735
FXHW60 PHFO 280600
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
800 PM HST Mon Jul 27 2026

.SYNOPSIS...

Moderate to breezy trade winds produced by strong high pressure
far northwest of the Hawaiian Islands will increasingly back
northeast ahead of an approaching Hurricane Fausto tonight into
Tuesday. Shower activity should also experience an uptick, but
continue to favor windward mountain areas through early Tuesday.
As Fausto passes north of the Hawaiian Islands on Tuesday and
Wednesday as a tropical storm, diminishing winds for the islands
could allow for sea breezes and heavy afternoon rain showers. A
drier, breezy trade wind weather pattern will return across the
state from Thursday onward as Fausto drifts westward away from the
Hawaiian Islands.

&&

.SHORT TERM UPDATE...

An increase in clouds and showers are occurring over the state.
Most of the showers are over and along windward and mauka
locations. Some showers are carrying over into leeward spots.
Both PoPs and Sky were adjusted to reflect this. No other changes
were made. It is important to note that Fausto is now a Tropical
Storm and will continue to weaken as it continues west-
northwestward.

&&

.PREV DISCUSSION...
Issued at 359 PM HST Mon Jul 27 2026

Satellite imagery and radar reveals bands of showers entering the
coastal waters from the northeast as increased moisture
associated with Hurricane Fausto begins to move into the Hawaiian
Islands. These showers will begin to move onshore this evening,
increasing precipitation for windward and mauka locations
through Tuesday morning. Total rainfall amounts could amount to
up to half an inch to one inch of rain for localized mauka areas.
Dew points are already increasing into the lower to mid 70s this
afternoon, which will make for muggy conditions through Wednesday
whilst Fausto passes north of the islands as a tropical storm.

Fausto`s passage to the north will also act to actually reduce
winds for the islands, which should allow for the development of
a sea breeze regime for the Big Island and possibly Maui County as
well on Tuesday. With the more saturated air, heavy rain showers
will be possible in the afternoon/evening for locations where the
synoptic-scale winds weaken enough to give way to the sea
breeze. Backed northeasterly trade winds are more likely to
persist ahead of the cyclone for Oahu and Kauai, which will keep a
more typical windward and mauka shower pattern.

Tuesday night, fairly weak winds and the potential for land
breezes should actually lead to more limited shower activity
despite the increased moisture and proximity of the tropical
storm. Southwesterly shear will tend to push the heavier
precipitation associated with the weakening storm north and east
of the center, away from Hawaii. On Wednesday, another day of
relatively weak winds will lead to further potential for sea
breezes and heavy rain showers, this time including Oahu and
Kauai.

At this stage, subtle shifts in forecast track may still occur
that would affect the specific island by island impacts from
Fausto. We strongly encourage the public to pay close attention
to this passing storm system as weather impacts over the Hawaiian
Islands will evolve the closer Fausto gets.

High confidence Fausto impacts include: warning-level high surf
warning for east facing shores through Tuesday. A High Surf
Warning is already in effect for east facing shores through
Wednesday. Lesser confidence impacts include: strong winds to
around 40 mph near and north of the low center and possible heavy
rain threats from Tuesday through Wednesday.

No time like the present to review your family hurricane preparedness
plans, and ensure every household has at least a 14 day supply of
food and water available if needed during this years active hurricane
season.

By Wednesday night, the cyclone continues on a west-
northwest track and begins to gain distance from the islands,
which will induce moderate to breezy southeast to easterly winds.
From Thursday onward, a drier and more stable breezy trade wind
pattern is set to return.

&&

.AVIATION...

This evening, numerous low clouds and showers are moving into
north through east sections of all islands. Latest surface
observations and satellite imagery show widespread MVFR ceilings
and visibilities, with isolated IFR conditions. As a result,
AIRMET Sierra has been issued for mountain obscuration
for windward sections of all islands. This AIRMET will likely
remain in place throughout the night. Should IFR conditions become
a bit more widespread, this AIRMET may need to be upgraded.

Meanwhile, as Tropical Storm Fausto draws closer (but remains
north of the islands), trade winds will weaken and become more
northeasterly tonight and Tuesday over the eastern end of the
state, followed Oahu and Kauai Tuesday night. As light southeast
to south winds will develop and spread over the state from east
to west, sea-breeze induced showers will increase. MVFR or
isolated IRF conditions are possible in heavier showers, but
otherwise, VFR flight conditions are expected to prevail.
Aviation interests near the Hawaiian Islands should monitor
updates to TC SIGMET Sierra, which covers Fausto, as the system
passes north of the islands over the next few days.

&&

.MARINE...

Moderate to fresh NNE winds will be in place tonight as Hurricane
Fausto enters the far northeast offshore waters. Winds will
become more north and decrease tonight into Tuesday as Fausto
moves through the northeast and northern offshore waters. As
Fausto passes by, winds will be light and variable over the
coastal waters, followed by south, then southeast immediately in
its wake. As Fausto moves off to the northwest and high pressure
builds to the north, east- northeast trades will build back in on
Thursday then strengthen to fresh to locally strong levels on
Friday into the weekend. A Small Craft Advisory (SCA) remains in
effect for the winder waters and channels around Maui County and
the Big Island through the remainder of the afternoon.
Additionally a SCA is now in effect for the windward waters due to
the east swell through Tuesday night.

Nearshore buoys on the eastern side of the islands have shown a
considerable uptick with the medium and long period energy from
Fausto. The surf is expected to continue building through the
evening and then peak tomorrow before dropping off Wednesday
afternoon. A High Surf Warning for east facing shores is currently
in effect through Wednesday afternoon. East shore surf will then
trend back up Friday into the weekend due to a combination of
rising trade wind swell and a new long period east swell generated
by Hurricane Genevieve.

A series of south swells will keep south shore surf near the
summertime average (5-6ft) through the week.

Surf along N shores could also see some brief increase as Fausto
(or its remnants) pass near the region Tuesday and Wednesday, then
return to typical flat to tiny levels late Wednesday into the
weekend.

&&

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

Small Craft Advisory until 6 AM HST Wednesday for Alenuihaha
Channel-Big Island Southeast Waters-Big Island Windward Waters-
Kaiwi Channel-Kauai Northwest Waters-Kauai Windward Waters-Maui
County Windward Waters-Oahu Windward Waters-Pailolo Channel.

&&

$$

UPDATE...Walsh
DISCUSSION...Quesada
AVIATION...Vaughan
MARINE...Foster