863
FXHW60 PHFO 050644
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
844 PM HST Tue Feb 4 2025

.SYNOPSIS...

Scattered showers will mainly focus along windward and mauka areas as
northeast winds veer easterly and weaken tonight through Thursday,
especially east of Kauai where a pool of moisture will linger.
Light easterly flow will allow for seabreezes to develop in the
afternoon allowing for clouds and showers to build over sheltered
leeward and interior areas each afternoon through Thursday. Land
breezes will develop overnight clearing clouds and showers.
Moderate trades with fair weather conditions will return Friday
into the weekend.

&&

.DISCUSSION...

Latest satellite imagery shows an broad area of shallow cumulus
clouds moving into parts of Oahu, Maui County and the Big Island,
with clear skies over Kauai. Radar shows numerous showers embedded
in this cloud field focusing mainly light showers along windward
and mauka areas of Oahu embedded in a northeasterly flow with
showers becoming more scattered east of this area. A slight
increase in intensity and coverage is expected this evening due
to cloud top cooling overnight and a broad mid level trough
continuing to erode low to mid level ridging. Latest High
Resolution Ensemble Forecast (HREF) remains on track, showing the
greatest shower coverage around Maui County and parts of windward
Big Island tonight as the northeast flow pushes this area of
moisture southwestward.

On Wednesday, a ridge of high pressure will approach the state from
the north and will cause the winds to veer more easterly and weaken.
Light trade winds will likely be overpowered by the developing sea
breezes during the middle of the day, which should allow for afternoon
clouds and some scattered showers to develop in sheltered leeward and
interior areas. Chances of showers will be greatest east of Kauai due
to a pool of lingering moisture. Another upper level short- wave trough
approaching the state late Wednesday, could enhance some of the showers
Wednesday evening into Thursday over Maui County and the Big Island.
This short-wave trough looks a little stronger and is carrying a little
more moisture in the upper levels than the current trough. Expect inversion
heights to have a better chance of eroding allowing for more vertical
development of clouds with light to locally moderate rainfall
rates Wednesday evening into Thursday.

Starting Friday, an upper level ridge will build overhead and a
surface high will build northeast of the state. This should allow
for stable trade wind weather to return and push any remaining
moisture west of the state. Overall, it looks like a dry trade
wind pattern Friday through Saturday, with a slight increase of
passing showers possible on Sunday.

Latest USGS report the Kilauea eruption has paused but volcanic
gas emissions may continue to impact nearby communities. With
winds expected to decrease tonight into Wednesday, any lingering
haze may spread around the Big Island. Chances of haze spreading
to Maui Wednesday into Thursday is a little uncertain but will
continue to monitor. Trades should return Friday into the
weekend pushing and remaining haze offshore.

&&

.AVIATION...
Light to moderate north-northeast trades will ease overnight, with
land breezes developing in some of the more sheltered areas. Winds
will become light statewide on Wednesday, allowing sea breezes to
develop in most areas. An area of enhanced moisture will keep some
showers and MVFR cigs/vsbys moving into windward areas tonight and
Wednesday morning, with improving conditions expected in most
areas by early afternoon.

AIRMET Sierra remains in effect for mountain obscuration for
windward sections of Oahu and Big Island. This AIRMET will likely
be expanded to include Molokai and Maui later tonight.

AIRMET Tango remains in effect for moderate upper level turb
across Maui County and the Big Island between FL200 and FL240.
SIGMET Xray covers an area of severe turb occurring across the
entire island chain between FL240 and FL360. Conditions will
gradually improve from west to east tonight, with the moderate or
greater turb area expected to shift east of the islands around
noon Wednesday.

&&

.MARINE...
Winds will gradually veer to the east and weaken into the gentle
to locally moderate range tonight through Thursday as a high
pressure system approaches the state. The ridge will lift
northward Friday through the weekend, which increase trade winds
back to moderate to locally strong Saturday afternoon through the
forecast period. A Small Craft Advisory for winds will be likely
for the windier waters and channels around Maui County and the Big
Island by Sunday.

Overlapping northeast and northwest swells will continue to
impact the state tonight. The High Surf Advisory for exposed north
and east facing shores, as well the Small Craft Advisory in
exposed coastal water zones and the Marine Weather Statement for
Kahului and Hilo harbor surges have all been extended through the
night given buoy observations, with these highlights likely
dropping by morning. The northeast swell will slowly drop off
Wednesday, but a reinforcing northeast swell is expected around
Thursday, which could elevate surf along east facing shores near
advisory thresholds. A long period northwest swell is expected to
fill in late Thursday and peak on Friday near High Surf Advisory
thresholds.

Surf along east facing shores should continue to see moderate
surf with the swell. Surf along south facing shores will remain
tiny through the forecast period with mainly background energy.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Wednesday for Niihau-Oahu
North Shore-Olomana-Maui Windward West-Kauai North-Kauai East-
East Honolulu-Koolau Windward-Molokai Windward-Molokai Southeast-
Molokai North-Maui Central Valley North-Windward Haleakala-
Kipahulu-Big Island East-Big Island North.

Small Craft Advisory until 6 AM HST Wednesday for Kauai
Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-
Kauai Channel-Oahu Windward Waters-Kaiwi Channel-Maui County
Windward Waters-Alenuihaha Channel-Big Island Windward Waters.


&&

$$


DISCUSSION...Almanza
AVIATION...Jelsema
MARINE...Shigesato