Weather Service Report


196 
FXHW60 PHFO 262000
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
1000 AM HST SUN JUN 26 2016

.SYNOPSIS...
High pressure centered far north of the state will maintain 
moderate to breezy trades over the islands through the next few
days. Clouds and passing showers will favor windward and mauka
areas of the smaller islands, with mainly dry conditions leeward.
The Kona slopes on the Big Island will continue to see clouds and
widely scattered showers each afternoon and evening, followed by
clearing skies each night and morning. A wetter and more unstable
trade wind pattern is expected Tuesday through Friday.

&&

.DISCUSSION...
Breezy trade winds continue today with only a few windward
showers expected. Trade winds will continue through the week with
high pressure firmly entrenched to our north. Dry upstream
conditions suggests a dry trade wind pattern will continue over
the islands for the next few days before giving way to wetter by
Wednesday.

Global models agree with a sharp change in the upper level
pattern this week. Current conditions show the islands under an
upper level ridge with subsiding air creating a cloud capping
temperature inversion near 8 thousand feet. However, an upper
trough rounding the ridge from the north looks to bring cold air
aloft over the state late Tuesday, and remaining overhead into
Friday. The cold air aloft will remove the cloud capping
inversion, allowing for increased vertical cloud growth and the
chance of heavier and more plentiful showers. High pressure at the
surface will remain throughout, so trade winds will continue to
push moisture into the windward slopes where the majority of
showers will focus. The instability from the upper trough will
allow for some of the windward showers to reach leeward locations,
with some brief downpours possible.

If the forecast holds, there will be potential for enhanced
showers and even isolated thunderstorms from Wednesday into
Friday. The evolution of the upper trough will be monitored, and
modifications to the midweek forecast will continue as confidence
increases.

&&

.AVIATION...
High pressure north of the state will keep a trade wind flow in
place, with clouds and showers focused primarily across windward
and mauka areas. Brief MVFR cigs/vsbys will be possible in passing
SHRA in windward locales, but predominantly VFR conditions are
expected through the TAF forecast period.

No Airmets are currently in effect, and none are anticipated
through the remainder of the day.

&&

.MARINE...
A strong high far North Northwest of the area is producing locally
strong trade winds. The high will move South and weaken over the
next few days and the winds may drop below Small-Craft-Advisory
(SCA) strength by Tuesday. A strong new high will build Northeast of
the area through the second half of the week. The trade winds will
strengthen and could reach near-gale strength by next weekend.

A swell from the Southern Hemisphere is expected to arrive today,
peak Monday and Tuesday below the advisory threshold, then
subside. As the trade winds strengthen later this week, surf along
east facing shores could reach advisory levels.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Monday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big 
Island Southeast Waters.


&&

$$

Morrison...Public
Jelsema...Aviation
Donaldson...Marine

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Western Regional Climate Center, wrcc@dri.edu