553
FXHW60 PHFO 301346
AFDHFO

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

.SYNOPSIS...

As the remnants of Fausto exit the region today, trade winds will
increase to breezy levels this afternoon, then strong to locally
windy levels Friday and Saturday. Trades then ease back to the
usual breezy levels early next week as the high weakens. Typical
summertime showers are expected for windward and mountain areas.

&&

.DISCUSSION...
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 former 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 Oahu and Kauai. Some MVFR ceilings and
visibility in SHRA may accompany this band as it moves westward
over the region. Trades will remain moderate to locally breezy
tonight with showers and clouds once again favoring windward
locations.

AIRMET SIERRA remains in effect for north through east sections of
Oahu above 2000 ft due the passing showers and low clouds.
AIRMET TANGO will likely be needed by the end of the day as
breezier trades fill in.


&&

.MARINE...

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...

Trade winds will to strengthen today becoming strong Friday into
Saturday. Coinciding with the strong winds, a drier and more
stable airmass is forecast to arrive, increasing the potential
for locally strong downsloping winds. While KBDI will remain below
the critical thresholds, the other factors (wind and mid 40s
relative humidities), could increase the fire weather concerns.


&&

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


&&

$$


DISCUSSION...Tsamous
AVIATION...Thomas
MARINE...Quesada
FIRE WEATHER...Tsamous