650
FXHW60 PHFO 180144
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
344 PM HST Mon Aug 17 2026

.SYNOPSIS...
Light showers are possible through this evening. Trade wind
pattern returns Tuesday with windward and mauka showers much of
this week. Precipitation chances increase Friday and Saturday for
windward areas. Winds may veer southeasterly late in the week.

&&

.DISCUSSION...

Scattered, light showers will diminish this evening. Over the past
12 hours an additional 0.20 to 0.60 inches of rain has fallen across
the state, with some locally higher accumulations. For the middle of
the week, the atmosphere will gradually dry out in the wake of
Tropical Storm Lala. Moderate strength winds will prevail for the
first half of the week, becoming light by Thursday. The return of
the trade winds will maintain scattered showers over windward and
mauka locations, with isolated spill over into leeward areas.

For late Thursday through the weekend the trades will veer east-
southeast, pulling additional moisture into the area. This will
increase precipitable water values for Friday and Saturday. Due to
the expected moisture increase, precipitation chances have been
increased for Friday into Saturday, especially for windward areas. A
subtle drying is expected on Sunday.

For early next week, there is quiet a bit of difference between
the GFS and the ECMWF. The GFS supports a wetter pattern with the
ECMWF on the drier side. Current forecast maintains drier
conditions, which may need adjusting in the coming days depending
on how the pattern develops.

&&

.AVIATION...

A ridge of high pressure north of the state will maintain breezy
easterly trades through Tuesday. Lingering moisture from Tropical
Cyclone Lala continues to produce low/mid-level clouds over the
eastern half of the state. Light to moderate showers focused over
windward and mauka slopes are generating localized MVFR
conditions, with VFR elsewhere. Shower coverage will increase
overnight for windward and mauka areas before drier, typical trade
wind conditions return Tuesday.

AIRMET Sierra remains in effect for mountain obscurations along
windward portions of Kauai Oahu and the Big Island, as well the kona
slopes of the Big Island due to sea breezes. AIRMET Sierra may
need to be expanded to other islands overnight into Tuesday
morning as windward and mauka showers increase.


&&

.MARINE...

With Tropical Storm Lala now well west of the islands, fresh to
locally strong easterly trade winds have prevailed across the
region today. A Small Craft Advisory (SCA) remains in effect for
the windier waters and channels around Maui County and the Big
Island through tonight, but trade winds will gradually ease
dropping into the moderate to locally breezy range by Tuesday.
During the second half of the week, trades will weaken further to
become light and variable for most waters before strengthening
again this weekend.

Surf along south facing shores remains elevated from a moderate,
medium to long period swell that filled in last night.
Observations at PacIOOS buoy Barber`s Point shows the south swell
maintaining at roughly 4 feet, 14 seconds this afternoon. Based on
the buoy readings and surf observations from lifeguards and
webcams around the state, have adjusted south shore surf up
slightly from the previous forecast for this evening. However, it
is still expected to slowly decline through midweek, so the
overall trend remains unchanged. Some wrap also continues this
evening for west facing shores, but this is also expected to
follow suit as the south swell declines. Another long period south
swell generated from gales just south and east of New Zealand
will begin arriving late this week.

Surf along east facing shores will continue to fade tonight as
Lala moves further west away from the state and as trades decrease
on Tuesday. North facing shores will remain tiny throughout the
week.


&&

.FIRE WEATHER...
Issued at 339 PM HST Mon Aug 17 2026
Moderate relatively moist trade winds will prevail through
mid-week. Winds will weaken Thursday and Friday with increasing humidity.
Trade winds increase over the weekend with minor changes in humidity.
No fire weather concerns through the forecast period.
There is no temperature inversion.

&&

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


&&

$$

DISCUSSION/FIRE WEATHER...CO
AVIATION...Almanza
MARINE...Vaughan