759
FXHW60 PHFO 160153
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
353 PM HST Thu Aug 15 2024

.SYNOPSIS...
Gentle to low end breezy trade winds will occur through the
remainder of the day. Trades will strengthen to more areawide
breezy magnitudes Friday through most of next week. Showers will
typically favor windward and mauka locations, particularly during
the overnight into early morning hours.


&&

.DISCUSSION...
The remnant of what was once T.C. Emilia in the eastern Pacific is
moving across the local western waters as a broad open wave
trough. Subtle mid level cooling brought on by a lingering upper
level trough, its axis orientated from the islands off to the
northeast, along with higher 850-700 mb layer moisture will keep
higher-end windward/higher elevation rain probabilities in place
through late Friday night. Offshore showers will primarily stick
and dump the highest rain amounts over better east to northeastern
exposed windward and mauka locations. Heat of the day interior
(leeward) thicker clouds and increased shower activity (i.e., Big
Island Kona regions) cannot be ruled out where localized afternoon
sea breeze boundaries set up.

Breezy trade winds are expected to return Friday and persist
through next week as the weak open wave trough mentioned above
travels west away from the state and the subtropical high
northeast of the islands fills in and regains better control.
After a relatively drier Saturday, general weak mid-upper level
ridging, with periodic ribbons of passing higher moisture, may
result in increasing shower coverage to begin next week.
Confidence is still shaky on the development of a tropical
depression or cyclone southeast of the islands next week. If a
system does development and move across those waters south of Big
Island next Thursday or Friday, the upcoming late week forecasts
will trend more wet for the eastern end of the state.


&&

.AVIATION...
Moderate to locally breezy trades will deliver low cigs and SHRA
to windward and mauka areas through the forecast period. MVFR
conds can be expected in any SHRA but VFR should prevail.

No AIRMETs are currently in effect. AIRMET Sierra may be needed
for mtn obsc for windward locations particularly overnight and in
the early morning hours with increased SHRA.


&&

.MARINE...
A weak surface trough passing by north of the islands will keep
the trade winds at moderate to locally fresh speeds through this
evening. As the trough exits the area, the trades will begin
strengthening tonight. The trades should strengthen back to
locally strong speeds late tonight, then hold at these levels
through early next week. A Small Craft Advisory (SCA) is in effect
starting midnight tonight for the typical windy waters around
Maui County and the Big Island.

The current small south swell should hold through tonight then
gradually decline the next few days. Small background energy from
the southeast is also possible during the next few days. A more
significant south swell will arrive late Sunday and Sunday night,
peak above the summertime average Monday, then slowly lower
through the middle of next week.

Seasonally flat to tiny surf is expected through early next week
for north facing shores. East shore surf will remain below normal
during the next couple days, then trend higher over the weekend
and rise to near seasonal levels early next week.

The combination of the full moon and water levels running around
0.5 ft higher than normal should produce minor coastal flooding
each afternoon along the shorelines across the state beginning
8/18 and likely continuing through 8/20. A Coastal Flood Statement
will eventually be needed as we get closer to the event.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory from midnight tonight to 6 AM HST Sunday
for Maalaea Bay-Pailolo Channel-Alenuihaha Channel-Big Island
Leeward Waters-Big Island Southeast Waters.


&&

$$


DISCUSSION...Blood
AVIATION...Walsh
MARINE...Kino