000
FXHW60 PHFO 200307 AAA
AFDHFO

Area Forecast Discussion...UPDATED
National Weather Service Honolulu HI
507 PM HST Fri Apr 19 2024

.SYNOPSIS...
Breezy trades will briefly weaken over the weekend, before
increasing again early next week. Mostly dry conditions will
prevail, with clouds and brief showers favoring windward and
mauka locations, mainly during the overnight through early
morning hours, as areas of moisture move through periodically.

&&

.DISCUSSION...
Updated to upgrade the Wind Advisory to a High Wind Warning for
the Big Island Summits this evening.

Winds at the Big Island Summits have continued to come up
significantly late this afternoon, higher than most guidance, so
have upgraded the Wind Advisory to a High Wind Warning, in effect
through Saturday afternoon. Winds look to remain very strong there
through Saturday as an upper-level shortwave swings through, then
trend down through the rest of the weekend.

Otherwise and elsewhere, surface high pressure far north-northwest
of the state will drift to the east, with an associated ridge
remaining north of the region. Breezy trades will ease into the
light to moderate range over the weekend as the ridge to the north
weakens due to a low passing far to the north. The southern extent
the aforementioned upper trough associated with this low could
support a slight increase in windward shower coverage during the
overnight/early mornings tonight into Sunday.

Rising upper heights along with a strengthening surface high to
the north will support relatively dry conditions with breezy
easterly trades through the majority of next week. Expect clouds
and limited showers to ride in on the trade wind flow from time to
time, remaining focused over the typical windward sides of the
islands and concentrated during the overnight and morning hours.
Clouds and limited showers are also expected over the west slopes
of the Big Island each day, mainly during the afternoon and
evening hours.

&&

.AVIATION...
Moderate trade winds will remain in place for the rest of today.
They will gradually weaken through the weekend. Low clouds and
SHRA will bring brief MVFR conds to the windward and mauka
locations of the islands.

AIRMET Sierra for mtn obsc remains in effect for Kauai, Oahu,
Molokai, Maui and the Big Island. This may need cancelled later
this evening if conds improve.

&&

.MARINE...
A low pressure system passing far to the north of the state will
weaken the subtropical ridge of high pressure. This will result
in a slight weakening of the trade winds across the coastal and
offshore waters. A Small Craft Advisory in effect for the usually
windier zones around Maui County and the Big Island is on track to
be dropped by 6 PM HST today. The ridge of high pressure should
rebuild early next week, which should produce fresh to locally
strong trades once again.

Near shore buoys today showed an overall gradual decline of the
current south-southwest swell. This trend should continue into
Saturday. On Sunday, the first of a series of small south to
south-southwest swells is forecast to arrive. These swells should
prevent south-shore surf from going flat over the next week. For
the north-facing shores, a small, short-period north swell should
continue into Saturday. A moderate, medium-period north swell is
expected to arrive on Saturday night. Surf along east-facing
shores will remain small through the weekend and may increase
slightly early next week as the trades strengthen.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 6 PM HST Saturday for Big Island Summits.

&&

$$

DISCUSSION...TS
AVIATION...Walsh
MARINE...Kodama