892
FXHW60 PHFO 181939
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
939 AM 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 today 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. Showers and low ceilings will
favor windward and mauka areas and could bring brief periods of
MVFR. Otherwise, VFR should prevail.

No AIRMETs are currently in effect.


&&

.MARINE...
Moderate trades continue through the week in response to weak
troughing positioned northeast of the islands. Locally strong
trades and potential Small Craft Advisory conditions then return
early next week as high pressure reestablishes north of the
islands.

Surf along south facing shores persists today then eases below
average by Friday. Background S swells are then expected Friday
onward with surf remaining below average throughout this time.
Small, choppy surf expected for east facing shores for the next
several days in response to weakening trades. Surf then becomes
increasingly rough as locally strong trades return early next
week. Elsewhere, no noteworthy swells expected.

Spring tides peak this weekend, and local tide gauges indicate
water levels already running above guidance. Water levels may
reach or exceed the 1 foot Mean Higher High water (MHHW) threshold
as early as Friday afternoon causing minor flooding along low
lying coastal zones. This may prompt the issuance of a Coastal
Flood Statement (CFS) during future forecast cycles. The
likelihood of water levels exceeding the 1 foot threshold is high
from the Big Island to Oahu Friday into Monday. However, there is
a chance the water level could reach the 1 foot threshold around
Kauai as well.


&&

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

&&

$$


DISCUSSION...Kino
AVIATION...Farris
MARINE...JVC