Waipahu, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

746
FXHW60 PHFO 281924
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
924 AM HST Sun Jun 28 2026

.SYNOPSIS...
Trade winds will ease slightly today, then remain at mostly
moderate speeds through the rest of the week. Bands of low clouds
and showers will periodically push across the islands, focusing
primarily over windward and mountain areas during the overnight
and early morning hours. A couple bands of enhanced moisture will
move through the islands tonight through Thursday morning,
bringing an increase in shower coverage and intensity, with some
locally heavy rainfall possible. In addition, humidity levels will
rise, making the first half of the work week feel rather muggy
across the island chain.

&&

.SHORT TERM UPDATE...
High pressure to the far northeast of the state will drive
moderate to locally breezy trades across the state today. Radar
and satellite imagery show low clouds and mostly isolated showers
filtering into windward and mauka areas with this mid morning
update. More notably, a plume of moisture associated with a weak
disturbance can be seen just east of the Big Island. As this
feature continues to progress westward, it will bring an uptick in
windward showers to the Big Island and Maui later this afternoon
or evening, then spread up rest of the island chain through
Monday. While widespread flooding issues are not expected, some
of these showers are expected to be heavy at times, which may lead
to isolated minor flooding concerns for windward and mauka areas.

&&

.PREV DISCUSSION...
Issued at 300 AM HST Sun Jun 28 2026
Currently at the surface, a 1035 mb high is centered around 1700
miles north-northeast of Honolulu, driving moderate trade winds
across the island chain early this morning. Infrared satellite
imagery shows mostly cloudy conditions in windward and mauka areas,
with partly cloudy skies prevailing in most leeward locales. Radar
imagery shows scattered showers moving into windward slopes and
coasts, with a few showers spilling over to leeward communities at
times. Main short term focus revolves around trade wind trends
and rain chances.

High pressure will meander north and northeast of state during the
next 7 days, keeping trade winds solidly in place through the
period. Moderate to locally breezy trades tonight, will ease
slightly on Sunday, then remain at mostly moderate speeds Monday
through late next week.

As for the remaining weather details, fairly typical summertime
trade wind weather is expected through the period, with showers
favoring windward and mauka areas, particularly during the night
and early morning hours. A couple bands of enhanced moisture
will affect the state during the first half of the week however.
The first batch of enhanced moisture is evident in satellite
imagery near 150W or about 250 miles east of the Big Island. This
band of moisture is expected to ramp up shower coverage and
intensity as it moves from east to west across the islands tonight
through Monday evening. The next area of enhanced moisture
currently close to 140W or about 950 miles east-northeast of the
state, is forecast to move through the islands Tuesday night
through early Thursday, increasing shower coverage and intensity
once again.

Both these bands will raise precipitable water values into the
1.5 to 2.0 inch range and elevate inversion heights to between 10
and 12 kft. Some locally heavy rainfall can`t be ruled out as
these bands of moisture move through, particularly the second
batch of moisture affecting the islands during the middle of the
week. That said, with the trades in place, a widespread flash
flood threat is not expected, but some minor flooding could very
well necessitate flood advisories during this time. Additionally,
dewpoints are forecast to increase to around 70 or the lower 70s
beginning Monday and continuing through the middle of the week,
making it feel more muggy across the island chain.

&&

.AVIATION...
Moderate to locally breezy trades are expected through Monday.
Low clouds and scattered showers will move over primarily
windward and mauka areas, making for intermittent MVFR
conditions. Otherwise VFR conditions are expected.

A small area of low pressure is approaching Big Island this
afternoon and may increase shower coverage and strength from
roughly 3 PM HST to midnight.

AIRMET Tango is in effect for moderate turbulence downwind of
terrain due to breezy trade winds and will continue through the
forecast period.

&&

.MARINE...
Issued at 300 AM HST Sun Jun 28 2026
A high pressure ridge far north of the Hawaiian Islands will
remain anchored in place, keeping trade winds blowing across the
region through much of this week. The Small Craft Advisory (SCA)
remains in effect through this afternoon for the typical windier
waters near Maui and the Big Island.

The current small, long period south swell will peak today, before
gradually declining over the next few days. Another larger south
swell energy pulse will arrive next weekend.

Surf along east facing shores will remain rough and choppy with a
slight decline possible early in the week as trade winds weaken
slightly. Surf heights along north facing shores will remain
nearly flat.

&&

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

&&

$$

SHORT TERM UPDATE...Farris
DISCUSSION...Jelsema
AVIATION...Parker
MARINE...Bohlin