243
FXHW60 PHFO 210151
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
351 PM HST Thu Nov 20 2025

.SYNOPSIS...
A breezy and somewhat wet trade wind flow will prevail into
Thursday morning, followed by a gradual decline in winds and
shower activity late Friday. Trade winds will decline to light to
moderate strength as high clouds thin during the weekend, and
while showers will favor windward slopes, a few afternoons shower
will be possible over leeward terrain on Saturday. A stable
moderate trade wind flow is expected Sunday through early next
week.

&&

.DISCUSSION...
Breezy trade winds persist this afternoon, and a band of shower-
bearing low clouds can be observed just off the windward coasts of
most islands underneath a shroud of layered high clouds. A 1031 mb
surface high is centered roughly 1300 miles northeast of Hawaii is
driving the gusty trades, while a persistent upper level trough
centered just to the west and northwest continues to send layered
high clouds over the state. Shower activity has been subdued this
afternoon over all islands except windward Kauai, as the low
level flow has dried slightly ahead of a band of moisture
lingering just east of the islands.

Shower activity is expected to pick up tonight and linger into
Friday morning as the band of moisture is carried in on the gusty
trade wind flow. The bulk of the rainfall will be focused on
windward slopes, but periods of showers are expected over leeward
areas from Kauai to Maui, as the breezy trades begin a slow
decline. The nearby upper level trough will continue to send
layered high clouds over the state, and a weak mid level ridge
noted on this afternoon`s soundings will likely be eroded as the
band moves through, opening the possibility for a few briefly
heavy showers tonight. A few of those showers may reach the high
summits of the Big Island as rain, though there is a small
possibility of some ice briefly developing late tonight.

Trade winds will decline into the light to moderate range late
Friday and Saturday as shower activity decreases. A shortwave
aloft will pick up the upper level trough that has been sitting
near the islands and push it overhead on Saturday. It does not
appear that it will produce a great deal of instability, but under
the weakened trade wind flow, it could trigger a few afternoon
showers over leeward terrain in the afternoon.

Light to moderate trade winds will hold Sunday through early next
week as upper level ridging moves overhead and produces a rather
stable pattern of mainly windward showers. Trades may become
disrupted during the middle of next week, but the spread in model
guidance remains significant, keeping uncertainty high.

&&

.AVIATION...
VFR conditions prevail through most areas across the state with
occasional MVFR due to CLD and SHRA over windward and mountainous
areas. Mid to high clouds will continue to move from the
southwest to northeast across the state. Breezy trade winds
continue through the evening, but will begin to gradually weaken
tonight.

AIRMET Tango in effect due to low level turb lee of mtn. This is
expected to continue at least through the evening.

AIRMET Sierra is in effect for tempo mountain obscuration over Kauai
N thru SE sections due to CLD and SHRA. This is expected to
continue into tonight and could be expanded at least to Oahu due
to showers upstream.

AIRMET Zulu is not in effect, however there could be TEMPO light
icing associated with the mid level CLD from Kauai to Maui in
layer 150-FL230.

&&

.MARINE...
High pressure northeast of Hawaii will weaken and track eastward
over the next couple of days as a front moves across the North
Pacific. As this occurs, easterly trades across the Hawaiian
coastal waters will gradually weaken. A Small Craft Advisory (SCA)
remains in effect for most Hawaiian waters, though it has been
dropped for waters surrounding Kauai and for leeward waters of
Oahu and Maui County as both wind speeds and seas gradually
decline. Further reductions in the area of the SCA are anticipated
by early Friday morning.

A new area of high pressure will become established north of the
islands this weekend, though trades will remain in the moderate
to fresh range this weekend through the first half of next week.

The current, medium period northwest swell peaked earlier today
and will continue to decline tonight into early Friday. Based on
observations and buoy data, surf along north and west facing
shores has fallen below advisory levels, and the High Surf
Advisory was allowed to expire. Another moderate, medium period,
northwest swell (310-330 degrees) is forecast to arrive Saturday
into Sunday, and could once again produce surf at or near
advisory levels along north and west facing shores. Looking ahead
to the middle of next week, a large, long period, northwest
(310-330 degree) swell has the potential bring advisory or even
warning level surf along north and west facing shores.

East shore surf will decline Friday into this weekend as trades
weaken over and upstream of the islands.

Small surf is expected along south facing shores for the next
several days.

&&

.FIRE WEATHER...
Critical fire weather conditions are not expected through the
week. A breezy and somewhat wet trade wind flow will keep humidity
elevated into Friday, with rainfall and trade winds decreasing
late Friday and Saturday. Light to moderate trade winds and rather
stable conditions will prevail Sunday through early next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Friday for Oahu Windward
Waters-Kaiwi Channel-Maui County Windward Waters-Big Island
Windward Waters.

Small Craft Advisory until 6 PM HST Friday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

&&

$$

DISCUSSION...Wroe
AVIATION...DT
MARINE...Vaughan
FIRE WEATHER...Wroe