381
FXHW60 PHFO 301927
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
927 AM HST Thu Jul 30 2026

.SYNOPSIS...

Remnant low Fausto will continue to shift far northwest of the
area today. A strong high will build in from the north allowing
trade winds to strengthen from east to west across the state today
reaching breezy levels by this afternoon and evening. Trades will
further strengthen Friday into Saturday under a dry and stable
airmass that could produce very windy downsloping winds that may
warrant a Wind Advisory. Trades will ease back to the usual breezy
levels Sunday into early next week as the high weakens. Typical
summertime showers are expected for windward and mountain areas.

&&

.SHORT TERM UPDATE...
A band of widely scattered light to moderate showers, associated
with the remnant of Fausto, is quickly becoming diffused over the
Kauai Channel, with the heavier showers well north of Kauai. A
hybrid pattern of seabreezes and light to breezy southeast winds
could increase chances of clouds and showers over interior and
upslope mountain ranges later this morning and early afternoon for
the western half of the state. Otherwise, breezy easterly trade
winds will push a shallow deck of clouds and with embedded light
to moderate showers over the Big Island and Maui County through
the morning hours and the rest of the state this afternoon,
leading to a more typical summertime trade wind pattern by this
evening.


&&

.PREV DISCUSSION...
Issued at 346 AM HST Thu Jul 30 2026
A band of light to moderate showers will transit through the
western half of the state this morning as the remnant circulation
and moisture of Fausto exits the area to the west. East to
southeast winds can still be expected for Oahu and Kauai for the
morning before the typical breezy easterly trade winds fill in
during the afternoon. Showers then will focus over the usual
windward and mountain areas through the weekend and next week.

Trade winds are then forecast to ramp up Friday and Saturday to
strong levels as high pressure to the north strengthens. Model
cross sections show the inversion staying around 5,000 ft and mid
level temperatures increasing. These factors will increase the
chances of strong downsloping winds under an increasingly stable
airmass, and could get to wind advisory levels. A wind advisory
for parts of the state is being considered and more details will
follow as confidence increases. The time period for the strongest
winds at this time appears to be Friday night through Saturday
afternoon. Dewpoint temperatures are also forecast to decrease as
drier air moves in with the strengthening trades. The lower
humidity, decrease in showers, and increased winds will elevate
the fire weather threat. We will continue to monitor all available
guidance and observations.

Sunday into early next week trades will weaken to moderate to
locally breezy levels as Hurricane Genevieve tracks far northeast
of the state, disrupting the trade wind flow.

&&

.AVIATION...
Moderate to locally breezy trades will spread from east to west
across the island chain today as remnants of tropical cyclone
Fausto passes further to the northwest of the state. Meanwhile, an
area of enhanced low level moisture will bring clouds and showers
to mainly windward portions of Kauai through the morning hours.
Some MVFR ceilings and visibility in SHRA may accompany this band
as it moves over the Kauai. Trades will remain moderate to
locally breezy tonight with showers and clouds favoring windward
locations.

No AIRMETs are currently in effect as AIRMET SIERRA has been
cancelled early this morning. AIRMET TANGO will likely be issued
by this afternoon over and immediate S through W of the eastern
islands.


&&

.MARINE...
Issued at 346 AM HST Thu Jul 30 2026

Variable to light northerly winds will yield to east-southeast to
easterly trades building in from east to west across the state
today as Fausto`s remnant low exits off to the northwest. A Small
Craft Advisory (SCA) is in effect through Friday night for strong
trade winds throughout the windier waters of Maui County and the
Big Island. Trades strengthen through the weekend, which could
necessitate an expansion of the SCA to the rest of the coastal
waters later on. A weakness in the ridge of high pressure develops
on Sunday, which will cause trade winds to weaken again for early
next week.

A medium period south swell peaking today will bring south shore surf
around the summer average (5-6ft). Surf then fades gradually through
the weekend while a mix of small south swells maintains surf slightly
below the seasonal average.

Surf along east shores will trend up tonight into the weekend due to
a combination of building short period trade wind swell and renewed
medium to long period east swell emanating from Hurricane Genevieve
in the East Pacific. North shores will see flat to tiny surf through
early next week as a weakening Post-Tropical Cyclone Fausto moves
away from the islands and no significant north swells are
forecast.

&&

.FIRE WEATHER...
Issued at 346 AM HST Thu Jul 30 2026

Trade winds are expected to strengthen from east to west across
the state Thursday becoming breezy to locally strong Friday into
Saturday. As the winds become strong late Friday into Saturday, a
drier more stable airmass will filter in, increasing the
potential for locally strong downsloping winds. While KBDI will
remain below the critical thresholds there could still be some
fire weather concerns.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Saturday for Alenuihaha
Channel-Big Island Leeward Waters-Big Island Southeast Waters-
Maalaea Bay-Pailolo Channel.


&&

$$

SHORT TERM UPDATE...Almanza
DISCUSSION/FIRE WEATHER...Tsamous
AVIATION...Shigesato MARINE...Quesada