420
FXHW60 PHFO 090149
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
349 PM HST Tue Oct 8 2024

.SYNOPSIS...
Moderate northeast trades persist as a surface trough approaches
the islands from the east. The trough will move in and fade, but
bring an increase in clouds and showers Wednesday night through
Friday. Winds will also taper in response to a stalled front to
the north and then strengthen early next week.

&&

.DISCUSSION...
A weak broad upper trough will persist over Hawaii through
Thursday. Moderate northeast trades persist as a surface trough
approaches the islands from the east. The trades from a distant
high will carry scattered windward showers across all islands
through Wednesday. The trough will slowly track east to west
across the islands as it fades Wednesday night into Friday. Low
clouds and showers along the surface trough will move in an bring
an increase to rain chances during this period, particularly
along windward sides of the islands. Meanwhile, winds will taper
off Thursday through the weekend as a weak front stalls well
north of the state. Winds may be sufficiently weak for localized
land and sea breezes in some areas that are more sheltered from
the trade wind flow. This would allow for some leeward interior
cloud build up during the afternoon hours and clearing overnight.
Trades will then strengthen back to moderate levels by early next
week as the aforementioned front dissipates and the surface
pressure gradient restrengthens over the area.

&&

.AVIATION...
Expect moderate to locally breezy trades through the rest of the
work week. Showers and low ceilings will bring brief periods of
MVFR conditions to windward and mauka areas. VFR conditions should
prevail elsewhere.

No AIRMETs are currently in effect and none are expected through
today.

&&

.MARINE...
A series of cold fronts moving out of the Gulf of Alaska will
disrupt the re-establishment of high pressure located north and
northeast of the Hawaii waters. This will result in a weak
pressure gradient back toward and over the islands. A more
slackened gradient will produce lower end moderate with locally
fresh trades across the island channels through Thursday
afternoon. Trades will drop off to more gentle speeds Friday into
the weekend.

A small, medium to long period a 4 to 5 foot northwest north
swell (330-340 degree) will be on a very slow decline through
Wednesday. This swell still has enough energy to produce over
head high surf along the best targeted reefs, chest to head high
in most other spots, into tomorrow afternoon. The next significant
north swell will likely arrive Sunday and Monday. This near due
north swell originating from a long solid gale fetch down the
north great circle line from the Aleutians is forecast to come in
large enough to push surf to High Surf Advisory heights early next
week. A moderate size, medium to long period south southwest
swell (180-190 degree) is still coming in above forecast guidance.
Local nearshore south buoys are observing a solid 3 to near 4
foot, 13 second period, south swell that is equating to many fun
size waist to slightly above chest high sets along many southern
exposures. The next long period south swell arrival Thursday will
reinforce this ongoing steady swell. Surf along west-facing shores
will be influenced by a mixture of both north and south swells.
Thus, expect western exposures to remain elevated as these ongoing
north and south swells will hold or be slow to fall. East-facing
shore chop will not be overly rough and will steadily decline, or
conditions will improve, as wind waves subside through late week
in response to lighter trade flow.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$


DISCUSSION...Foster
AVIATION...Powell
MARINE...Blood