AFOS product AFDHFO
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Product Timestamp: 2025-11-30 14:07 UTC

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FXHW60 PHFO 301407
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
407 AM HST Sun Nov 30 2025

.SYNOPSIS...
An approaching weak cold front will stall out just Northwest of
Kauai and continue to keep the high pressure ridge entrenched 
directly over the Hawaiian Islands. Large scale stability under
this ridge and drier southeasterly wind flow will minimize shower
activity into Tuesday. Another cold front will approach the 
islands from the northwest on Tuesday. Clouds and showers along 
the frontal band may stall over Kauai by Wednesday, increasing 
shower activity over the Garden Isle. Trade winds will build back 
into the region and strengthen from Thursday onward, bringing back
periods of passing showers to windward and mountain areas, 
favoring the typical overnight to early morning hours.

&&

.DISCUSSION...
This mornings satellite picture shows a weak cold frontal system
approaching the islands from the northwest and a weak high
pressure ridge over the Hawaiian Islands. Bands of high level
cirrus ice crystal clouds associated with this approaching system 
are passing over the island chain. The low level stratocumulus
clouds near the islands appear very stable with little rainfall
expected under the stable subsidence of the ridge anchored 
directly over the state. The subsidence temperature inversion
heights, as measured by weather balloon observations from Lihue
and Hilo at 2 AM HST (12Z) this morning, are hovering between the
5,000 and 6,500 feet elevation level. This temperature inversion
will continue to serve as a stable capping force for cloud
development, reducing shower potential. 

Additional stable dry trends are also due to southeasterly wind 
flow that places the smaller islands in a drier rain shadow of the
Big Island with clouds tracking more parallel to island mountain 
ranges, limiting orographic lifting of clouds over windward 
mountains. Lighter large scale winds will also keep daytime 
onshore sea breezes going for most areas through Tuesday. VOG 
(Volcanic smOG) from the Kilauea Volcano will also ride into all 
islands on these drier southeasterly winds. This VOG will appear 
as haze affecting all islands today, with some decreasing trends 
from Monday onward as the low level steering winds begin to 
change.

This dry southeasterly wind pattern will continue for most areas
through Tuesday or Wednesday. On Wednesday, medium range model
solutions are showing changes in our local weather pattern as a 
weakening cold front moves into Kauai and stalls. Shower activity 
will likely increase over Niihau and Kauai for 24 hours, until 
this front breaks apart and drifts westward away from the islands.
Differences between the main operational American (GFS) and 
European (ECMWF) remain, with the ECMWF model showing wetter 
trends for the islands in Kauai County.

A high pressure system will build in north of the state for the
second half of the week, increasing easterly trade winds across 
the region. Expect some southeasterly winds to linger on Thursday,
with winds becoming more easterly and stronger from Friday 
through next weekend. As the ridge over the islands lifts 
northward, our typical trade wind shower activity returns with 
brief passing showers forecast along windward and mountain areas, 
favoring the typical overnight to early morning hours.

&&

.AVIATION...
Light southeasterly large scale winds will produce a stable land
and sea breeze weather pattern across the state. Upslope sea 
breezes each day will turn into lighter downslope land breezes 
each night. Stable conditions aloft will keep VFR conditions
firmly in place across the state through at least Monday.

There are currently no AIRMETs in effect, and none are 
expected.

&&

.MARINE...
A high pressure ridge will remain over or just north of the state
through Tuesday and maintain light to moderate southeast 
background flow. This pattern will allow for nocturnally driven 
sea breeze/land breezes along waters adjacent to the islands 
coasts. By Wednesday, a front will approach Kauai from the 
northwest, but models show it weakening into a trough then 
retreating to the west. Typical easterly trades are finally 
progged to return late this week into next weekend as surface high
pressure builds to the northeast of the area.

A series of large to extra large west-northwest to northwest 
swells will pass through the waters over the next several days. 
The current long period west-northwest swell (300-320 degree) 
continues to peak this morning at an impressive 15-17 feet, as 
noted on the latest Waimea Bay Buoy observations. A Small Craft
Advisory will remain in effect through noon on Monday for marine
zones with exposed waters for combined seas over 10 feet. This 
swell is expected to slowly lose energy this afternoon through 
tonight, but continue to produce surf above warning criteria. 
Thus, the High Surf Warning will remain in effect through noon on 
Monday for exposed north and west facing shores of most islands. 
Surf should drop down to advisory levels by Monday afternoon as 
the swell energy eases. Another large, long period northwest swell
(310-330 degree) is forecast to fill in on Wednesday, peak 
Thursday, then slowly subside on Friday. Surf may once again 
approach warning levels.

East shore surf will remain small through the weekend due to weak
winds. Select south facing shores could experience westerly wrap 
from this weekend's large west northwest swell passage.

&&

.FIRE WEATHER...
Rather dry conditions are expected to persist through Tuesday. 
Winds will be light and variable under a stable land and sea 
breeze pattern, preventing critical fire weather thresholds from 
being approached. With the inversion holding around 6,500 ft, very
dry conditions will persist on the upper elevations of the Big 
Island and Maui.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Warning until noon HST Monday for Niihau-Kauai Leeward-
Waianae Coast-Oahu North Shore-Maui Windward West-Kona-Kohala-
Kauai North-Molokai Windward-Molokai North-Molokai West-Maui 
Central Valley North-Windward Haleakala.

Small Craft Advisory until noon HST Monday for Kauai Northwest 
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Kaiwi Channel-Maui County Windward Waters-
Big Island Windward Waters.

&&

$$

DISCUSSION...Bohlin
AVIATION...Bohlin
MARINE...JT
FIRE WEATHER...Bohlin