434
FXHW60 PHFO 301333
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
333 AM HST Tue Jun 30 2026

.SYNOPSIS...
Moderate to locally breezy trade winds will continue through the
weekend. Bands of low clouds and showers will be carried in on the
trades, focused primarily over windward and mauka areas during
the overnight and early morning hours. An enhanced area of
moisture is expected to reach the islands Tuesday night through
Wednesday, bringing more widespread showers. Humidity levels will
rise, bringing muggier conditions across the island chain through
the middle of this week. Additional areas of increased low level
moisture are possible this weekend.

&&

.DISCUSSION...
Radar and satellite show partly to mostly cloudy skies but only
isolated light showers as of 3 AM HST. The few showers detected by
radar were over windward areas, mainly on Big Island. Clouds were
a mixture of low level trade wind cumulus moving in from the east
and high-level cirrus associated with the subtropical jet moving
in from the west-southwest. Winds were averaging 5 to 15 mph
sustained, with gusts generally 15 to 20 mph.

An upper level ridge will remain generally north of the state
(centered around 40N) for the coming week as it slowly drifts
west. At the same time, an area of surface high pressure will also
remain north of the state around the same latitude, and it will
also drift west with time. Trades will continue through the
period, with showers mainly windward and mauka, and more numerous
at night.

One significant area of increased low level moisture will move
in from the east tonight and Wednesday, spreading more numerous
showers to windward and mauka areas, and increasing the chance for
noticeable spillover to leeward areas. Brief heavy rain is
possible, but the risk for flooding is low. Surface dewpoints will
increase into the lower 70s as this moist area moves through,
then drop back into the mid to upper 60s from Wednesday night into
the weekend.

All of this was already in the forecast, and changes have been
minimal in this latest package.

&&

.AVIATION...
A brief break between passing low level troughs will produce
mostly VFR conditions across the Hawaiian Islands through this
afternoon. The next trough, slightly weaker than the last system,
moves westward through the islands tonight through Wednesday.
Expect increasing shower trends with brief periods of MVFR
conditions and mountain obscurations, mainly along windward
mountain areas.

AIRMET Sierra remains in effect for mountain obscuration along
north and east slopes of Maui and the Big Island. This AIRMET will
diminish in coverage later this morning, a few hours after
sunrise.

&&

.MARINE...
A surface high pressure will remain centered well north of the
Hawaiian Islands this week and help drive moderate to fresh trades
trades across the region. A Small Craft Advisory (SCA) is in
effect for the typical windy waters around Maui County and the Big
Island. The SCA advisory will likely need to be extended for
these areas through much of this week with the persistent trades.

The long-period south swell we had is slowly fading and will
continue to decline leading to decreasing south and west shore
surf through Wednesday. A small bump in surf along south- facing
shores is possible Thursday into Friday with the arrival of a
small, long-period south swell, but another larger long-period
south swell energy pulse should arrive by late Saturday.

Surf along east-facing shores will remain rough and choppy through
the week with moderate to fresh trades in place. Nearly flat surf
heights will persist along north facing shores.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST this evening for Alenuihaha
Channel-Big Island Leeward Waters-Big Island Southeast Waters-
Maalaea Bay-Pailolo Channel.


&&

$$

DISCUSSION...Parker
AVIATION...Bohlin
MARINE...Walsh