Drought in Hawaii, June 8 to 30, 2021

Area Forecast Discussion
National Weather Service Honolulu HI
841 PM HST Mon Jun 7 2021

.SYNOPSIS...
A high pressure ridge north of the islands will keep moderate to
breezy trade winds with brief passing windward and mountain
showers in the forecast into Friday. The ridge will weaken from
late Friday into the weekend as a weakening cold front approaches
from the north. Lighter wind speed trends are expected along with
a slight decrease in shower activity this weekend.

&&

.DISCUSSION...
The large scale weather picture remains unchanged tonight as a
large high pressure ridge remains in place north of the region
with a nearly stationary low pressure system west-northwest of the
islands near the Dateline. Satellite imagery shows stable clouds
drifting into each island on the trade winds. Local radar shows
brief passing showers drifting through the islands mainly
affecting windward and mountain sections. Drier conditions are
observed over leeward areas.

The large subtropical ridge north of the state will continue to produce
moderate to breezy trade winds into Friday. A combination of
breezy surface winds and passing mid level disturbances will keep
brief passing showers in the forecast favoring windward and
mountain areas. daily rainfall amounts will remain light for most
locations.

Weather conditions change a bit from Friday into the weekend as a
dissipating cold front approaches the islands from the north.
This frontal trough will break down the high pressure ridge north
of the islands and decrease the trade winds into the light to
moderate range. Shower activity will also trend a bit lower this
weekend as wind speeds decrease.

The high pressure ridge builds back in north of the region late
Sunday into Monday with moderate trade winds in the forecast. A
cloud boundary associated with a dissipated cold front will
linger just north of the main Hawaiian Islands. The latest long
range guidance continues to suggest any clouds and showers with
this feature will remain just north of Kauai with little impact in
our local island weather.

&&

.AVIATION...
High pressure north of the state will keep moderate to breezy
trade winds in place through Tuesday. Scattered showers will
favor windward slopes and coasts. Brief MVFR cigs/vsbys will be
possible, but predominantly VFR conditions are expected.

AIRMET TANGO remains in effect for moderate low level turbulence
over and downwind of the terrain of all islands. No other AIRMETS
are in effect or expected.

&&

.MARINE...
The tight pressure gradient produced by high pressure north
northeast of the islands will maintain these ongoing moderate to
fresh trade winds through the work week. A Small Craft Advisory
(SCA) remains in effect for the waters surrounding Maui County and
those waters south of the Big Island through Friday afternoon to
account for locally strong winds. The areal coverage of this SCA
may need to be expanded westward by Tuesday night.

The current southwest to south swell will continue to fade. Low
background southerly swells will come through over the next
several days and hold below normal surf along south facing
shores. North facing shore surf will remain flat, only to benefit
from some trade wind wave wrap through the remainder of the week.
The only notable surf will be along east facing shores where
persistent moderate to locally strong trades keep surf heights up
to near summertime averages.

&&

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

&&

DISCUSSION...Bohlin
AVIATION...Jelsema
MARINE...Blood