672
FXHW60 PHFO 030704 CCA
AFDHFO

Area Forecast Discussion...CORRECTED
National Weather Service Honolulu HI
904 PM HST Thu May 2 2024

.SYNOPSIS...
The high pressure center far north of the Hawaiian Islands will
build through Friday producing breezy trade winds across the
region. Breezy trade wind weather will last into the first half of
next week. An upper level disturbance will enhance passing
showers in the forecast into early next week, favoring windward
and mountain areas in the overnight to early morning hours. A few
of the stronger showers will drift into leeward areas. Long range
guidance shows an old frontal band moving into the islands from
the northeast next week Wednesday. This cloud band may bring
another brief round of wet weather to all islands from Wednesday
morning into next week Thursday.

&&

.DISCUSSION...
Satellite water vapor channel imagery this evening shows an
unstable upper low spinning roughly 500 miles northwest of Kauai
with an upper trough and subtropical jet stream over the Hawaiian
Islands. This upper level disturbance will continue to enhance
trade wind showers across the state into the first half of next
week. Upper level cirrus clouds may enhance sunrise and sunset
colors through Monday.

The latest forecast guidance shows two high pressure systems in
the Central Pacific consolidating into one high center. This high
center is building slightly just north of the Hawaiian Islands on
Friday. The strengthening high pressure ridge will increase trade
winds into breezy levels from Friday into Monday. By Monday
afternoon the high center drifts eastward away from the islands
with a frontal trough moving into the Central Pacific basin. This
change in large scale pressure patterns near the islands will
decrease trade wind speeds back to more moderate levels from
Tuesday onward.

Expect continued enhanced showers across the state as the upper
level disturbance slowly drifts eastward across the island chain.
Most of the rainfall amounts will favor windward and mountain
areas with decreasing shower activity over zones on the leeward
sides of each island. These showers will tend to increase during
our diurnal rainfall maximum in the overnight to early morning
hours.

In the extended forecast our long range guidance suggests a long
band of unsettled clouds, remnants of an old cold front, drifts
into the islands on the moderate trade winds from Wednesday
morning into Thursday. This band produce wet weather over all
islands for an 18 to 24 hour time period next week. The highest
amounts will tend to favor windward areas, however many leeward
sites may also see measurable rainfall totals with this system.

&&

.AVIATION...
Moderate to breezy E trades will continue to strengthen through
Friday as high pressure builds in from the NE. A moisture plume
riding the trades should bring in SHRA and MVFR conds to windward
and mauka locations. While a few SHRA and lowering cigs/vsbys
could reach leeward side, they look to be brief even with a slight
increase in coverage. VFR conds will generally prevail.

AIRMET Sierra is in effect for mtn obsc for windward and mauka
portions of the island chain as an increase in SHRA and low
cigs/vsbys increase for the overnight hours.

AIRMET Tango is in effect for mod turb below 080 downwind of
island terrain.

AMD NOT SKED in for Midway due to missing wind speed and
direction.

&&

.MARINE...
Moderate to locally strong easterly trade winds will gradually
strengthen through Friday, becoming fresh to locally strong as
high pressure builds and settles far north of the state. These
stronger trades will continue through the weekend. A Small Craft
Advisory (SCA) remains in effect for typical windy waters around
Maui and the Big Island through early Monday morning. Additional
waters will likely be added to the SCA in the next package as
trade winds continue to strengthen and expand in coverage across
additional coastal zones.

Tiny surf will persist along north and west facing shores through
much of the day on Friday. A small, long period northwest swell
is expected to fill in late Friday and peak Saturday, bringing
small surf along north and west facing shores. Another small, long
period northwest swell will fill in late Sunday, maintaining
small surf along north and west facing shores into early next
week. Small background south swells will continue into Saturday,
providing tiny surf for south facing shores. A small, long period
south swell may arrive Sunday providing a boost in surf along
south facing shores into early next week. Surf along east facing
shores will gradually become more rough and choppy into this
weekend as stronger trades return.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Monday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

&&

$$

DISCUSSION...Bohlin
AVIATION...SMW
MARINE...Almanza