834
FXHW60 PHFO 301923
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
923 AM HST Tue Apr 30 2024

.SYNOPSIS...
Moderate east to east-southeasterly winds will gradually
strengthen on Wednesday, while areas of thin high clouds move
across the region. Limited showers will be focused over windward
areas, while afternoon clouds and a few showers form over
sheltered leeward terrain each afternoon. Trade winds will
strengthen on Thursday and will become breezy and gusty Friday
through early next week. Rainfall will favor typical windward
slopes, with an increase in showers possible Saturday through
Monday as a disturbance aloft passes overhead.

&&

.DISCUSSION...
Hawaii remains under a stable east to east-southeast trade wind
flow, as a weak trough about 300 miles northwest of Kauai bisects
a pair of high pressure cells to the distant northeast and
northwest. Under this flow, expect modest rainfall over windward
slopes, and sheltered leeward areas will experience increased
clouds and a few showers this afternoon, mainly over the terrain.
Mid-level ridging will maintain stable conditions with an
inversion around 6,000 to 7,00 feet, and with no distinct areas of
moisture moving in on the trade wind flow, rainfall will remain
rather modest, generally under a quarter of an inch per day in the
wetter windward areas. In the upper levels, light westerly flow
aloft will lead to brief thinning of high clouds from west to
east today.

Trade winds will gradually strengthen and become more easterly
Wednesday and Thursday, as the trough to the northwest fills and
surface high pressure consolidates to the north. Winds will likely
be weak enough for some leeward sea breezes Wednesday afternoon,
but aside from typical showers on the South Kona slopes of the Big
Island, chances for leeward rainfall will be minimal. Continued
westerly flow aloft may bring some patches of thin high clouds.

A 1030 mb surface high will settle far north of the state late
Thursday and Friday, driving breezy and gusty trade winds and
mainly windward rainfall into early next week. A compact upper-
level low lingering west of the state Thursday and Friday will
eventually move overhead during the weekend and could enhance
shower activity sometime Saturday into Monday.

&&

.AVIATION...
Hawaii remains wedged between surface high pressure far northeast
of the state and a trough to the northwest. This pattern will
maintain light to moderate east to east-southeasterly flow today.
Expect scattered showers along the windward portions of the islands
and isolated showers elsewhere. Brief periods of MVFR ceilings
and visibility may occur with this activity, though not expecting
anything widespread. Sea breezes are forecast to develop along
portions of the leeward coasts by early afternoon, resulting in
some cloud buildups over leeward terrain and island interiors.
Land breezes should once again clear out those areas overnight.

No AIRMETs are currently in effect, nor expected through the
afternoon.

&&

.MARINE...
High pressure far northeast of the state will strengthen and
expand through the remainder of the week. A weak trough has
stalled to the northwest of the state and is expected to gradually
weaken over the next two to three days. In response, moderate to
fresh east-southeast trade winds today will strengthen to moderate
to locally strong by tomorrow afternoon. A Small Craft Advisory
(SCA) will likely initially be issued for the typical windy waters
around the Big Island and Maui sometime tonight and may be
expanded to include additional waters Friday or Saturday.

Tiny surf will persist along north facing shores through Friday,
with a small pulse of northwest swell swell expected this
weekend. A small long period south-southwest swell will peak today,
then ease on Wednesday. Otherwise, small background level surf on
south shores for the rest of the week. Choppy surf along east
facing shores will decline over the next twenty-four hours, then
gradually increase as trade winds rebuild. Rough east shore surf
will likely rise above seasonal average Friday into the weekend.

&&

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

&&

$$

DISCUSSION...Wroe
AVIATION...TS
MARINE...Bedal/Vaughan