly focus along the windward and mauka regions this
morning as trade wind speeds pick up. Inversion heights are
expected to increase throughout the day as the airmass becomes
more mixed, allowing showers to become more moderate and spilling
over to leeward areas at times. Locally heavy rainfall could be
possible later this afternoon into the evening hours.

The strong surface high passing north will maintain breezy trade
winds into Thursday. A band of low level clouds currently near
140W, is progged to move over the state during the day Thursday
keeping a rather cloudy and wet tradewind pattern in place.

Trade winds are expected to ease Friday into the weekend as a
front approaches the state from the far northwest. Mid level
drying should limit clouds and showers. A few high clouds may
remain as an upper level short wave trough passes north of the
state Friday. A hybrid trade wind and sea breeze pattern could
develop Saturday as winds relax allowing for clouds and showers to
develop along leeward and interior areas and low level moisture
from the dissipating front moves over the state. However, cloud
heights and showers will continue to be limited due to dry mid
levels. The greatest chance of showers will be around Big Island
where lingering moisture will be the deepest. Drier and more
stable conditions will fill in Sunday into early next week as mid
to upper level ridging builds over the state and moderate trades
return.


&&

.AVIATION...
Layered clouds moving S to N primarily over Big Island this
morning will cause light icing from FL140-FL260 as highlighted in
AIRMET ZULU. AIRMET Tango continues for moderate turbulence
between FL250 and FL400 over all islands. Tango will likely be
dropped by 2200Z as turbulence is expected to decrease through the
morning.

Trades will strengthen a bit today, becoming gusty and peaking
near 25 knots at more windward facing airfields. There is still a
slight chance for a windward AIRMET Sierra these next few hours
for mountain obscuration. Ceilings may lower to MVFR within
afternoon showers.


&&

.MARINE...

Moderate trade winds will increase over the next 12 hours. The
weakening front to the north is not expected to push much farther
east, and northeast winds are already increasing at NOAA buoy
51001 as strong surface high behind the front is starting to
exert influence. As the front dissipates and the surface high
moves north of the state today, expect trade winds to ramp up,
eventually reaching near gale strength in the Alenuihaha Channel.
A Small Craft Advisory (SCA) is in effect for the typical windy
waters around the Big Island and Maui and expands to cover all
waters at 6AM today through Thursday as trades rapidly build. The
high will be pushed to the east by a North Pacific front late
Thursday and Friday, leading to a gradual decline in the trades.
Trades may decline further this weekend as the front passes north
of the islands.

A northwest swell is moving in this morning and will gradually
increase surf along exposed north and west shores from Kauai to
Maui. A High Surf Advisory may be needed later today as the swell
shifts out of the north- northwest and continues to build. The
northwest swell will be accompanied by a small to moderate short
period north swell aimed primarily west of Kauai, while building
trades produce increased wind waves. The combined seas from all of
these sources will be in excess of 10 feet that will contribute
to the need for the SCA. The north- northwest swell will gradually
decline Thursday and Friday, with another northwest swell pushing
surf back near the advisory level Saturday.

East shore surf will be on the rise today and Thursday, primarily
from increased short period trade wind swell, though the western
end of the island chain could also experience a brief short period
north (350-010 degrees) swell of 3 to 6 feet at 10 seconds. As
mentioned above, this north swell will be primarily aimed west of
Kauai, but some wrapping energy could push east shores of Kauai
near the High Surf Advisory level later today. The north swell
will rapidly fade on Thursday, when peaking trade wind swell will
produce surf just below the advisory level on east shores of all
islands. East shore surf will decline through the weekend as
trades weaken over and upstream of the islands.

For south shores, tiny background south swell energy will
persist.


&&

.FIRE WEATHER...

Critical fire weather conditions not expected through the forecast
period. Periods of heavy rain remain possible over Maui County
and the Big Island through today. Gusty trades continue into
Thursday, with winds eases below critical thresholds thereafter.
Lingering moisture will keep relative humidities above critical
thresholds.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM HST this evening for Big
Island Summits.

Small Craft Advisory from 6 AM this morning to 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-Big Island Windward Waters.

Small Craft Advisory until 6 PM HST Thursday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.


&&

$$


DISCUSSION...Almanza
AVIATION...Blood
MARINE...Walsh
FIRE WEATHER...Almanza