116
FXHW60 PHFO 141949
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
949 AM HST Sun Jul 14 2024

.SYNOPSIS...
A large area of high pressure north of the Hawaiian Islands will
hold through early Monday, maintaining a dry trade wind pattern.
Light windward and mauka showers will primarily occur during
overnight through early morning hours each day. A mid/upper level
disturbance developing northeast of the state this week will
weaken trades from Tuesday onward.

&&

.DISCUSSION...
No meaningful changes have been made to the forecast this morning
as high pressure still remains anchored far north of the state.
This high is resulting in stable and mostly dry conditions across
the islands. It is also producing breezy easterly trade winds,
which will continue into Monday morning. Latest satellite and
radar imagery shows stratocumulus clouds moving into the windward
sections of the islands with very little rainfall. Early morning
12z soundings from Lihue and Hilo depicted inversion heights
around 5,000 to 6,000 feet with ample dry air aloft above the
inversion. For the rest of the day, expect this dry trade wind
pattern to continue, with any light showers favoring windward and
mauka areas. Additionally, typical increases in cloud cover for
leeward sections of the Big Island can be expected from late
morning through the afternoon.

Models remain consistent in that a trough aloft and eventual
mid/upper low will develop northeast of the state beginning late
Monday. This feature is expected to remain quite a distance off
to the northeast of the state through much of the week. The most
noticeable change for island weather will be in the form of weaker
trade winds than we have experienced over the past several days.
Otherwise, as the weak feature aloft drifts closer to the island
chain during the latter portion of the week, a subtle increase in
windward and mauka shower activity will be possible. Inversion
heights are forecast to increase by next weekend, especially over
the eastern end of the state. Therefore, any increase in shower
activity late this week would be most likely across Maui County
and the Big Island, though any significant accumulations appear
unlikely for at least the next seven days.

&&

.AVIATION...
Breezy to locally windy trades will continue over the next few
days. Mainly light showers and periodic low ceilings will favor
windward and mauka locations with a few showers making it leeward.
Some brief MVFR conds are possible in passing showers, otherwise
VFR conditions will prevail.

AIRMET Sierra is in effect for mountain obscuration for N through
E sections of Maui and Molokai. Conditions have improved elsewhere,
and will do so for the remaining islands later this morning. Low
cigs and a slight increase in SHRA are expected tonight into the
morning hours on Monday.

AIRMET Tango for mod low-level turb lee of terrain is in effect
and will likely be needed for the next several days due to the
strong trades under a strong inversion.

&&

.MARINE...
Broad high pressure north of the islands will maintain fresh to
strong trade winds for the next several days. A Small Craft
Advisory (SCA) is in effect for the typically waters around the
Big Island and Maui County, while winds elsewhere are at
borderline SCA strength. With little change expected during the
next few days, the SCA will likely be extended through at least
Tuesday. A decrease in trade winds Wednesday through Friday may
allow the SCA to be cancelled.

A High Surf Advisory is in effect for south facing shores as a
long period south swell builds today. Nearshore PacIOOS buoys have
been measuring the rising swell from about 190 degrees at 2.5 to 3
feet 17 seconds this morning. Offshore NOAA buoys and data from
several days prior at the PacIOOS Samoa buoy continue to suggest
that the swell will peak tonight and Monday. South shore surf will
fall below the advisory level by Tuesday, then gradually decline
through Friday.

Rough east shore surf will remain slightly above July average
through Monday. The short period wind wave energy will slowly
decline as trades upstream of, and eventually over, the islands
weaken. East shore surf will fall below average by Wednesday and
will decline further through Friday. No significant source of
northerly swell is noted.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 PM HST Monday for Niihau-Kauai
Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai
South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai Leeward
South-Lanai Leeward-Lanai South-Maui Central Valley South-South
Maui/Upcountry-South Haleakala-Big Island South-Big Island
Southeast.

Small Craft Advisory until 6 PM HST Monday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

&&

$$

DISCUSSION...Vaughan
AVIATION...TS
MARINE...Wroe