501
FXHW60 PHFO 060126
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
326 PM HST Tue Aug 5 2025

.SYNOPSIS...
Trade winds will weaken to land and sea breezes by Wednesday as
remnant of former Tropical Cyclone Gil passes just north of the
state through Wednesday night. Humidity, cloud cover and showers
will increase through Thursday, and will repeat Sunday through
Monday as Henriette passes to the north.

&&

.DISCUSSION...
Former Tropical Cyclone Gil, currently centered 430 miles
northeast of Hilo, will open to a trough as it passes north of
state on Wednesday. Winds will weaken this evening to where
nighttime land breezes and daytime sea breezes dominate through
the following 24 hours.

Gil remnants will bring cloud cover and very humid air mass
across the state. While most of the trough of what is left of Gil
will pass to the north, moisture along the southern fringes will
get caught in Wednesday`s sea breeze flow and allow for interior
clouds with scattered showers to set up for all islands in the
afternoon. Some showers could become briefly moderate-heavy
intensity. The trough will move west of the area Wednesday night
with some lingering clouds and showers expected around the area
Thursday.

Drier conditions return briefly with moderate trade winds on
Friday and Saturday. Long range global models currently show
another weakening tropical system, currently Tropical Storm
Henriette in the East Pacific, will pass north of the islands
from Sunday through Monday, once again disrupting trade winds with
land and sea breezes, along with warm and very humid conditions.

&&

.AVIATION...
Light to moderate trade winds today will diminish further tonight
into tomorrow morning as a trough drifts just north of the area.
Land and sea breezes can be expected tomorrow and an influx of
moisture from the trough could allow for increased cloud and
shower coverage. Due to the nature of the sea breezes, the highest
cloud and shower chances look to come tomorrow afternoon for
interior and leeward areas as well as the slopes of the Big
Island. VFR conditions will be most prevalent with MVFR
conditions in the showers.

No AIRMETs in effect and none are expected until tomorrow where
AIRMET Sierra for mountain obscurations will be possible.

&&

.MARINE...
Moderate to fresh northeasterly trade winds will weaken tonight
and Wednesday as a surface trough passes north of the islands.
Trade winds will strengthen and become more easterly on Thursday
as the trough moves northwest of Kauai, and a Small Craft
Advisory (SCA) will likely be needed for the typically windy
waters near Maui County and the Big Island Thursday and Friday.
High pressure far northeast of the state will drift to the north
over the weekend as Tropical Storm Henriette nears the region from
the east, and local winds are expected to decline below SCA
strength by Saturday. Henriette will be near or north of the
islands by Sunday.

An extended run of south swell will continue this week. During its
peak last night and this morning, the current swell produced surf
at the High Surf Advisory (HSA) threshold, and this swell will
continue to slowly decline through Wednesday. Long-period
forerunners from the next south-southwest swell will build late
Wednesday, and during the Thursday peak of the swell, south shore
surf should remain below the HSA threshold. A larger south swell
will build Friday through Saturday, generating surf well above the
HSA threshold, and possibly near the High Surf Warning level,
into Sunday. This swell will gradually decline early next week.

Even as wind wave energy declines with the easing trades, east
shore surf will be elevated through Wednesday due to east swell
produced by former Tropical Cyclone Gil. Windward PacIOOS buoys
have been registering swell of around 3 feet at 13 seconds today,
and guidance suggests that the swell may rise as high as 5 or 6
feet tonight as the period drops to 11 or 12 seconds. This may be
enough energy to produce HSA level surf along east facing shores
into Wednesday morning. Due to a lack of confidence in the rising
swell, we have opted to hold off on issuing a HSA for now but will
monitor the buoys tonight. The swell will decline rapidly late
Wednesday and Thursday as strengthening trades generate near
seasonal average wind waves. As waves decline over the weekend,
east swell from East Pacific Tropical Storm Henriette may arrive.

A very small northwest swell originating from a former West
Pacific typhoon is producing tiny surf along north shores. Another
tiny northwest swell is scheduled to arrive late Wednesday into
Thursday, preventing north shore surf from going completely flat.

&&

.FIRE WEATHER...
Trades will diminish tonight while humidity levels increase as a
tide of tropical moisture sweeps into the islands as the remnants
of former Tropical Cyclone Gil drifts westward and passes just
north of the Hawaiian Islands on Wednesday. Another round of deep
tropical moisture will sweep through the islands from Sunday into
Monday as Henriette follows a similar path.

&&

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


&&

$$


DISCUSSION/FIRE WEATHER...Foster
AVIATION...Tsamous
MARINE...Wroe