Wahiawa, Hawaii Weather Forecast Discussion

125
FXHW60 PHFO 300154
AFDHFO
Area Forecast Discussion
National Weather Service Honolulu HI
354 PM HST Mon Sep 29 2025
.SYNOPSIS...
Dry weather until an band of moisture moves in with the trade
wind flow. Showers may increase Wednesday and Wednesday night,
followed by a shift to southeasterly winds.
&&
.DISCUSSION...
Trade wind speeds will trend lighter to moderate levels across
the islands tonight into Tuesday as the driving subtropical high
weakens. Clouds and showers will be limited through Tuesday and
focus windward, and over the Kona slopes of the Big Island during
the afternoon. A strong inversion around 7 kft and relative low
precipitable water values will limit any significant rainfall. A
band of clouds and showers, parhaps from an old, dissipated front,
will move in with the flow early Wednesday morning lingering into
Wednesday night. Showers will focus windward, and likely carry
over to leeward sides of the smaller islands at times Wednesday
night.
Trades will maintain moderate speeds through Thursday, then
weaken a bit more and veer southeasterly ahead of an intruding
low pressure system in the North Central Pacific. The southeast
flow will continue through Saturday, and localized land and sea
breezes may set up across much of the state. Expect, warm and
muggy conditions. This feature weakens Sunday with trade winds
coming back.
&&
.AVIATION...
Moderate to locally breezy trades will continue to favor limited
clouds and showers, mainly over windward and mauka areas.
Localized MVFR possible within passing showers, but most sites
will remain VFR.
AIRMET Sierra in effect for mountain obscuration due to low
clouds and showers over Kauai, Oahu, Molokai, Lanai, Maui, and
the Big Island. Conditions expected to improve later this morning.
&&
.MARINE...
Moderate to locally fresh easterly trade winds will persist
through much of the week. The Small Craft Advisory (SCA) for
windier waters and channels around Maui and the Big Island has
been cancelled with this afternoon`s forecast package as winds
trend slightly weaker.
A small medium period north swell filled in earlier today,
bringing small surf to north facing shores. This swell will
gradually fade heading into tomorrow and a series of small medium
period swells from the north and northwest will trickle in
through the rest of the week. A moderate medium period northwest
(330 degrees) swell is expected to arrive on Sunday, building
surf heights along north and west facing shores late this weekend
into early next week.
Surf along south facing shores will continue to slowly fade
tonight from a small medium period south swell. A series of small
medium period south swells will keep surf along south facing
shores from going flat through the week.
Surf along east facing shores will remain on the small side in
moderate trade wind flow, despite some small medium period swell
moving into the region over the next couple of days from former
tropical cyclone Narda.
&&
.FIRE WEATHER...
Winds expected to stay below fire weather threshold through the
week. Humidity levels will maintain and the current stable 7 kft
inversion will stay in place much of the week.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST this evening for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.
&&
$$
DISCUSSION/FIRE WEATHER...Foster
AVIATION...TS
MARINE...Farris

NWS HFO Office Area Forecast Discussion