283
FXHW60 PHFO 051942
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
942 AM HST Sun May 5 2024

.SYNOPSIS...
Breezy trade winds will continue into Monday, then decrease to
moderate speeds late Monday into Tuesday. An upper-level disturbance
passing through the islands will keep enhanced trade showers in
the forecast through Monday. Additional bands of moisture, along
with another upper disturbance, will keep generally wet weather in
place for all islands through next week.

&&

.DISCUSSION...
Water vapor satellite imagery this morning shows a weakening upper-
level low just west of Kauai, drifting slowly eastward. A portion
of the subtropical jet stream is also set up over the islands today,
which will result in strong southwest winds aloft over the Big Island.
A Wind Advisory is now in effect for the summits of Mauna Kea and
Mauna Loa through this afternoon. The strong summit winds will diminish
later this evening through tonight.

At the surface, a 1030 mb high remains far north of the island chain
and will continue to produce breezy easterly trade winds across the
state into Monday. By Monday afternoon trade wind speeds transition
to more moderate levels as the high drifts eastward away from the
state. Expect moderate easterly trade winds to continue through the
rest of the week. Current visible satellite and radar imagery show
scattered low clouds and showers moving into windward areas on the
trades, with some showers making it over to leeward sides at times.

Wetter than normal conditions remain in the forecast for all islands
through much of this week. Enhanced showers will continue into Monday
as the weakening upper level disturbance drifts from west to east
across the island chain. While Tuesday will trend a bit drier, more
wet weather is in store Wednesday into Thursday, as the remnant
moisture from an old East Pacific cold front drifts into the islands
on the trade winds. Another upper-level trough sweeping in from the
north on Thursday and Friday will likely keep enhanced showers in
the forecast into next weekend.

&&

.AVIATION...
Breezy easterly trade winds will persist into tonight, with
clouds and showers favoring windward and mauka locations. AIRMET
Sierra for tempo mountain obscuration above 2500 feet will
persist over windward portions of each island through the morning
hours, possibly through the rest of the day for windward Big
Island. As the low moves west across the islands tonight into
Monday, clouds and showers are likely to fill in again.

AIRMET Tango is in effect for moderate turbulence below 9000 feet
downwind of island terrain due to the winds. Additionally,
moderate turbulence aloft (FL280-FL350) is expected today.

&&

.MARINE...
A 1030 mb high sitting about 850 nm north of the state is
maintaining fresh to near gale force trade winds, and a Small
Craft Advisory (SCA) is in effect for all waters through tonight.
Trades will gradually ease late tonight through Tuesday as the
high moves eastward. As a result, the SCA will likely be scaled
back to the typically windy waters around the Big Island and Maui
County by Monday and may be dropped entirely late Tuesday or
Wednesday. Expect gentle to locally fresh trade winds to prevail
Wednesday through Friday. In addition, a few heavy showers will be
possible tonight and Monday.

Pulses of south to southwest swell are expected this week, with
High Surf Advisory (HSA) conditions possible by Thursday. In the
short term, the bulk of a south swell will be passing east of
Hawaii, and so far there has not been much sign of a significant
increase in swell energy at the buoys to the south of the islands.
Once this swell reaches the islands, south shore surf may rise to
around May average tonight and Monday, then decline Tuesday and
Wednesday. Forerunners from a larger south-southwest swell will
arrive Wednesday, and surf is expected rise to the HSA level
during the peak of the swell Thursday and Friday.

A pair of small northwest swells will move through over the next
several days. The current swell of around 2 feet at 12 to 13
seconds will decline today, and a reinforcing small swell of
around 3 ft will fill in Monday, peak Tuesday, then decline
Tuesday and Wednesday. Wind-driven waves of around 9 feet at 9 to
10 seconds will maintain rough east shore surf above the May
average into Monday. As trade winds decline early in the week,
these seas will gradually decline to around May average by Tuesday
then drop to below average for the rest of the week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 6 PM HST this evening for Big Island Summits.

Small Craft Advisory until 6 AM HST Monday for all Hawaiian
waters-

&&

$$

DISCUSSION...TS
AVIATION...Foster
MARINE...Wroe