213
FXHW60 PHFO 141403
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
403 AM HST Mon Sep 14 2026

.SYNOPSIS...
An increase of moisture from the remnants of Norbert will bring a
wet trade wind pattern from late Wednesday through Friday. Deep
tropical moisture combined with some instability will bring an
increase of heavy rain especially over windward and mauka areas.
In areas that see less rainfall such as leeward areas, hot and
muggy conditions are expected by the middle of the week. Improving
weather conditions are generally expected over next weekend, but
some scattered showers will likely persist.

&&

.DISCUSSION...
This morning`s satellite imagery shows a band of moisture east of
the Big Island, which will be moving east to west across the
state today. 12Z soundings from Lihue and Hilo show a stable
trade wind inversion at around 5000 to 6500 ft. While stable
conditions are expected to persist over the next few days, the
increase of moisture will bring an increase of humidity and some
light to moderate showers over windward and mountain areas.
Dewpoints are expected to get into the 70s by late Monday into
Tuesday, which will bring some muggy weather across the state.

Starting Wednesday and continuing through Friday, the weather
pattern will change as the remnants of Norbert moves east to west
across the state. Deep tropical moisture from Norbert combined
with a weak upper level trough will bring an increase of heavy
showers especially by Thursday. With trades picking up to moderate
to breezy speeds by late Wednesday into Thursday, the focus of the
heavy rain will be over windward and mauka areas. A Flood Watch
may be warranted especially for Thursday into Thursday night, but
we will wait to see what the high res models show as we get closer
to the second half of the week. So overall we are expecting a wet,
trade wind pattern during the second half of the week with the
focus of the heavier showers over windward and mauka areas. While
leeward areas should see some frequent showers, in areas with less
shower activity can expect hot and muggy weather, with dewpoints
getting up into the mid 70s.

Over the weekend, while the bulk of the deep tropical moisture
should move west of the state, showery weather could linger
through at least parts of Saturday. But generally improving
weather conditions are expected this weekend with moderate to
breezy trade winds.


&&

.AVIATION...

A few light showers have developed tonight, and are drifting over
the islands tonight from Kaua`i to Maui, with MVFR conditions
possible in showers. Showers should be short-lived, with no
significant mountain obscuration expected at this time, however
will need to The forecast remains on track with drier trade winds
for the Hawaiian Islands tonight into tomorrow. Expecting shower
activity to remain limited through tomorrow thanks to these winds,
with the windward side of the islands having a 15-40% chance for
showers while the rest of the areas remain dry. Trade winds for
tomorrow look similar in strength, perhaps a touch lighter, and
that should allow for sea breezes to develop on the leeward side
of the islands.

For PMDY conditions look to remain dry, though we may get a few
low to mid level clouds due to a low sitting north of the region.
Opted to keep the forecast dry for the site on Monday, though the
ECMWF model shows the potential for some passing showers Monday
afternoon. Both the GFS and the ECMWF show showers late Monday
into Tuesday, with winds shifting to the north or northwest.

For NSTU, models show passing showers through the TAF cycle,
which may bring periods of MVFR cigs and vis.



&&

.MARINE...
Moderate to locally fresh trades will continue through Tuesday before
strengthening through the latter half of the week. Moisture
associated with a weak trough moving in on the trade wind flow may
bring a slight uptick in shower activity today into Tuesday.
Wednesday night, the remnants of Tropical Storm Norbert enter the
offshore waters and are forecast to bring a more significant
increase in moisture and stronger trade winds Thursday into the
weekend.

Surf along south-facing shores will be slightly below seasonal average
through Tuesday. A series of long-period swells are expected during
the second half of the week. The first pulse will gradually fill in
tonight into Wednesday out of the southwest, followed by larger
south-southwest swells Friday into the weekend. Surf gradually trends
upward through the week beginning Wednesday and will approach
advisory thresholds by the weekend.

Surf along east-facing shores should see an increase during the
second half of the week as the trades strengthen and the remnants
of Tropical Storm Norbert move through the islands. Flat to tiny surf
along north facing shores is expected through the forecast period.


&&

.FIRE WEATHER...
Issued at 328 AM HST Mon Sep 14 2026

Fire weather risk will remain low throughout this week due to
light to moderate trade winds the next few days followed by a wet
trade wind pattern during the second half of the week. Inversion
heights should be around 5000 to 7000 ft through Tuesday due to
stable conditions.


&&

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

&&

$$

DISCUSSION/FIRE WEATHER...Kino
AVIATION...LP
MARINE...Quesada