852
FXHW60 PHFO 140106
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
306 PM HST Sun Sep 13 2026

.SYNOPSIS...
Relatively dry and weak trades will gradually strengthen through
Wednesday, then become moderate through next weekend. Moisture
from the remains of Norbert should arrive Thursday into Friday,
greatly increasing shower coverage and intensity. Drier air will
move back in next weekend as trades continue.

&&

.DISCUSSION...
Radar and satellite show isolated showers, mainly over Kauai
County. Clouds were building over Big Island, where one or two
showers were seen over higher terrain. Winds remain relatively
light in most areas, averaging 10 to 15 mph with higher gusts.

An upper level "high over low" block in the to our northeast will
keep the upper level pattern rather stable through the coming
week. At the surface, a large high pressure system centered near
45N 145W through Wednesday. This will keep us in a trade wind
pattern, with wind speeds increasing Wednesday and remaining
moderate through next Sunday. Moisture from the remains of
Norbert are forecast to move through the area Thursday and Friday,
and we have increased PoPs through that period. PW values are
still forecast to get up to near 2 inches. Just about the time
that moisture arrives, the trades will back slightly and become
easterly. A slight turn back to ENE winds looks likely late next
weekend. Except for the increased chance of showers Thu/Fri, it
should be a relatively dry week for most folks.

&&

.AVIATION...
The forecast remains on track as lighter and drier trade winds
hold over the Hawaiian Islands this afternoon. Shower activity
should remain limited today 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. The trade winds are
generally weak to moderate this afternoon, though winds may become
light enough within more wind- protected leeward areas to
initiate local topographically- driven breezes. The forecast looks
to be close to a rinse and repeat for tomorrow.

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.

There is currently one AIRMET in effect for Kauai for mountain
obscuration due to clouds around 025, which should end later this
evening. No additional AIRMETs are likely, but we`ll continue to
keep an eye out at reports and webcams should the reach mountain
obscuration criteria for clouds and/or precip.

&&

.MARINE...
Moderate trades will continue through the week before gradually
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 to the coastal waters
Tuesday into Wednesday. While the current forecast has Tropical
Storm Norbert dissipating before it nears the Hawaiian coastal
waters from the east, remnant moisture from this system is
expected to arrive potentially by Thursday, likely bringing more
showers.

Surf along south-facing shores will gradually decline through Monday
as the small, medium-period energy slowly fades. A series of
long-period swells are expected during the second half of the
week. The first pulse will gradually fill in Tuesday into
Wednesday out of the southwest, followed by larger south-southwest
swells Friday into the weekend. Surf could get near advisory
thresholds over the weekend, but at this time it looks like it
would peak just below advisory thresholds.

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

&&

.FIRE WEATHER...
Fire weather risk will remain low the next several days due to
light to moderate winds and the effects of recent rainfall.
Inversion heights should be 6000 to 7000 ft through Monday.
Moisture increases Thu/Fri, and should bring enough showers to
keep things relatively wet.

&&

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

&&

$$

DISCUSSION/FIRE WEATHER...Parker
AVIATION...KR
MARINE...Foster

NWS HFO Office Area Forecast Discussion