Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 05/09/2026 11:13:00 PM UTC

                        
307
FXHW60 PHFO 091313
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
313 AM HST Sat May 9 2026

.SYNOPSIS...

A weak surface trough will gradually move east to west across the
islands through tonight, resulting in light winds and land/sea
breeze showers. As this trough dissipates, trades will build in
stronger through Monday. Trades will be on the increase Tuesday
onward.

&&

.DISCUSSION...

Windward and mauka showers with some limited spillover to leeward
areas are ongoing across the island chain. Satellite indicates
low clouds over or near the higher terrain on each island, along
with high clouds streaming in from the southwest.

A weak surface trough near Maui will slowly drift westward,
reaching Kauai on Sunday. Trade winds will build in behind this
trough from east to west through the weekend. Wind speeds will
initially be light to moderate, but will become moderate to
locally breezy into early next week. This trough will keep winds
weak enough to allow for land/sea-breeze showers to occasionally
develop over leeward areas, even as trade winds build in and bring
their typical windward and mauka focused showers.

While that is occurring at the surface, the flow aloft will change
significantly. We will transition from weak troughing to our
north this weekend to the rapid development of a closed ridge to
our northwest by Monday. This ridge will become elongated along an
east-west axis and remain with us all next week. Its presence
will keep a surface ridge in place, allowing the trades to blow at
least through the end of next week, and likely longer. This means
mainly windward and mauka showers will hang around. There will be
occasional fluctuations in available moisture throughout this
period, and these will result in periods of enhanced shower
activity from time to time.

&&

.AVIATION...

Light to moderate trades gradually return tonight, becoming
locally breezy today and persisting through the next several
days. Expect cloud and shower activity to develop along the
typical windward and mauka areas, resulting in periods of MVFR
conditions. Otherwise, VFR conditions will prevail.

AIRMET Sierra remains in effect for mountain obscuration over
much of the state due to lingering showers.

There may be the need for AIRMET Tango for low-level turbulence
as trades gradually return.

&&

.MARINE...

A high pressure ridge will remain in place north of the islands
with gentle to fresh trade winds for most coastal waters with
periods of strong trade winds developing over the windier waters
and channels near Maui and the Big Island from Sunday onward. A
Small Craft Advisory may be needed for these windier waters by
tonight or possibly by Sunday.

A declining medium period northwest swell and associated surf
heights along north and west facing shores will slowly fade
through the weekend. Small north-northwest medium period swell
energy will keep surf heights on the small side through the first
half of next week.

The current small south swell energy will fade through the weekend.
Small pulses of background long period swell energy will keep
surf heights along south facing shores above flat levels.

Surf along east facing shores will remain below normal this
weekend, but will gradually increase next week as trade winds
strengthen.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$


DISCUSSION...Walsh
AVIATION...Pierce
MARINE...Bohlin