Haiku-Pauwela, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

343
FXHW60 PHFO 060645
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
845 PM HST Sat Oct 5 2024

.SYNOPSIS...

Gentle to moderate trade winds will continue for the rest of the
weekend, bringing a few showers to windward areas. Additionally,
afternoon sea breezes will bring clouds and showers to leeward and
interior areas. A low aloft will destabilize the island
atmosphere, supporting locally heavy showers and a slight chance
of thunderstorms, first for Kauai and Oahu (including surrounding
waters) tonight, then spreading to the remainder of the state
Sunday. Stronger trade winds and increasingly stable conditions
will return next week.

&&

.DISCUSSION...

Forecast remains on track with gentle to moderate trade persisting
across the state through Sunday. Latest satellite and radar
imagery show mostly scattered light to brief locally heavy
showers mainly along windward and mauka locations. Some light to
moderate showers from earlier this afternoon are starting to taper
off as we head into the evening hours and land breezes develop.
Most of the heavier more persistent showers remain over leeward
coastal waters where convergence is more prevalent. For the rest
of the evening expect more of a tradewind flow pattern with
clouds and showers mainly focusing along windward and mauka
areas. The afternoon sounding shows the inversion height around
Kauai has increased to around 10 kft from 7 kft early Saturday
morning. This will allow more windward clouds and showers to spill
over to leeward areas overnight and in the early morning hours
with some showers being heavy at times and a slight chance of
thunderstorms for Kauai and Oahu tonight.

The forecast remains on track for Sunday with the low aloft
shifting southward and eventually settling over the central
islands. This will allow for further destabilization over the rest
of the state. Thus expect inversion heights to increase around
Maui County and the Big Island allowing for enhanced clouds and
showers and slight chance of thunderstorms. Winds are expected to
remain light enough for leeward seabreezes to develop in the
afternoon, and could provide enough lift to produce a showers
along leeward and inland areas as well as a slight chance of
thunderstorms. As we head into the evening hours expect more a
tradewind pattern to take over as land breezes develop and likely
chances of heavier showers to shift more towards windward areas
during the overnight and early Monday morning hours.

The caveat to the forecast, is the lack of a deep moist profile
that will allow for more widespread showers and convection.
Therefore, although there should be sufficient moisture for a few
heavier showers and perhaps isolated thunderstorms, the amount of
moisture and dry layer between 700 and 500mb maybe the limiting
factor.

Models still show trade winds gradually increasing as early as
late Sunday into early next week as a new high pressure to the
distant northwest builds eastward. Instability may linger through
Monday, but generally, increasingly stable trade wind conditions
should return by Tuesday and persist through much of next week as
the upper low weakens into a broad trough and shifts east of the
state. With the return of a more typical trade wind pattern,
expect clouds and showers to favor primarily windward and mauka
areas.


&&

.AVIATION...
Moderate trade winds will continue this weekend with afternoon
sea breezes developing over terrain sheltered leeward areas. An
upper level low moving over the islands today will increase low
cloud and shower trends through at least Sunday. MVFR with brief
IFR conditions this weekend will favor windward and mountain
areas, including converging sea breeze boundaries along the
leeward slopes. There remains a slight chance of thunderstorms
over the state through the weekend.

No AIRMETs are currently in effect.


&&

.MARINE...
A weakened ridge to the northeast of the islands is driving
gentle to moderate trades across the region this evening. An upper
low has moved into the offshore waters to the northeast of the
islands. Models show this upper low will strengthen as is sinks
southward over the next 24 hours. A chance for thunderstorms
remains in the forecast for the offshore and coastal waters near
the upper low through tomorrow afternoon. By tomorrow night, the
low is forecast to lift back to the north. A ridge is rebuilding
to the north of the islands and this will help strengthen trades
cross the region. By Monday morning, Small Craft Advisory (SCA)
level winds are possible in the typical windier coastal waters
near Maui County and the Big Island. Once SCA winds return, we can
expect those to continue through at least mid- week.

A pair of overlapping small, short period north swells should
maintain small surf across north facing shores through the
remainder of the weekend. A short lived small, short to medium
period northeast swell is expected through tomorrow, which will
also boost surf along east facing shores. There is the potential
for a moderate long period north-northwest swell as early as
tomorrow, which would peak Monday below advisory levels for north
facing shores, with the swell lingering into the middle of the
new week. A moderate, long period south swell should arrive
tonight. Expect this to then fill in tonight, peaking perhaps a
little later tomorrow, hold into Monday, and then gradually
decline through the middle of next week. This swell may boost surf
along south facing shores to near or slightly below advisory
levels during its peak.


&&

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

&&

$$


DISCUSSION...Almanza
AVIATION...Bohlin
MARINE...Powell