951
FXHW60 PHFO 281946
AFDHFO

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

.SYNOPSIS...
An upper low will approach the islands and bring scattered
enhanced showers and isolated thunderstorms with the focus over
Kauai and afternoons over the interior Big Island. The atmosphere
will stabilize early next week with weather returning to typical
summertime trade winds with passing windward and mauka clouds and
showers.

&&

.DISCUSSION...
Water vapor imagery shows an upper level low centered 550 miles
northeast of Hawaii and approaching. At the surface, high pressure
to the north is driving moderate to locally fresh trade winds.
Visible satellite and radar show an area of showery low clouds
over Maui and Big Island this morning with the trades focusing
them over the windward slopes. Drier weather persists across Kauai
and Oahu this morning with windward clouds. Soundings from early
this morning show weak stability holding on.

The area of clouds and showers will linger through the day over
Maui and Big Island as the trades move it westward. As the Big
Island heats up today, isolated thunderstorms will be possible
across the interior and leeward side. The upper low will approach
Saturday and Saturday night coming close to Kauai before shifting
north away from the area Sunday. The instability will be present
through the whole weekend with 500 mb temperatures around -10 C
to -11 C near Kauai, but moisture won`t be very significant with
model precipitable water values only in the 1.2 to 1.3 inches.
Thus, we are forecasting scattered enhanced showers with isolated
thunderstorms mainly across the northwest end of the state, and
for the interior Big Island. Trade winds will weaken slightly
through the weekend and Monday as the high to the north
temporarily weakens.

The atmosphere will stabilize early next week with weather
returning to typical summertime trade winds with passing windward
and mauka clouds and showers. Most rainfall will occur during the
nighttime hours, but no significant accumulations are expected.


&&

.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 most of the island chain this morning as
a band of low clouds and showers moves in from the east.

An upper-level low is forecast to move over the islands this
weekend, resulting in increased shower coverage and likely need
for AIRMET Sierra 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 by Monday.

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. A small background south swell is
possible towards the middle 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...Foster
AVIATION...TS
MARINE...Kino