195
FXHW60 PHFO 191343
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
343 AM HST Fri Jul 19 2024

.SYNOPSIS...
Moderate trade winds will continue over the next few days, with
breezy to locally windy trades returning by early next week. A dry
and stable air mass across the region will help to limit windward
and mauka showers over most islands today. A weak disturbance
riding in on the trades will increase clouds and shower activity
tonight into Saturday, with another weak disturbance moving across
the islands next Tuesday. No significant rainfall is expected
from either disturbance, but it should provide some beneficial
rain for windward and mauka areas.

&&

.DISCUSSION...
A ridge of high pressure far north of the state will maintain
moderate trade winds over the next several days. Meanwhile, radar
and satellite imagery continue to show brief passing showers
moving into windward areas of Maui, Molokai, and Oahu early this
morning under partly to mostly cloudy skies. Overall, expect fair
weather to continue through today with light showers over windward
and mauka areas and mostly dry conditions across the leeward side.

The latest 12Z surface analysis from HFO shows a weak trough
approximately 225 miles east of the Big Island. Guidance continues
to show this trough moving across the state tonight into Saturday
resulting in an uptick in windward and mauka showers, especially
across Maui and the Big Island. The latest CIMSS MIMIC layer PWAT
shows a blob of moisture around 1.6 inches east of the state this
morning with modeled PWATs around 1.7 inches as the trough inches
towards the Big Island. Periods of moderate showers are possible
over windward Big Island and east Maui, with 1 to 2 inches of
rain possible along the windward slopes of the Big Island on
Saturday. Overall, just some showery weather is expected and it
should not be a flooding concern.

Showers will generally increase over the western half of the
state late Saturday into Sunday with scattered showers over
windward areas. Leeward areas should see an increase in cloud
cover, with some passing showers. Drier conditions return by late
Sunday with breezy trades expected by Monday. Breezy to locally
windy trade will then continue through much of the upcoming week
as high pressure strengthens far northeast of the state.

Another disturbance is expected to move across the state on
Tuesday, with model PWATs around 1.8 inches. This system should
bring more widespread clouds and showers to windward and mauka
areas of all islands. With the stronger trades in place expect
some of these showers to spillover into leeward areas at times.
Expect a return to more typical trade wind weather conditions
behind the disturbance with strong trades continuing through the
end of the upcoming week.

&&

.AVIATION...
Moderate to locally breezy trades will continue through the rest
of the week and into the weekend. SHRA and low cigs will favor
windward and mauka areas and could bring brief periods of MVFR.
Otherwise, VFR should prevail.

No AIRMETs are currently in effect.

&&

.MARINE...
A high pressure system and weak trough far north of the Hawaiian
Islands will keep moderate easterly trade winds blowing across the
region into Sunday morning. Trade winds will begin to strengthen
into the fresh to locally strong range starting Sunday afternoon
as the high center, currently northwest of the state, drifts east
and strengthens. Trade wind speeds will be strong enough to
support Small Craft Advisory conditions over the windier waters
and channels near Maui and the Big Island from Sunday evening
through much of next week.

Slightly elevated surf along south facing shores will ease below
average today. Background south swell energy pulses are forecast
to continue with surf remaining below average. Small, choppy surf
expected for east facing shores for the next several days due to
to continued trade winds. Surf then becomes increasingly rough
along east facing shores as locally strong trades return early
next week.

Spring tides peak this weekend, and local tide gauges indicate
water levels already running above guidance. Water levels are
currently running at least 1 foot higher than the Mean Higher High
Water (MHHW) threshold at Hilo, Kahului, and Honolulu and are
approaching the 1 foot threshold at Lihue. Therefore, a Coastal
Flood Statement remains in effect through the weekend.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Ahue
AVIATION...Walsh
MARINE...Bohlin