852
FXHW60 PHFO 130701
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
901 PM HST Fri Jul 12 2024

.SYNOPSIS...
A large area of high pressure generally north of the Hawaiian
Islands will hold the next several days. This will maintain the
ongoing typically dry summertime trade wind pattern. Thicker more
areal coverage clouds and more frequent showers will also continue
to favor windward exposures and mauka zones. The next decent
chance of more island-wide rain may be early next week in response
to a vicinity upper level disturbance northeast of the state.


&&

.DISCUSSION...
There is little variance in forecast philosophy under this near
static Central Pacific synoptic pattern. Summertime dry trades
persist as a pair of high pressure centers northwest and northeast
of the islands drive primarily fresh to locally strong winds.
Relatively lower inversion 5-6k foot heights resulting in a more
shallow boundary layer, in tandem with very dry mid to upper level
%RHs advecting across the chain, nearly guarantees a stable
enough island environment that will generally support windward and
mauka cloudier skies and more frequent showers. The usual suspect
caveats of cloudier, slightly more wet afternoon Kona and Ka`u
slope conditions with occasional leeward sprinkles and partly
cloudy skies riding over local area ridgetops still apply.

The development of an upper level disturbance forming in the
middle of northern ridging will be the impetus of gradually
weakening trades. The reflection of lowering surface pressure,
along with the proximity of a subtropical jet, may work in favor
of increasing more areawide pockets of better organized early week
shower activity. The main question marks to increased shower
activity will be whether or not there will 1) be ample column
moisture within a deepened, marginally-destabilized boundary
layer and 2) the location of the upper disturbance in relation to
the islands.


&&

.AVIATION...

Breezy to locally windy trades will continue for the next few
days. SHRA and low cigs will favor windward and mauka locations.
Brief MVFR conds are possible in any SHRA. VFR conds should
generally prevail.

AIRMET Sierra for mtn obsc remains in effect for N thru SE
sections of Kauai, Oahu, Molokai, Maui and the Big Island.

AIRMET Tango for mod low-level turb lee of island terrain will
remain in effect for the next several days due to the strong
trades.


&&

.MARINE...
A strong high pressure ridge north of the Hawaiian Islands will
keep fresh to strong trade winds in the forecast through the
weekend and into much of next week. Typical windier channel areas
will see wind speeds near gale forecast at times with seas
approaching 10 foot advisory levels. A Small Craft Advisory (SCA)
remains in effect for all Hawaiian Coastal Waters through Sunday
afternoon. A subtle decrease in the trade winds are forecast by
early next week. The SCA winds will linger in more than just the
typical windier waters for most of next week.

Due to the strong trade winds upstream of the state, surf along
east facing shores will remain rough and choppy through early
next week. A downward trend is possible around midweek as the
upstream fetch weakens and the local trades begin to ease.

Surf along south facing shores will remain up as overlapping
south-southwest swells move through. A more significant south
swell will gradually fill in late Saturday night into Sunday,
then likely reach the advisory level late Sunday through Monday.
A gradual downward trend is expected Tuesday through midweek.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Saturday for all Hawaiian
waters-


&&

$$


DISCUSSION...Blood
AVIATION...Walsh
MARINE...Bohlin