Current Conditions
Temp10.2 C
RH7 %
WindNE 12 mph
RoadOpen (4x4)
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Hawaiian Islands Synoptic Discussion and Guidance

013
FXHW60 PHFO 261936
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
936 AM HST Tue May 26 2020

.SYNOPSIS...
Light winds today will strengthen tonight and Wednesday, with
moderate to occasionally breezy trade winds continuing through next
weekend. The trade winds will focus low clouds and showers over
windward areas, but today's light winds will also allow a few
showers to develop over leeward areas in the afternoon. Varying
amounts of benign high clouds are expected to move over the islands
through Friday.

&&

.DISCUSSION...
Little change to the forecast this morning. Did increase the sky
cover through tonight to take into account the high clouds moving
overhead from the south. Not expecting any significant change to
the forecast today.

A ridge to the north of the islands is expected to lift the
north, allowing trade winds to filter back into the region from
south to north tonight and Wednesday. A new high building in north
of the islands will help to increase our trades to moderate levels
through the weekend.

Meanwhile, an upper level low to the southwest of the islands is
ushering in some high clouds from the south, and those clouds are
impacting the eastern half of the state this morning. The upper
level low is expected to gradually move to the west, which will
spread the high clouds to the other islands over the next day or
so. The high clouds will linger through Friday, before thinning
and exiting the area to the west.

With the returning trade winds, expect showers to be focused over
the windward sides of the islands. Today we could still see some
development over leeward and interior areas this afternoon with
the light winds. There are indications in the long range models
that we could see an increase in trade wind shower activity early
next week.

&&

.AVIATION...
Expect late morning/afternoon sea breezes to develop with light
winds still in place with possibly a few inland showers. That
should change beginning later today and tonight as the high builds
and strengthens to the northeast, increasing the wind speeds.
That trend should continue for the next few days. This means that
any showers that develop will favor windward mauka areas with
passing MVFR conditions in those areas as well, especially
overnight and into the early morning hours. VFR conditions are to
be expected elsewhere.


Low clouds and a few lights showers still have lower clouds across
north through southeast sections of Oahu so will maintain AIRMET
Sierra for mountain obscuration in those areas.

&&

.MARINE...
Light to moderate east-southeast winds will hold today over the
western end of the state, which will allow land and sea breezes to
develop near the coasts. Farther east over Maui County and the
Big Island, moderate to fresh trade winds will return. By
Wednesday afternoon, fresh to locally strong trade winds are
expected across the state as a ridge high of high pressure
strengthens north of the state. Winds may reach Small Craft
Advisory levels across the typically windy waters around the Big
Island and Maui Wednesday into the weekend.

Surf along north facing shores will gradually trend down today as
the small, medium-period, north-northwest swell fades. An upward
trend is expected Wednesday through the second half of the week
due to a storm-force low that has developed around 1000 nautical
miles north-northwest of the state. This swell will shift around
out of the north late Thursday through Saturday as the source
passes to the north today.

Surf along south facing shores will remain small into midweek
with mainly a combo of south-southwest and south-southeast energy
moving through. An upward trend is possible by Thursday night as a
new, long- period, south-southwest swell arrives. This will hold
through Friday, then gradually trend down over the weekend.

For the extended, a strong low pressure system currently
developing southeast of New Zealand could produce a moderate south
swell by early next week. Latest WW3 guidance is suggesting surf
picking up Monday and peaking around the middle of next week along
south facing shores.

Surf along east facing shores will remain below the May average
through the weekend due to the lack of strong trades upstream of
the state.


&&

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

&&

$$


DISCUSSION...M Ballard
AVIATION...Chevalier
MARINE...Kino

Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office