867
FXHW60 PHFO 221302
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
302 AM HST Sat Jun 22 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 later today and Sunday.

&&

.DISCUSSION...
Breezy, gusty, and somewhat wet conditions are in place early
this morning. A 1030 mb surface high sitting about 900 miles
north of the state is driving the breezy trade winds, and a mid-
level ridge is maintaining stability. This will keep the gusty
trade wind flow just below Wind Advisory strength. A band of
shallow moisture moving along the trade wind flow has dropped more
than a half of an inch of rainfall across many windward areas in
the past 12 hours, though the onset of showers on windward Big
Island has been a bit delayed. Expect the wet conditions to linger
into the morning from Kauai to Maui, where periodic showers will
blow over leeward areas, followed by drier weather in the
afternoon. Windward Big Island will remain wet through the day,
and likely into the evening, while showers develop along the Kona
slopes in the afternoon.

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 as a disturbance aloft approaches
late next week.

&&

.AVIATION...
Breezy to locally windy trades will continue across the region
through Monday. 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. Decreasing shower trends are forecast to start after 10 AM
HST.

AIRMET Sierra remains in effect for tempo mountain obscuration
for north and east slopes of Kauai, Oahu, Molokai, and Maui.
Including the entire island of Lanai and eastern slopes of the Big
Island. This AIRMET will diminish in coverage around noon HST.

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 Monday.

&&

.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 continue to trend up 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 several 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 Monday for all Hawaiian
waters.

&&

$$

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