Waianae, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

393
FXHW60 PHFO 190111
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
311 PM HST Thu Jun 18 2026

.SYNOPSIS...
A weak surface trough and its associated moisture plume over the
western end of the state will shift northwest through Friday,
bringing a slight uptick in shower activity as it passes through.
Otherwise, a lighter background flow will allow for a sea/land
breeze pattern to persist into the weekend with showers developing
over leeward and interior areas each afternoon, followed by
clearing at night. Then trade winds will gradually strengthen
through next week, shifting the shower focus to windward and mauka
areas.

&&

.DISCUSSION...
Radar and visible satellite imagery show a slightly veered east-
southeast flow steering clouds and isolated showers parallel to
the island chain this afternoon. The bulk of the clouds and
showers are remaining just east of the state and along a weakly
convergent boundary associated with the weak surface trough near
Kauai, but clouds and a few showers have also managed to develop
over leeward and interior areas of each island with the afternoon
sea breezes.

The surface trough will weaken further and gradually shift
northwest of the state through Friday, with moderate east-
southeast winds filling in behind it through Saturday. Winds will
briefly take on an east-northeasterly tilt on Sunday as a
front/trough approaches from the northwest. With wind speeds
gradually strengthening, a mix of windward and mauka showers with
isolated afternoon sea breeze leeward and interior showers can be
expected through the weekend. In addition, dew points are expected
to remain in the 70s for many locations through Saturday,
maintaining muggy conditions through much of the weekend.

Heading into next week, the subtropical high to the far northeast
will regain control and easterly trades will build to moderate to
breezy levels through midweek. This will usher in slightly lower
dew points, and combined with the breezier trades, some relief
from the mugginess. Model guidance suggests that an upper level
low will pinch off of the longwave trough to the far north and
approach the state from the northeast mid to late-week, possibly
providing some enhancement to windward and mauka showers as
batches of moisture move through.

&&

.AVIATION...
Gentle to moderate east to east-southeast trade winds continue to
push a weak surface trough and associated shallow moisture over
the islands. The enhanced low-level moisture has been producing
areas of lower than normal MVFR ceilings across windward slopes
of Oahu and Maui County, where AIRMET Sierra for mountain
obscuration remains in place. Afternoon sea breezes have produced
low clouds and isolated showers across interior and leeward
terrain, but this activity has been somewhat suppressed by
continued stable conditions. Expect improvement over leeward areas
this evening and less extensive MVFR ceilings over windward areas
on Friday.

&&

.MARINE...
Light to moderate trades will hold for the next few days as a
weak surface ridge remains to the north and a broad surface trough
continues to move west over the island chain the next few days.
The weak trough is currently located between Oahu and Kauai waters
and is producing some scattered showers over the coastal and
offshore waters. Scattered showers will generally decrease over
the coastal waters by Friday. Trades may increase slightly over
the weekend as the trough dissipates, with more pronounced
strengthening early next week as the ridge strengthens to the
north.

A moderate, long period south swell is peaking at advisory levels
this afternoon, thus a High Surf Advisory remains in effect for
all south facing shores through early Friday morning. This swell
should drop below advisory levels by Friday as the swell gradually
fades late tonight into the weekend. A series of smaller south-
southwest swells will fill in Sunday into the first half of next
week and will maintain surf near seasonal averages through next
week.

Tiny surf will prevail on north and east shores through most of
the coming week. A slight increase in east shore surf is expected
around next Tuesday or Wednesday as trade winds build across the
region.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Friday for Big Island South-
Big Island Southeast-East Honolulu-Ewa Plain-Honolulu Metro-
Kahoolawe-Kauai South-Kauai Southwest-Kona-Lanai Leeward-Lanai
South-Maui Central Valley South-Maui Leeward West-Molokai
Leeward South-Niihau-South Haleakala-South Maui/Upcountry-
Waianae Coast.

&&

$$

DISCUSSION...Farris
AVIATION...Wroe
MARINE...Almanza