Area Forecast Discussion
Issued by NWS Honolulu, HI

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000
FXHW60 PHFO 300621
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
821 PM HST Thu Jul 29 2021

.SYNOPSIS...
Dry and breezy trade wind conditions are expected through the
weekend and into early next week. The best chance for showers will
be through the overnight and early morning periods over windward
and mauka locations.

&&

.DISCUSSION...
Guidance remains in good agreement and depicts the subtropical
ridge strengthening to the north over the weekend. This combined
with rising upper heights and drier air moving in will support
more of a suppressed and stable environment. Any showers that do
development will favor windward and mauka areas, leaving little
hope for reaching our parched leeward areas where drought
conditions continue. The exception will be over the Kona slopes of
the Big Island, where isolated afternoon showers are possible
each day. Similar conditions will carry into next week.

&&

.AVIATION...
Surface high pressure to the north of the islands will maintain a
moderate to locally strong trade wind flow into tomorrow. AIRMET
Tango remains in effect for low level mechanical turbulence to the
lee of the mountains on all islands. Anticipating this AIRMET to
remain in place over the next several days. Expect clouds and
showers to remain focused over windward and mountain areas in the
trade wind flow. Brief MVFR conditions are possible, but not
anticipating any significant mountain obscuration.

&&

.MARINE...
High pressure far north of the state will slowly drift eastward
and build from Friday into the weekend. Trade winds will begin to
gradually strengthen through the weekend. Widespread strong
trades are expected over the Hawaiian waters by Sunday. The Small
Craft Advisory will likely need to be expanded in coverage by this
weekend with increasing trade winds.

Surf along east facing shores will remain small through Friday,
then trend up through the weekend in response to strengthening
trades locally and upstream of the Hawaiian Islands.

Southerly swell activity will remain rather low for this time of
the year with just background swells expected from the south and
southeast. Nearly flat conditions will continue for north and west
facing shores into early next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Sunday for Oahu Leeward
Waters-Kaiwi Channel-Maui County Windward Waters-Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

&&

$$

DISCUSSION...Gibbs
AVIATION...Thomas
MARINE...Bohlin


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