Lahaina, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

043
FXHW60 PHFO 040704
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
904 PM HST Tue Dec 3 2024

.SYNOPSIS...
Mostly dry and stable conditions will prevail through Wednesday,
with a wetter trend possible Wednesday night through the second half
of the week as a front approaches and moves into the area. Light
south to southeast winds will gradually increase as the front nears
Wednesday night into Thursday, especially over the western end of
the state. The front will stall and begin to diminish over or around
Oahu Thursday night into Friday. Breezy north-northeast winds will
fill in behind it Thursday and Thursday night over the western end
of the state, with a brief return of trades Friday. A second front
passing north of the area over the weekend could lead to the trades
weakening again.

&&

.DISCUSSION...
Dry and stable conditions with a deep layer ridge in place over
the state will linger into Wednesday, with the land and sea
breeze regime continuing. A transition period is anticipated
later Wednesday through Thursday as upper heights begin to lower
in response to a shortwave trough digging southward into the
area. Expect increasing southerly winds and lift ahead of the
attendant cold front approaching and moving into the area, that
could lead to a few pre-frontal showers as early as Wednesday
afternoon for the western end of the state. The better dynamics
(40 to 45 kt 0-6 km shear) and upper height falls are expected
Wednesday night over and around Kauai, then potentially for Oahu
through the day Thursday as the front nears Kauai. Although
chances are low, a thunderstorm or two can`t be completely ruled
out, especially over the adjacent waters of Kauai Wednesday night.

A weakening trend is anticipated Thursday night into Friday as
the shortwave trough begins to lift northeastward and away from
the area. Guidance depicts the frontal boundary stalling around
Oahu through this time and slowly diminishing Friday. Expect
breezy north to north-northeast winds trailing the front Thursday
and Thursday night over the western end of the state, before
veering out of the east on Friday. A return of light trades is
possible over the weekend as another front passes to the north.

&&

.AVIATION...
Light to occasionally variable winds out of the southerly
quadrant persist. Sea/land breezes should continue through
tomorrow. Any SHRA and low cigs will be brief. While some isol
MVFR conds are possible in SHRA, VFR should prevail through the
forecast period. A

No AIRMETs in effect.

AMD NOT SKED in at PHJR and PHMK for equipment issues, with no
estimated time for repair.

&&

.MARINE...
An E-W oriented surface ridge extending over the islands from the
E is supporting gentle winds statewide that are out of the E-SE
over Big Island waters, and from the S-SW over Kauai and Oahu
waters. Little overall change in the ridge`s position is expected
through Wednesday. A low passing N of the islands late Wednesday
and Thursday will force the ridge eastward, with a tightening
low-level gradient supporting fresh to locally strong S to SW
winds statewide as an associated front approaches from the NW.
Fairly high confidence in the front moving over Kauai on Thursday,
then stalling near Oahu from late Thursday into Friday. Winds
and/or seas will likely reach Small Craft Advisory (SCA) criteria
in at least some of the waters Thursday and Friday.

As the front stalls and dissipates, locally fresh post-frontal N
winds over Kauai and Oahu will gradually ease and veer to the NE
Thursday night into Friday, while light to moderate E winds will
prevail over Maui and Big Island waters. Wind speeds will quickly
diminish statewide on Saturday, then light ENE trade winds on
Sunday are expected to strengthen next week as high pressure
builds to the distant NE.

Long fetches of near-gale to gale-force winds associated with
low pressure systems passing well N of the area will send NW
swell of varying sizes and periods toward the islands this week.
Most of the swell energy will be in the shorter-period 12-14
second bands, with resultant surf expected to be near or above
High Surf Advisory (HSA) levels along exposed N and W facing
shores into the weekend.

In the short term, significant wave heights at NDBC buoys
51001/51101 NW of Kauai remain elevated at 10 to 12 feet, but the
longer period energy present last night and this morning has
diminished. A High Surf Advisory (HSA) remains posted for exposed
N and W facing shores overnight, and while surf heights will
remain elevated on Wednesday, peak heights are likely to diminish
below HSA levels. Another NW swell Thursday into Friday will
likely produce HSA-level surf, with a smaller NNW pulse possible
next weekend.

A long-period S swell is currently producing surf near the summertime
average along S facing shores, and will gradually decline through
Thursday. Another long-period S swell is expected by this weekend,
but it will likely be a little smaller than the current swell.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Wednesday for Niihau-Kauai
Leeward-Waianae Coast-Oahu North Shore-Maui Windward West-Kauai
North-Molokai Windward-Molokai North-Molokai West-Windward
Haleakala.

&&

$$

DISCUSSION...Gibbs
AVIATION...Walsh
MARINE...Birchard