837
FXHW60 PHFO 100145
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
345 PM HST Tue Jul 9 2024

.SYNOPSIS...
Seasonable trade winds will be breezy to windy through next weekend,
delivering brief showers, mainly to windward areas. In the short
term, trade showers are expected to be fewer than normal, with
increased shower coverage possible later in the week as a trough
aloft moves over the area from the east.

&&

.DISCUSSION...
Seasonable trade wind weather will prevail for the foreseeable
future, with breezy to periodically windy trades supported by a
persistent surface ridge far N of the islands. The trade winds will
deliver brief showers, mainly to windward areas, while most leeward
areas will remain dry. In the short term, trade showers are expected
to be fewer than normal, with increased shower coverage possible
later in the week as a weakening mid-level trough moves over the
area from the E.

Latest visible satellite images show little in the way of low clouds
approaching most islands from the E, while orographic lift is
supporting some low cloud development over the windward slopes of
all islands. Therefore, a relatively dry evening is expected, with a
typical diurnal/overnight increase in clouds and showers leading to
a typical increase in windward showers overnight. An exception is a
recently developed cluster of primarily stable low clouds that is
poised to move into windward Big Island this evening, likely fueling
an increase light showers.

A westward-moving mid-level trough is located E of the area along
145W, while a mid-level ridge is located N of Kauai. The resultant
gradient is bringing increased NE-E winds to the Big Island Summits,
where a Wind Advisory is posted. Winds may remain elevated through
Wednesday as the trough approaches. Warm mid-level temperatures will
persist over the islands through Thursday supporting a low and
strong inversion and limited shower coverage. The approach and
passage of the trough will bring some mid-level cooling Thursday
night through Friday night, potentially leading to an increase in
trade wind showers.

&&

.AVIATION...
Breezy to locally windy trade winds will continue for the next
couple of days. Low clouds and showers will favor over windward and
mauka areas, with a slight uptick in activity during the overnight
and early morning hours. Expect mainly VFR to prevail with brief
MVFR under passing showers.

AIRMET Tango for mountain lee turbulence will remain in effect for
the next couple of days.

&&

.MARINE...
A broad ridge north of the state will strengthen during the next
several days. Expect winds to become locally strong over the next
couple of days and then remain elevated into the weekend. The Small
Craft Advisory remains in effect for the typical windier areas
around Maui and the Big Island, along with the Pailolo Channel and
the Maui windward waters. Additional areas may need to be added as
the ridge continues to strengthen and additional observations become
available.

Small SSE swell will slowly decline this week. However, the existing
small, long period SSW swell will help maintain small surf along
south facing shores for much of the week. A storm- force low
southeast of New Zealand will send a decent run of south swells
beginning this weekend. Resultant surf may reach the advisory
threshold of 10 feet along south facing shores during its peak
Sunday into Monday. Choppy surf along east facing shores will
steadily increase during the middle to second half of the week in
response to the building trade winds upstream of the state. Surf
along north and west facing shores will remain nearly flat.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 6 AM HST Wednesday for Big Island Summits.

Small Craft Advisory until 6 AM HST Thursday for Kaiwi Channel-
Maui County Windward Waters-Maalaea Bay-Pailolo Channel-
Alenuihaha Channel-Big Island Leeward Waters-Big Island
Southeast Waters.

&&

$$

DISCUSSION...Birchard
AVIATION...Ahue
MARINE...JVC