261 
FXHW60 PHFO 250135
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
335 PM HST Wed Sep 24 2025

.SYNOPSIS...
A cold front will move over Kauai overnight bringing widespread 
showers and a slight chance of thunderstorms Thursday into Friday.
Weakening trades will allow land and sea breezes over the rest of
the state to bring afternoon interior showers. Additional showers
and thunderstorms may trigger on the Big Island Friday and Saturday
afternoons. Trades and more stable weather move in Sunday.

&&

.DISCUSSION...
Trade winds are weakening across Hawaii this afternoon in response
to a low pressure system approaching from the northeast. The
associated cold front is moving quickly southwest towards our 
area, and should reach the western end of the state after midnight
tonight, and expect an increase in clouds and showers as the low
level moisture moves in. A low aloft is positioned near 30N150W
that will also track southwest and bring in colder air aloft that
will destabilize the atmosphere across the western end of the 
state Thursday into Friday. The moisture and instability maximizes
just north of Kauai and will bring the potential for some heavier
showers and a slight chance of thunderstorms. 

The front will weaken to a trough as it gets wound up by a
developing surface low along the front. Winds will shift southerly
as this feature sets up, but speeds will be light allowing
localized sea breezes by Thursday afternoon that will focus clouds
and shower over interiors of all islands. Widespread showers
should surround Kauai through the day into Thursday night with 
Oahu along the southern edge of the shower band. Shower coverage
will become a bit more diffuse Friday into Saturday across the
smaller islands, but could fire up again along island interiors 
in the afternoons. Meanwhile, the southerly flow will bring 
deeper tropical moisture over the Big Island, potentially 
triggering showers and thunderstorms Friday and Saturday 
afternoons.

The low pressure system north of the island chain will begin to
drift westward away from the Hawaiian Islands from Sunday into
Monday. This change in the weather pattern will allow the broad
ridge north of the region to build in allowing more stable trade 
wind weather to return to the islands by next week Tuesday and 
Wednesday. Expect moderate to locally breezy trade winds along 
with brief passing showers during this time period, favoring the 
windward mountain areas in the overnight to early morning hours.

&&

.AVIATION...
Trade winds will diminish into light and variable land and sea 
breezes tonight as a weak frontal boundary nears Kauai overnight.
The front will stall and weaken to a trough generating clouds and
showers near the island of Kauai Thursday and Friday. Showers may
be heavy at times with periods of MVFR conditions. Isolated 
thunderstorms are possible.

No AIRMETs are currently in effect.

&&

.MARINE...
Trade winds will weaken today in response to a low pressure system
to the north with an associated cold front stretching into the 
northern offshore waters. The front and low will move south, and 
the front is expected to weaken into a trough and could stall in 
between Kauai and Oahu tomorrow afternoon. Winds will become 
light and southerly tonight into tomorrow with the exception of 
the northwestern waters of Kauai where northeasterly winds are 
still expected until Friday. By Friday and Saturday, light
southerly winds are expected statewide before trade winds build
back in by Sunday in response to a high pressure ridge moving in.
Trade winds can then be expected early next week.

A close proximity low pressure system to the north with northerly
winds pointed towards the islands will send a moderate medium 
period N-NNE swell to N facing shores tonight and peak tomorrow 
afternoon. There is also a small NW swell that will be filling in 
tomorrow through the weekend helping to keep surf heights slightly
elevated. A small medium period NW swell is then expected to fill
in Monday and decline slowly through next week. Tiny to small 
background N and NW pules will keep north shores from going 
completely flat for the remainder of next week.

Surf for south facing shores will remain small through tomorrow
before a small long period south swell arrives on Friday and peaks
over the weekend at or slightly above the September average (5 ft).

Surf for east facing shores will stay small today then will likely 
see an increase from the N-NNE swell tomorrow and Friday. The 
islands to see the greatest increase would be Kauai and Oahu, as 
these islands are most directly within the fetch area of the low 
to the north. This swell will fade out by the weekend. Trade wind
chop could increase by Sunday as trade winds return.

&&

.FIRE WEATHER...
Forecast trend towards both weakening winds and higher humidity
across the state through the weekend. Critical fire thresholds
are not expected over the next several days. Moderate trade winds
and drier conditions expected by next week. Weak, elevated
inversion around 7-9 kft today should erode and disappear Thurs

Temperature inversion heights near Maui and the Big Island today 
will range from 6,000 to 7,000 feet elevation.

&&

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

&&

$$


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