Kaneohe Base, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

618
FXHW60 PHFO 181348
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
348 AM HST Thu Dec 18 2025

.SYNOPSIS...

A band of thick clouds with moderate to locally heavy showers and
a few thunderstorms will linger near Kauai and Oahu today
associated with a dissipating front. The band of clouds will
become more diffused and lift northwestward back over Kauai
County tonight, providing continued chances showers with drying
trend for Molokai thru Oahu. Ridging aloft will slowly build back
in over the islands marking a return of more stable easterly trade
wind weather this weekend. However, cloudy conditions will
persist for the next couple of days. Moderate to strong trades
with more typical stable conditions will build back Sunday into
early next week.


&&

.DISCUSSION...

An active weather pattern continues across the western portion of
the state this morning as a weakening front remains stalled west of
Kauai. A band of clouds with heavy showers with isolated
thunderstorms training from the southwest to northeast has remained
nearly stationary over northern Oahu. Rainfall totals overnight range
from 1 to 3 inches. Convective activity shows a slight downward trend
this morning within the main narrow rainband lingering over northern
Oahu. Drier conditions have be observed over the rest of the
state.

Hi- res models continue to suggest the band of showers to train over
Oahu through much of the day while gradually becoming more diffused
with a few stray showers reaching Molokai. This band will shift
northwestward later this morning and afternoon, keeping chances of
heavy rain possible for Oahu and Kauai. Southeast winds build in
over Maui County and the Big Island.

The Flood Watch will continue through this afternoon for Kauai
County and Oahu. The watch may need to be extended for Kauai through
Friday morning as another upper level shortwave trough swings down
increasing instability over Kauai. Depending on surface level
convergence and where the lingering band of showers ends up this
afternoon and evening, this pattern could reinvigorate an active
shower pattern through the evening hours. Chances for light to
moderate showers will increase along along southeast exposures of
the Big Island and Maui County tonight into Friday morning as
disturbance move in from the south.

Friday, a low level ridge will build in over the islands from the
south drawing low level moisture up to the mid levels, generating
a mix of high, mid, and low level layered clouds. Best chances of
showers will linger over the western half of the state where the
greatest upper level instability will linger.

Saturday, light to gentle easterly trade winds will return as a
high builds northeast of the state. Low to upper level ridging
will still allow moisture being drawn up over the state from the
southwest to northeast keeping mostly cloudy conditions. Expect
showers to mainly focus along windward and mauka areas.

Sunday into early next week trades are expected to strengthen to
moderate to strong levels with more stable conditions developing
into early next week. Bands of showers trapped within the trade
wind flow will remain focused mainly along windward and mauka
areas.


&&

.AVIATION...
A convective cloud band with embedded thunderstorms continues to
move into Oahu this morning. Expect periods of MVFR and isolated
IFR conditions in showers and thunderstorms along the cloud band.
These enhanced showers will continue today over Oahu, then slowly
drift these low cloud CIGs and showers northward into Kauai later
tonight. A weak disturbance moving up from the south will bring
periods of MVFR conditions with additional low clouds and
enhanced showers into the islands of Maui and the Big Island on
Friday.

AIRMET Sierra remains in effect for tempo mountain obscurations
across Oahu and Molokai this morning. Mountain obscurations will
likely return to Kauai later this afternoon. IFR conditions over
Lanai will continue through the morning hours.

AIRMET Tango is in effect for tempo moderate turbulence below 080
over and north through east of island terrain on Oahu and Molokai.
This low level turbulence should decrease this morning.


&&

.MARINE...
A trough near Kauai and Oahu has brought isolated to scattered
thunderstorms and numerous showers along the boundary overnight
and looks to continue through Friday over the western coastal
waters. Gentle to locally moderate southerly winds are expected
over the coastal waters today except areas along the boundary that
could reach Small Craft Advisory criteria winds associated with
the thunderstorms. The general southerly wind flow will gradually
decrease to light to gentle through Friday night. Easterly trade
winds look to slowly build from the east to west this weekend with
the potential for Small Craft Advisory over the windier waters
and channels around Maui County and the Big Island by Sunday into
early next week.

Surf along north facing shores will remain elevated with a mix
across the spectrum from the west northwest to the north. The new
north northwest swell will look to build throughout the day well
into High Surf Advisory (HSA) criteria and peak this afternoon
into the evening. The HSA may need to be extended through Friday.
The slightly smaller west northwest swell will look to fill in
this morning and quickly fade out Friday. A combination of the north
northwest and north swells will keep surf heights elevated
through the weekend but guidance shows it at or just below HSA
levels.

East facing shores will remain small given the lack of trade winds
upstream of the islands but areas exposed to the north swell will
see an uptick through the rest of the week. As trade winds fill
in later this weekend, east shores could become rough and choppy
by early next week. Surf along south facing shores will remain
small today due to short period wind wave chop, mainly over the
western islands along the boundary but elsewhere should remain
flat to tiny through the weekend.


&&

.FIRE WEATHER...

Wet weather conditions and isolated thunderstorms will trend down
slightly today across the western islands. Periods of clouds and
scattered showers are expected for Molokai and Lanai, with drier
conditions remaining in place over Maui and the Big Island. Trade
winds and increasingly stable conditions will slowly return to the
western half of the state from Friday into the weekend. Wind
speeds and humidity levels will keep weather conditions below
critical fire thresholds throughout next week.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Flood Watch through this afternoon for Niihau-Kauai Leeward-
Kauai Mountains-Waianae Coast-Oahu North Shore-Olomana-Central
Oahu-Waianae Mountains-Kauai North-Kauai East-Kauai South-East
Honolulu-Honolulu Metro-Ewa Plain-Koolau Windward-Koolau
Leeward.

High Surf Advisory until 6 AM HST Friday for Niihau-Kauai
Leeward-Waianae Coast-Oahu North Shore-Kauai North.

High Surf Advisory until 6 AM HST Friday for Maui Windward West-
Molokai Windward-Molokai North-Molokai West-Maui Central Valley
North-Windward Haleakala.

Small Craft Advisory until 6 AM HST Friday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters.


&&

$$


DISCUSSION...Almanza
AVIATION...Bohlin
MARINE...Shigesato
FIRE WEATHER...Almanza