534
FXHW60 PHFO 150618
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
818 PM HST Wed Aug 14 2024

.SYNOPSIS...
Moderate trade winds will continue through Thursday, then return
to breezy levels Friday through early next week. Showers will
favor windward and mauka locations, particularly during the
overnight and early morning periods as areas of moisture move
through.

&&

.DISCUSSION...
A broad surface trough (remnants of former TC Emilia), located
around 200 miles north-northeast of Hilo, will continue westward
tonight through Thursday night, weakening the local trades to
moderate levels. This broad surface trough, combined with a mid-
level trough and an increase in low-level moisture, will lead to
better shower coverage, primarily for windward and mauka
locations. The evening radar reflects this and depicts an increase
in shower coverage filling in over the windward waters of the
small islands, which should continue into Thursday. A few
interior/leeward showers are possible Thursday afternoon, where
localized sea breezes form.

Breezy trade wind conditions are expected to return Friday
through the weekend as the aforementioned trough begins to track
away from the state and the deep-layer ridge strengthens. A modest
increase in low-level moisture, accompanying another low- to mid-
level trough passing to the south, could translate to increasing
shower coverage Sunday through Monday, most likely over the eastern
end of the state.

&&

.AVIATION...
Moderate to locally breezy trades will deliver low clouds and brief
showers to windward areas through the forecast period. An
approaching trough will weaken winds slightly, veer towards a more
easterly direction, and allow an increase in low- level moisture
over the western end of the state tonight into Thursday. VFR
conditions will prevail with isolated MVFR CIG over windward
areas.

No AIRMETs are currently in effect. AIRMET Sierra for mountain
obscuration may be needed over Kauai and/or Oahu tonight.

&&

.MARINE...
Moderate to locally strong trade winds will prevail through early
next week. A weak surface trough passing by north of the islands
will keep the trade winds below Small Craft Advisory thresholds
tonight and Thursday. The trades will strengthen back to SCA
levels over the typically windy waters around Maui and the Big
Island Thursday night or Friday, then hold at these levels through
early next week.

Several small long-period swells from the south and southeast
will produce small surf along south facing shores through the
work week. A more significant south swell will arrive late Sunday
and Sunday night, peak above the summertime average Monday, then
slowly lower through the middle of next week.

Seasonally flat to tiny surf is expected through early next week
for north facing shores. East shore surf will remain below normal
during the next couple days, then trend higher over the weekend
and rise to near seasonal levels early next week.

The combination of the full moon and water levels running around
0.5 ft higher than normal should produce minor coastal flooding
each afternoon along the shorelines across the state beginning
8/18 and likely continuing through 8/20. A Coastal Flood Statement
will eventually be needed as we get closer to the event.

&&

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

&&

$$

DISCUSSION...Gibbs
AVIATION...Shigesato
MARINE...Jelsema