057
FXHW60 PHFO 050137
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
337 PM HST Fri Jul 4 2025

.SYNOPSIS...
Stable trade winds will will become breezy and gusty Saturday
through at least Tuesday as strong high pressure develops far
north of the state. Modest showers will be focused along windward
slopes, and aside from afternoon showers over the Kona slopes of
the Big Island, leeward areas will be mostly dry.

&&

.DISCUSSION...
Somewhat typical early July conditions prevail across the state,
though slightly wetter on Oahu and Maui County. Broad surface high
pressure far north of the islands continues to drive moderate to
locally breezy trade winds, and a building ridge aloft has pushed
the inversion down to 6,000 to 6,500 ft. A shallow and diffuse
band of moisture moving within this stable trade wind flow has
kept conditions somewhat cloudy on Oahu and Maui County, where up
to a quarter of an inch of rainfall was measured on windward
slopes today, and a narrow band of high clouds has also been
focused over the central portion of the island chain. Rainfall and
cloud cover has been less extensive on Kauai and Big Island,
though some afternoon showers are expected along the South Kona
slopes. No big changes are due tonight, with rain chances
diminishing on leeward Big Island.

Trade winds will become breezy on Saturday, and the stable, gusty
and rather dry conditions will persist through at least Tuesday.
Trades will increase as surface high pressure far northeast of
Hawaii strengthens to around 1032 mb. A mid level ridge will
continue to build overhead and push the inversion to as low as
5,000 feet. The interaction of the breezy trade wind flow with
the islands should generate wind gusts around 40 mph over and
downwind of terrain, though isolated areas on the Big Island and
Maui County could approach Wind Advisory criteria at times.
Guidance shows no distinct organized areas of moisture as
precipitable water stays below seasonal average. This should
result in modest windward rainfall and aside from scattered
afternoon and evening showers on the Kona slopes of the Big
Island, dry leeward conditions. See the Fire Weather section below
for additional discussion. A slight decrease in trade winds is
expected Wednesday.

&&

.AVIATION...
Breezy easterly trade winds will become gusty this weekend as
high pressure strengthens far northeast of the state. A fairly
stable environment will keep only brief passing showers in the
forecast, favoring windward and mountain areas. VFR flight
conditions will prevail for most locations, though brief MVFR
ceilings and visibilities will be possible within any showers that
pass through.

AIRMET Tango remains in effect for moderate low-level turbulence
over and downwind of island terrain. This AIRMET will likely
persist into early next week as gusty trades continue.


&&

.MARINE...
High pressure north of the islands will continue to strengthen
over the weekend and linger into next week. Strong trade winds
will develop by Saturday and continue through the beginning of
next week. The current Small Craft Advisory remains in effect
for most waters through Sunday afternoon. This will likely get
extended into next week and could get expanded to cover the
remaining waters. The high will weaken slightly by the middle
of next week causing trades to marginally decrease into the
breezy to locally strong range for the latter half of the week.

Surf for south facing shores will gradually fall below the
summertime average over the weekend as the current S swell
subsides. Tiny, long-period S swells will then hold into next
week until a new small, long-period swell fills in by Tuesday
night. This new swell could boost surf heights near the
summertime average (5 ft) by the middle of next week.

Surf for east facing shores will increase this weekend and become
rough and choppy as trade wind speeds increase. Surf along north
and west facing showers will remain small.

&&

.FIRE WEATHER...
Breezy, gusty, and rather dry conditions will develop on Saturday
and persist into early next week. Relative humidity at lower
leeward elevations will likely fall to around 45 percent each
afternoon, and with the inversion dropping to as low as 5,000 feet
winds will become gusty over and downwind of terrain. This will
result in near critical fire weather conditions over dry leeward
areas at times, though no headlines (watches or warnings) are due
since the Keetch Byram Drought Index will remain below the 600
threshold at Honolulu.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Sunday for Kauai Northwest
Waters-Kauai Leeward Waters-Kauai Channel-Oahu Leeward Waters-
Kaiwi Channel-Maui County Windward Waters-Maui County Leeward
Waters-Maalaea Bay-Pailolo Channel-Alenuihaha Channel-Big Island
Leeward Waters-Big Island Southeast Waters.

&&

$$

DISCUSSION...Wroe
AVIATION...Ahue
MARINE...Vaughan
FIRE WEATHER...Wroe