322
FXHW60 PHFO 281305
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
305 AM HST Fri Jun 28 2024

.SYNOPSIS...
A high pressure ridge will remain in place north of Hawaii into
next week, producing moderate trade winds through the weekend, and
then strengthening into the moderate to breezy range from Monday
onward. Passing showers are expected to mainly affect windward
and mountain areas, favoring the overnight to early morning hours.
An upper level low will drift from east to west over the islands
this weekend, likely increasing shower activity as it passes
through the state. Isolated thunderstorms are possible over the
interior Big Island on Friday and Saturday afternoons, and near
Kauai this weekend.

&&

.DISCUSSION...
A band of unstable low clouds will continue to enhance clouds and
showers over the islands through the morning and afternoon hours.
The water vapor channel satellite imagery continues to show an
upper level low roughly 550 miles northeast of Hilo, Hawaii. This
low will slowly drift westward across the island chain through the
weekend, enhancing trade wind showers as it passes through the
state.

Global weather models continue to show a slight weakening of the
ridge induced trade winds through the weekend, as the upper low
passes over the region. Isolated thunderstorms are possible over
the Big Island interior on Friday and Saturday afternoons, and
then near Kauai from Saturday night to Sunday.

The ridge north of the island chain will then strengthen after
the upper low weakens and drifts away from the islands on Monday,
increasing trade winds into the moderate to breezy range from
Monday onward. The strengthening ridge will also keep the trade
wind thermal inversion at more stable and at lower heights from
5,000 to 6,500 fee next week, limiting shower activity for most of
the days.

&&

.AVIATION...
Moderate trades are expected to continue across the island chain
through the weekend. Showers and low clouds embedded in the
trades will bring brief periods of MVFR conditions over windward
and mauka locations. Otherwise, VFR conditions should prevail.

AIRMET Sierra is in effect for tempo mountain obscuration across
the windward portions of the island chain early this morning as a
band of low clouds and showers moves in from the east. In
addition, an upper-level low is forecasted to approach the islands
this weekend and is expected to increase shower coverage. As such,
AIRMET Sierra may be needed periodically throughout the weekend.

&&

.MARINE...
High pressure north of the state will maintain moderate to fresh
trade winds through the weekend. The trades are expected to
strengthen back to fresh and strong levels early next week, and a
Small Craft Advisory will likely be required for the typically
windy waters around Maui and the Big Island.

A series of south swells will keep south shore surf near the
summertime average through Saturday. Surf will lower below normal
levels much of next week.

Typical mostly flat summertime conditions will continue along
prevail north facing shores through late next week.

East shore surf will remain well below normal through the weekend,
then trend up and closer to seasonal levels next week as the
trades strengthen over and upstream of the islands.

&&

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

&&

$$

DISCUSSION...Bohlin
AVIATION...Farris
MARINE...Jelsema