Royal Kunia, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

851
FXHW60 PHFO 111326
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
326 AM HST Fri Apr 11 2025

.SYNOPSIS...
Moderate to locally strong trade winds will persist through early
next week with clouds and showers generally favoring windward and
mountain areas. Remnant bands of unsettled clouds and showers
from an old frontal boundary will continue to drift onto the
western islands through tonight. Thereafter, expect a wetter than
normal trade wind pattern through Tuesday, followed by a
transition to lighter winds through next Friday.

&&

.DISCUSSION...
Remnant bands of unsettled isolated to scattered showers continue
to stream across the western islands, with periods of heavier
showers, namely across Kauai and Oahu. Expect showers and cloud
cover to persist across windward and mountain areas, occasionally
lingering into the leeward areas. The 12z soundings indicate the
inversion is a bit higher over Kauai than over Hilo (10000 feet
versus 8000 feet, respectively), supporting the cloud band as seen
on satellite and radar.

A 1036mb high pressure ridge remains quasi-stationary well north
of the islands and will begin to slowly propagate eastward over
the next few days, maintaining the moderate to locally strong
trades and wetter than normal conditions across the region
through early next week. Additionally, latest model guidance
suggests an ingress of a mid-level low just west of the islands
early next week, which may briefly increase instability.

By Wednesday of next week, the aforementioned high pressure ridge
will begin to exit to the northeast, with the introduction of a
cold frontal system moving into the Central Pacific basin in its
wake. Latest model guidance is not in good agreement with the
progression of the aforementioned cold frontal system, however, as
confidence remains low with some guidance suggesting winds may
veer in a more east-southeasterly direction, leading to land and
sea breezes expanding in coverage. Conversely, other guidance
projects lighter trade winds to remain the dominant feature
through the outlook period.

&&

.AVIATION...
Moderate to breezy trade winds will continue for the next few
days. Low cigs and SHRA should mainly impact windward and mauka
locations. MVFR conds possible in heavier SHRA but VFR should
prevail.

AIRMET Sierra is in effect for mtn obsc for windward locations of
Kauai, Oahu, Molokai, and Maui.

&&

.MARINE...
Surface high pressure approximately 950 nautical miles northeast
of Oahu will continue to advance east and settle northeast of the
islands this weekend. This will drive fresh to locally strong
trade winds the next few days. A Small Craft Advisory (SCA)
remains in effect for the majority of the waters through this
afternoon, with the exception of the leeward Maui and windward Big
Island waters. A slightly weakened pressure gradient through the
weekend will allow water-wide east trades to drop off a touch. SCA
winds will hang on for the typically windier waters surrounding
Maui County and Big Island into early next week.

A small, short to medium period northwest swell will produce chest
to slightly above head high surf along north-facing shores this
morning. North surf will fall back to average waist to chest high
heights by Saturday. A slightly larger northwest swell is expected
to build in on Monday and decline Tuesday and Wednesday.

Average waist to near head high south-facing shore surf will hold
through the morning before beginning an afternoon decline. Typical
small, long period background level surf will return this weekend.

A long, fresh trade fetch over and upstream of the islands will
produce rough surf along eastern-facing exposures through the day.
The largest waves have been observed near Kauai, where buoys have
been reporting overnight near 10 foot significant wave heights.
Oahu and Kauai east-facing shore surf will peak just below High
Surf Advisory thresholds this morning. Along with stronger
trades, elevated seas surrounding Kauai and Oahu will also warrant
today`s SCA. Agitated east shore wind wave chop will begin to
abate early next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST this evening for Kauai
Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-
Kauai Channel-Oahu Windward Waters-Oahu Leeward Waters-Kaiwi
Channel-Maui County Windward Waters.

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

&&

$$


DISCUSSION...Pierce/Birchard
AVIATION...Walsh
MARINE...Blood