152
FXHW60 PHFO 172003
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
1003 AM HST Mon Jun 17 2024

.SYNOPSIS...
A high pressure ridge north of the state will maintain breezy
trade winds through Tuesday with trades strengthening Wednesday
onward. Breezy to strong trade winds are expected Wednesday
through the weekend. A weak upper low over the state will help
produce periods of showers mainly over the windward and mountain
areas through Tuesday. Drier conditions are briefly expected
Wednesday with scattered showers returning Thursday. Remnants of
an old frontal boundary will likely increase shower activity late
Friday into Saturday.

&&

.DISCUSSION...
A weak upper level low over the state has raised the inversion
heights slightly and the 12Z soundings from Lihue and Hilo show
the trade wind inversion just over 7000 ft. With the slightly
higher inversion, we are seeing a little more showers across the
state this morning, but shower intensity remains on the light side
for the most part. For the rest of today and through Tuesday, we
should be in a fairly similar weather pattern with breezy trade
winds and passing showers. Showery activity will be slightly
higher than our typical summer day due to the upper level low,
with some moderate showers possible over windward areas.

As the upper level low gradually moves westward over the next few
days, we should see drier conditions with lower inversions on
Wednesday. Starting Wednesday into Thursday, the high centered far
north of the state will strengthen and will increase the trade
wind speeds. Breezy to strong trades are expected during the
second half of the week and it may even strengthen a little more
this weekend. Overall a windy weekend is expected and it could
reach wind advisory threshold for select areas, especially the
windier zones around Maui County and the Big Island. On Friday,
models are showing moisture associated with an old frontal
boundary riding in with the trade winds, which could produce
showery weather especially across select windward areas late
Friday into Saturday.



&&

.AVIATION...
Breezy easterly trades will continue, with clouds and showers
favoring windward and mauka locations. Periods of MVFR conditions
will impact these windward sections mainly during the overnight to
early morning hours. Otherwise, VFR conditions will prevail.

AIRMET Sierra for tempo mountain obscuration is in effect for most
windward areas. Conditions should improve later this morning.

If winds increase under the strong tradewind inversion today,
AIRMET Tango for low level turbulence lee of the island terrain
may be needed.


&&

.MARINE...
A high pressure ridge will remain north of the area and will
gradually strengthen during the second half of the week. Moderate
to locally strong trade winds are expected through Tuesday as a
Small Craft Advisory (SCA) is currently in effect for the typical
windier waters around Maui County and the Big Island. Trade winds
look to strengthen across all waters as the SCA is likely to be
expanded to add the waters around Kauai and Oahu on Wednesday
through potentially the end of the week.

The current south swell will continue to slowly fade. For the
rest of the week, expect only background small, medium to long
period, south to southeast swell energy moving through the local
waters.

Weak lows continue to sweep across the northwest Pacific as north
facing shores will remain tiny to small with background energy
through the week. Surf along east shores will become increasingly
rough and choppy from Wednesday onward as the trade winds strengthen
across the state.

&&

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


&&

$$


DISCUSSION...Kino
AVIATION...Farris
MARINE...Shigesato