677
FXHW60 PHFO 071949
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
949 AM HST Fri Jun 7 2024

.SYNOPSIS...

Light to gentle easterly trade winds will develop today as a ridge
meanders just north of Kauai. Over the weekend the ridge will
lift northward, allowing trade winds to gradually strengthen.
Moderate to locally breezy trade wind conditions are expected by
Sunday, and persist into the middle of the new week. Very stable
conditions will greatly limit shower activity through the weekend,
with a slight increase in windward showers expected Monday and
Tuesday. A more typical trade wind pattern should return by the
middle of next week.

&&

.DISCUSSION...

This morning visible satellite image shows a shallow cloud deck
riding in with gentle easterly trade winds over the Big Island
with some clouds forming along windward areas of the smaller
islands. Leeward locations are generally sunny except for leeward
Big Island where sea breezes have developed and clouds are moving
in along the coast. Expect some clouds to build up along other
leeward coast and interior areas through the afternoon as
sea breezes continue to develop under this hybrid trade wind and
land/seabreeze wind regime. Based on this morning soundings,
inversion heights remain abnormally low around 3 kft. Chances of
rainfall will remain low as very stable conditions persist.

The ridge will begin to lift northward over the weekend, which
will allow the trades to gradually return from south to north.
Moderate to locally breezy conditions are expected by Sunday and
persist into the middle of next week. Clouds and showers will
return to the more typical windward and mauka areas, however
shower activity will remain limited across the entire state over
the weekend due to very stable conditions from low inversion
heights. The trade wind inversion will begin to lift early next
week, which should bring a slight increase in trade wind showers
Monday and Tuesday, but will still remain drier than normal for
this time of year. A more typical trade wind pattern should return
during the middle to latter half of the week with rising
inversion heights.

&&

.AVIATION...

A weak pressure gradient across the region will maintain light
trade winds across the state with daytime sea breezes developing
by mid morning especially over the leeward areas. Shower activity
will continue to remain limited due to a strong ridge of high
pressure aloft. A few light showers will be possible during the
afternoon mainly over interior and leeward areas and the Kona
slopes of the Big Island. With the strong inversion, ceilings will
be quite low with any clouds, which will allow for periods of MVFR
conditions.

AIRMET Sierra is in effect for tempo mountain obscuration for
leeward sections of the Big Island and windward Oahu. These
conditions should generally improve by around mid day as the sea
breezes develop.

&&

.MARINE...
A weak elongated ridge in the northern offshore waters will hold
in place over the region. Expect wind speeds to remain below Small
Craft Advisory (SCA) threshold through Saturday. High pressure
will redevelop north of the state over the weekend, allowing
moderate trade winds to build back. Models show the potential for
SCA conditions across typical windier waters around Maui County
and the Big Island by Sunday.

The current south-southwest swell will peak today and steadily
decline through the weekend. That said, morning observations show
this swell is producing surf up to High Surf Advisory (HSA)
threshold along south facing shores, prompting issuance of an HSA
valid through tonight. A bigger moderate long period south-
southwest swell will build through Saturday, peak Sunday night
into Monday and could generate surf at or above HSA threshold
once again at the peak. Yet another long period south swell may
generate HSA threshold surf late next week.

The current small northwest swell continues to decline. However,
a reinforcing pulse from the northwest will build in late this
afternoon to give north facing shores a small bump. Wind waves
for east facing shores have diminished significantly and will
remain small into the weekend.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Saturday for all south facing
shores.


&&

$$


DISCUSSION...Almanza
AVIATION...Kino
MARINE...Powell