FXHW60 PHFO 190650
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
850 PM HST Thu Jul 18 2024

.SYNOPSIS...
Moderate trades will continue over the next few days with breezy
trades returning early next week. Dry and stable air over the
state should limit windward showers over most islands into Friday.
A weak disturbance riding in on the trade winds from the east
will increase clouds and shower activity from Friday night into
Sunday morning. Another weak disturbance will move into the Hawaii
region by next week Tuesday. No significant rainfall is expected
from these disturbances, but it should provide some beneficial
rain for windward areas.

&&

.DISCUSSION...
A ridge of high pressure far north of the state will maintain
moderate trade winds over the next several days. Overall, fair
weather will continue through most of the day Friday with mainly
light showers over windward and mountain areas and mostly dry
conditions over leeward areas.

Starting late Friday, a weak trough will approach the state from
the east and will likely bring an increase of showers, especially
Friday night through Saturday for the eastern half of the state.
Latest CIMSS MIMIC precipitable water shows a blob of moisture
currently located near 150W with precipitable water values of
around 1.8 inches. Periods of moderate showers will be possible
over windward Big Island and east Maui, with 1 to 2 inches of rain
possible especially along the windward slopes of the Big Island
on Saturday. Overall, just some showery weather is expected and it
will not be a flooding concern.

Showers will generally increase over the western half of the
state as well late Saturday through Sunday morning with scattered
showers over windward areas. Leeward ares should see an increase
of cloud cover, with some passing showers occasionally. Drier
conditions will begin to return by Sunday afternoon with stronger
trades. Breezy to strong trade winds will return by Monday and
will likely persist through the first half of next week.

Latest guidance is in fairly good agreement with a plume of
moisture (precipitable water values of around 1.8 inches) moving
in across the state on Tuesday. With the breezy to locally strong
trade winds in place, moderate showers will likely impact windward
and mountain areas with some scattered showers making its way
over to leeward areas. The increase of showers will likely be
short-lived as drier conditions begin to return by Thursday.

&&

.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 by Friday. Background south swell energy pulses are
forecast from Friday onward with surf remaining below average
throughout this time. 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