Honolulu, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

465
FXHW60 PHFO 130654
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
854 PM HST Tue Nov 12 2024

.SYNOPSIS...

Breezy trade winds will strengthen and become windy through the
end of the week. Showers will focus along windward mauka exposures,
reaching leeward sides of the smaller islands as winds strengthen.

&&

.DISCUSSION...

A strong 1035 mb high north of the state is generating robust
trade winds across the islands today. 00Z soundings at Hilo and
Lihue show a strong 7000 ft inversion in place across the area.
Satellite and radar show a band of showery clouds over and just
upstream of the state this evening. Expect mostly light to
moderate showers to quickly pass mainly for windward slopes of
the island tonight into Wednesday, with isolated showers leeward.
Trade wind showers are likely to increase again Wednesday night
into Thursday.

The high to the north will strengthen as a front weakens and is
pushed southward. Trade winds speeds will begin to increase Wednesday
and will continue to strengthen through the end of the week.
Winds are forecast to peak Friday through Saturday with some
portions of the state reaching advisory levels as early as
Thursday. Latest model guidance is hitting at winds reaching
advisory levels late Wednesday. Will continue to monitor and make
a determination in the next package. Peak winds may coincide with
with the arrival and departure of the remnants of the dissipated
front mentioned above. An increase in cloud cover and showers is
expected as this feature passes through with both windward and
leeward sides of the islands. Wind speeds will slowly taper down
Sunday into Monday (but still remain fairly breezy) with showers
focusing windward and mauka.


&&

.AVIATION...
Breezy easterly trades will gradually strengthen through Wednesday.
Clouds and showers will favor windward and mauka areas, with
increased showers expected tonight. Expect brief periods of MVFR
CIGS/VSBYS within passing showers. Otherwise, VFR conditions will
prevail, including at the TAF sites.

AIRMET Tango for moderate low-level turbulence will persist over
and downwind of all island terrain.

AIRMET Sierra will likely be needed later tonight for many
windward and mountain areas due to the expected increase in
showers.


&&

.MARINE...
A strong high pressure system will build in north of the Hawaiian
Islands over the next several days. Expect strong and gusty trade
winds tonight, possibly reaching gale force levels in the windier
channels from Thursday into the weekend. The Small Craft Advisory
remains in effect for all coastal waters due to these strong
trade winds and corresponding high seas. A Gale Watch may be
needed for the second half of this week, for the windier waters
near Maui and the Big Island, in anticipation of even stronger
wind speeds.

Existing medium to long period northwest (320 degrees) swell
energy will be reinforced by a larger, long period northwest
(320-330) swell later tonight. This swell is forecast to peak well
above advisory levels threshold for north and west facing shores
by Wednesday morning, potentially nearing High Surf Warning
thresholds by Wednesday night, and then decreasing on Thursday.
This swell will mix with a small, long period north-northwest
(340-350) swell that will also peak tonight into Wednesday. A High
Surf Advisory starting Wednesday at 6 AM HST was issued for north
and west facing shores of Niihau, Kauai, Oahu, and Molokai, as
well as north facing shores of Maui.

Rough and choppy surf along east facing shores will gradually become
more elevated during the second half of the week as trades become
stronger locally and upstream of the islands. Surf along east facing
shores is expected to build to the advisory level Thursday into Friday,
then hold into the weekend. This high surf will increase the threat
of coastal inundation impacts along east facing shores from
Thursday through next week Monday.

Surf along south facing shores remains small through the period, except
for a small bump expected by Wednesday.

Peak monthly tides are forecast from Nov 14th to 18th. These high
tides will combine with elevated seas due to strong trades and slowly
fading northwest/north swells to exacerbate coastal inundation impacts,
particularly for vulnerable locations during early morning high tides.


&&

.FIRE WEATHER...
Trade wind speeds are forecast to exceed sustained 20 mph at
Honolulu airport Friday and Saturday, with higher speeds in more
exposed areas around the state. It is also possible for winds to
also reach 20 mph on Thursday while ramping up, and on Sunday
while trending down. KBDI is currently 672 today. The limiting
factor will be relative humidity, which is expected to stay in the
upper 40s to lower 50s as around Honolulu. Other leeward areas
that may reach low 40 relative humidity is leeward Kauai, Maui and
the Big Island. While a Fire Weather Watch or Red Flag Warning is
not anticipated at this time, conditions may come close on
Thursday or Friday afternoon. Will be monitoring for any changes
in this forecast in the coming days.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...

High Surf Advisory from 6 AM Wednesday to 6 PM HST Thursday for
north and west facing shores of Niihau, Kauai, Oahu, Molokai and
for north facing shores of Maui.

Small Craft Advisory until 6 AM HST Thursday for all Hawaiian
waters-


&&

$$


DISCUSSION/FIRE WEATHER...Almanza
AVIATION...Powell
MARINE...Bohlin