726
FXHW60 PHFO 092024
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
1024 AM HST Sun Mar 9 2025

.SYNOPSIS...
Showery remnants of a dissipating cold front will slowly spread
down the chain today, tonight, and Monday before moving away
Monday night. Most of the showers will favor Oahu today, Maui
County tonight, and windward Big Island on Monday. Other areas
will have cloudy periods and a few showers as well. High pressure
north of the islands will maintain locally windy trade winds into
the middle of the week. Winds will ease a little during the
second half of the week as the high moves closer to the islands.

&&

.DISCUSSION...
A 110 mile-wide band of broken showery cumulus extends over
portions of Kauai and Oahu this morning. This showery cloud band
is slowly sagging to the south, along the trailing end of a cold
front over the east Pacific. There are less organized and more
spotty showers out ahead of this band embedded within the trade
winds, mainlky to the east of the Big Island. Breezy to locally
windy trades are being driven by a large, springlike 1032 mb high
N of the state.

High resolution model guidance shows this showery cloud band
continuing to sag slowly south through the the next day or two.
The focus of this band should be on Oahu today, then expand to
include Maui County as well tonight as the band becomes more
diffuse and spreads out. One or two of the showers could come down
briefly heavy over windward and mauka areas, but there`s not much
upper support for anything more than that. According to the model
consensus, windward Big Island should start to see an increase in
showery weather before daybreak on Mon. On Mon the airmass will
start to dry out over the northern main islands with fewer showers
and quite a bit more sunshine returning on the still gusty
trades. Windward Big Island will remain pretty showery, however,
as the last of the deeper moisture gets hung up over the volcano
slopes. The more usual spotty trade wind showers will return to
the northern and central islands by Mon night.

The highh resolution guidance shows that as the drier air behind
the boundary spreads in, trade winds will surge once again and
there`s some possibility that portions of leeward Maui, or
leeward Kohala on the Big Island, could reach Wind Advisory
criteria. Will take another look at that and may need to consider
an advisory for those areas if confidence increases.

Looks like a fairly breezy week as a new surface high over the
North Pacific merges with the current high and sets up shop well
to our NNE. The winds will start to ease late in the week as the
high weakens and stretches out into a subtropical ridge by next
weekend. A fairly typical shower distribution is expected for much
of the week with the inversion hanging out near 6-7 thousand feet.
The usual light to moderate trade showers will favor nights and
mornings, and mainly over windward and mauka areas. Trade showers
will generally be a little more prevalent windward Big Island,
where slightly deeper moisture will lie, than for the smaller
islands. Otherwise, fairly nice, albeit gusty, trade wind weather
for much of the week. Easterly winds may start to get a little
more ESE and lighter by next weekend as a system develops well NW
of our islands.

&&

.AVIATION...
Breezy to locally strong trade winds will persist over the next
several days. Remnant moisture from a dissipated frontal boundary
will shift southward over the islands today. Brief MVFR ceilings
and visibilities are likely in showers, but VFR conditions are
expected to prevail through at least early evening. Shower
activity will further increase this evening, especially along
windward slopes and coasts. Mountain obscuration could become an
issue overnight for northeast facing slopes of the Big Island or
Maui late tonight or Monday morning.

AIRMET TANGO remains in effect for moderate low-level turbulence
over and downwind of island terrain. This AIRMET is expected to
continue over the next several days.

&&

.MARINE...
Persistent strong high pressure centered far north of Hawaii will
maintain a very tight pressure gradient between itself and lower
equatorial pressure, resulting in an extended period of fresh to
locally strong trade winds. As the airmass dries out behind a
remnant boundary over the next couple of days, the inversion will
lower, resulting in stronger and gusty winds with gale-force speeds
possible over the typically windier waters and channels surrounding
Maui County and Big Island later Monday through Thursday. The Small
Craft Advisory in effect for all Hawaiian waters will remain in
effect for the next several days for the strong winds and resulting
rough seas.

Yesterday`s northwest (310-330 degree) swell is veering more north-
northwest and lowering this morning, with surf now below advisory
level. This swell will progressively decline through the day. A
slightly smaller, medium-period north-northwest (330 degree) swell
will arrive around mid-week, with a reinforcing longer-period swell
on its heels to close out the week.

Rough surf will continue along east facing shores through the coming
week in response to the persistent strong trade fetch over and
upstream of the islands. East shore surf could become more elevated
and rough around the middle of the week as trades strengthen further.

Surf along south-facing shores will remain small, aside from the
possibility of some wrap from the easterly wind waves making it
into the more eastern-facing southern exposures.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Tuesday for all Hawaiian
waters-

&&

$$

DISCUSSION...R Ballard
AVIATION...Bedal
MARINE...TS