010
FXHW60 PHFO 220627
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
827 PM HST Fri Jun 21 2024

.SYNOPSIS...
High pressure far north of the islands will maintain breezy and
gusty trade winds through early next week. Somewhat wet conditions
will give way to a more typical pattern of passing windward
showers by Saturday afternoon.

&&

.DISCUSSION...
Breezy, gusty, and somewhat wet conditions are in place this
evening. A 1030 mb surface high anchored about 900 miles north of
the state is driving the breezy trade winds, and a mid-level ridge
is maintaining stable conditions that are helping to produce wind
gusts just below Wind Advisory strength over and downwind of
terrain. Shallow moisture moving along the trade wind flow is
producing somewhat wet conditions from Kauai to Maui this evening.
The moisture will spread down to the Big Island overnight, and
there should be quite a few windward sites on all islands that
puck up between a half and one inch of rainfall through Saturday
morning. Some of these showers will be periodically carried over
leeward areas.

The gusty trades will persist on Saturday nearly unchanged,
meaning some areas across the Big Island and Maui County will
register winds near or just below the advisory level. All islands
except the Big Island will experience a decrease in shower
activity as moisture within the trade wind flow diminishes.

The strong surface high will remain anchored north of the state
Sunday through at least Monday, maintaining the breezy and gusty
trade winds near current strength. A stable and rather typical
summertime rainfall pattern will prevail, leading to modest
rainfall over windward slopes. Aside from afternoon showers on the
Kona slopes of the Big Island, leeward areas will be mostly dry.

Trades will decline to moderate strength around Tuesday or
Wednesday as the high to the north finally weakens. Some increase
in showers will be possible late next week.

&&

.AVIATION...
Breezy to locally windy trades will continue across the region
for the next few days. A band of clouds drifting in on the trade
winds will bring showers with periods of MVFR conditions to
windward mountain slopes of each island at least through the
early morning hours.

AIRMET Sierra remains in effect for tempo mountain obscuration
for north and east slopes of Kauai, Oahu, Molokai, and Maui. This
AIRMET will likely expand to the Big Island later tonight.

AIRMET Tango remains in effect for mod low level turb over and
downwind of island terrain due to the breezy trade winds. This
AIRMET will likely continue through the weekend.

&&

.MARINE...
Strong easterly trades will continue into early next week,
supporting the Small Craft Advisory in place for all waters. Seas
will remain rough, with heights hovering around and just under
the advisory level over exposed waters. Guidance shows a slight
downward trend Tuesday through midweek due to the surface ridge
potentially weakening to the north.

Surf along east-facing shores will remain rough through early
next week due to the aforementioned strong trades locally and
upstream of the state. A gradual downward trend is possible
Tuesday through midweek.

Surf along south-facing shores will trend up slightly this
weekend as a small south swell moves through. This should be
short-lived, with a downward trend expected early next week.
Despite a blocking high that has set up over our typical swell
window near/southeast of New Zealand, a gale has formed to its
northeast with the head of the fetch aimed at the islands within
the 180 to 200-degree directional band. Given the shorter travel
distance, surf associated with this source should trend up late
next week.

Surf along north-facing shores could trend up above flat levels
early next week due to a small, medium-period northwest swell from
a marginal gale lifting northeastward near the Aleutians. On its
heels is a compact storm-force low, currently a few hundred
nautical miles east of Japan, that could send a similar northwest
swell through the area late next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Sunday for all Hawaiian
waters.

&&

$$

DISCUSSION...Wroe
AVIATION...Bohlin
MARINE...Gibbs