595
FXHW60 PHFO 051300
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
300 AM HST Wed Jun 5 2024

.SYNOPSIS...
A surface ridge will settle southward during the next few days,
with moderate trades today becoming light Thursday and Friday
with land and sea breezes common across much of the state. The
ridge will lift northward this weekend allowing the trades to
gradually strengthen, with locally breezy conditions returning for
the first half of next week. Very dry conditions will greatly
limit shower activity through the weekend, with a slight increase
in windward showers expected early next week as the trades
strengthen to locally breezy levels.

&&

.DISCUSSION...
Currently at the surface, a 1024 mb high is centered around 1150
miles northeast of Honolulu, and is moderate trade winds across
the island chain. Infrared satellite imagery shows partly to
mostly cloudy skies across the state, with cloud coverage the
greatest over windward and mauka areas. Radar imagery shows very
little rainfall across the state, with nothing more than isolated
very light showers affecting windward slopes at coasts from time
to time. Main short term focus continues to revolve around trade
wind trends during the next several days.

High pressure northeast of the state will gradually weaken and
shift eastward during the next few days, with the associated ridge
shifting southward to a location just north of Kauai Thursday and
Friday. Moderate trades today, will become light Thursday and
Friday with land and sea breezes common across much of the state.
The ridge will begin to lift northward over the weekend allowing
the trades to gradually strengthen, with moderate to locally
breezy conditions returning for the first half of next week.

As for the remaining weather details, very stable and dry
conditions remain over the island chain, evident in the sharp
trade wind inversions, at or below 5 kft at both Hilo and Lihue
during the 12z soundings. Little change in the trade wind
inversion is expected through the weekend, which will greatly
limit shower activity across the entire state. The trade wind
inversion will begin to lift early next week, which should bring a
slight increase in trade wind showers, while still remaining
drier than normal for this time of year.

&&

.AVIATION...
Trade winds will gradually weaken over the next twenty-four to
thirty-six hours as the pressure gradient over the Islands
relaxes. Bands of clouds and light showers will favor east and
northeast facing slopes and coasts. Brief MVFR conditions are to
be expected in showers, otherwise VFR conditions will prevail
statewide.

Lingering mid-level atmospheric instability will encourage
convective showers over interior and upslope portions of the Big
Island today in the afternoon and early evening. Stability is
expected to increase later in the week as mid level ridging builds
over the state.

AIRMET Tango for low level turbulence lee of island terrain
remains in effect. This AIRMET will likely be cancelled toward
morning as low-level winds decrease.

AIRMET Sierra remains in effect for mountain obscuration for
windward sections of Maui, Molokai, and Oahu. Conditions are
expected to improve by late morning.

&&

.MARINE...
The ridge of high pressure is slowly sinking southward, and the
result is a downward trend to the moderate trade winds. The Small
Craft Advisory (SCA) has been cancelled for all Hawaiian waters
and looks to remain that way through the end of the week. Trade
winds are expected to continue to ease and diminish significantly
Thursday and Friday. Increasing moderate trades are expected
during the weekend as the ridge lifts northward.

The active south Pacific will continue to generate southerly
swells that will pass through the islands through the middle of
the month. The current south-southwest swell has started to
decline, and a continued gradual decline is expected through
Thursday. Another reinforcing south-southwest swell is expected to
arrive late Thursday and Friday, that is currently expected to
bring south facing shore surf around the seasonal average. A
larger swell is expected to move through the islands this coming
weekend, which will likely be near or at HSA levels of 10 feet. A
potentially even larger swell is looking increasingly likely late
next week that would bring surf well above advisory levels.

The current small northwest swell is on the decline as shorter
period energy is now moving through the islands. Another small pulse
from the northwest is expected to build through the day into
Thursday keeping surf elevated. Wind waves for east facing
shores will decline today and will diminish significantly after
today coinciding with the light winds through the weekend.

&&

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

&&

$$

DISCUSSION...Jelsema
AVIATION...Bedal
MARINE...Shigesato