Area Forecast Discussion
Issued by NWS Honolulu, HI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
000
FXHW60 PHFO 230642
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
842 PM HST Fri Mar 22 2024

.SYNOPSIS...

Breezy northeast trade winds will continue through next week
focusing clouds and showers over windward and mauka areas,
periodically reaching leeward areas.

&&

.DISCUSSION...

Water vapor imagery shows an upper level trough axis across the
eastern part of the state this evening. Meanwhile, a 1031 mb
surface high is centered around 900 miles to the northeast driving
breezy trade winds across the islands. Visible and infrared
satellite shows an incoming batch of showers just upstream of the
smaller islands, and guidance shows these showers filling in
across the state rest of this evening into Saturday. While the
focus will be windward and mauka area, some showers will reach
leeward sides of the smaller islands due to the breezy winds. The
upper trough may also enhance some of these showers into early
Saturday morning.

The upper trough will slide east of the state Saturday resulting
in increasing stability. Wind speeds are expected to gradually
increase through Saturday and maintain into early next week as the
high to the northeast strengthens slightly before slowly shift
east. Low clouds and showers will continue track across the
islands with the breezy winds, focusing along windward and mauka
and occurring during the overnight and early morning hours.
Leeward sides will also continue to see period showers at times.

As the upper level trough slides east, an upper level low will
close off and move south of the state. This gradient will
strengthen winds to advisory or low-level warning levels for the
summits of the Big Island Saturday into Sunday. The pattern will
also aid in advecting moisture in the mid and high levels,
increasing cloud and possibly shower coverage over the state
beginning with the Big Island Saturday then reaching Kauai
Monday and lingering through by mid- week. At the surface, breezy
trade winds will persist through next week with slight
modifications as the high to the northeast weakens Tuesday, but
will quickly be replaced by another high by Wednesday. Showers
will continue to focus along windward and mauka areas with a few
showers reaching leeward areas, especially early next week as
moisture levels increase.

&&

.AVIATION...
High pressure to the northeast, with an associated ridge north of
the state will maintain breezy trade winds through Saturday, with
showers focused over windward and mountain areas. Brief MVFR
conditions are possible in clouds and showers, mainly during the
overnight and early morning hours.

AIRMET TANGO remains in effect for mechanical low-level
turbulence over and downslope of the mountains. Expect this airmet
to remain in place through the weekend.

AIRMET SIERRA was recently cancelled for the Big Island, but may
be needed overnight depending on the extent of showers moving in
on the trade wind flow for any of the islands.

&&

.MARINE...

Surface high pressure north of the state will gradually
strengthen and drift east over the next couple of days, resulting
in persistent fresh to strong trade winds. Another high will
quickly build north of the state early next week which will
keep strong trades in the forecast through next week. A Small
Craft Advisory remains in effect for all Hawaiian waters through
Sunday afternoon.

An incoming small to moderate long period northwest swell will
peak Saturday. This swell will elevate north and west facing
shore surf this weekend, though it will likely remain below High
Surf Advisory (HSA) levels. However, a larger northwest swell will
arrive Sunday, and will likely result in HSA level surf for
exposed shores Sunday night into Monday.

Short period easterly wind wave swell will trend upward this
weekend as trade winds gradually increase. South-facing shore
surf will remain at background levels for the next several days.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Sunday for all Hawaiian
waters-


&&

$$


DISCUSSION...Almanza
AVIATION...M Ballard
MARINE...M Ballard


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.