Wildfire in Hawaii, August 30 to 31, 2020

Area Forecast Discussion
National Weather Service Honolulu HI
1001 AM HST Sun Aug 30 2020

.SYNOPSIS...
A rather dry trade wind weather pattern is expected over the next
several days as high pressures resides to our north. Clouds and
passing light showers will favor windward and mauka areas with
most leeward locations remaining dry.

&&

.DISCUSSION...
A 1032 mb surface high is centered far to the north northeast of
the area with a ridge extending west southwest from the highs
center to a position far to the northwest of Kauai. This places
the islands in a breezy trade wind environment. The airmass is
rather stable and dry with a mid level ridge lying just to our
north and precipitable water values ranging from 1.1 to 1.4
inches. Radar imagery shows just a few light showers embedded in
the trades primarily falling over windward and mauka areas. Expect
little change through the evening hours with the exception of the
leeward Big Island slopes seeing clouds and few showers forming
during the afternoon hours due to daytime heating. Little change
in this weather pattern is expected through Tuesday.

Beginning Wednesday, the high is forecast to drift westward and
weaken as a weak area of low develops far to our northeast. The
will cause the pressure gradient to slacken resulting in lighter
trade winds. The airmass is expected to remain dry and stable
through Friday so only light passing showers are expected over
windward and mauka areas. Clouds and a few showers are also
expected over the leeward Big Island slopes during the afternoon
and evening hours.

As we head into next weekend, the low to the northeast is forecast
to weaken while the high to our north strengthens. This should
allow for a slight uptick in trade wind speeds. Light passing
showers will continue to favor windward and mauka areas and will
be highly dependent on incoming moisture availability.

&&

.AVIATION...
Locally strong trades and a stable island atmosphere will remain
in place through Monday, delivering limited low-level moisture.
Relatively shallow low clouds will bring isolated MVFR conditions
to windward slopes and coasts, most active during the night and
morning. Conditions at the terminals will be prevailing VFR, and
AIRMET Tango for moderate low-level turbulence near and downwind
of the terrain remains posted. No other AIRMETS are in effect or
are expected.

&&

.MARINE...
High pressure northeast of the state will maintain fresh to
locally strong trade winds through at least Monday, then gradually
decrease as we approach the middle of the week. Winds will become
moderate Wednesday and Thursday and then gradually strengthen
into next weekend. A Small Craft Advisory for winds is posted for
the typical windy coastal zones plus Kaiwi Channel through
Tuesday. Breezy winds will also boost surf along east facing
shores over the next several days before dropping by midweek. A
small, short period northwest swell will be possible Wednesday
into Thursday.

Small, moderate period swells out of the south, southeast and
southwest will continue to produce tiny to small surf along south
facing shores throughout most of this week. A slightly larger
long-period south swell is expected to fill in towards the end of
the week and may bring surf heights around the summer average (3
to 5 feet) next weekend.

&&

.FIRE WEATHER...
Due to the lack of any significant rainfall through the summer
months, fuels have become very dry across portions of the state.
These dry conditions combined with breezy trades and relative
humidities dipping below 40 percent through the afternoon hours
will support extreme fire behavior through Monday.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 6 PM HST Monday for Niihau-Kauai Leeward-
Oahu South Shore-Waianae Coast-Oahu North Shore-Central Oahu-
Waianae Mountains-Molokai Leeward-Lanai-Maui Leeward West-Maui
Central Valley-Leeward Haleakala-Kona-South Big Island-Kohala.

Small Craft Advisory until 6 PM HST Tuesday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

Small Craft Advisory until 6 AM HST Tuesday for Kaiwi Channel.

&&

DISCUSSION...Burke
AVIATION...Powell
MARINE...Kino
FIRE WEATHER...BURKE