High Surf Warning 7, NWS Honolulu, HI

Area Forecast Discussion
National Weather Service Honolulu HI
324 PM HST Tue May 31 2022

.SYNOPSIS...
Moderate trade winds will continue through Thursday, with clouds
and mainly light showers favoring windward and mauka locations.
Trade winds will trend down Friday through the weekend,
potentially enough for a localized land and sea breeze regime to
dominate over leeward areas. Stable and somewhat dry conditions
will lead to light rainfall accumulations.

&&

.DISCUSSION...
Moderate, stable, and somewhat dry trade winds will remain in
place through Thursday as a strengthening surface ridge sits
north of the islands. Meanwhile, a ridge aloft will maintain
stability with a solid inversion based between 5,000 to 7,000 ft,
and moisture within the trade wind flow will hold near or below
seasonal average. The result will be modest windward rainfall
favoring nights and mornings as shallow pockets of moisture ride
along the trade wind flow. Most leeward areas will remain dry,
while the leeward slopes of the Big Island experience afternoon
clouds and scattered showers followed by overnight clearing.

Trade winds will ease Friday into the weekend as the ridge is
weakened and nudged southward, and a ridge aloft will maintain
stability. Trades may become weak enough for a land and sea
breeze regime to dominate over leeward areas, but given the stable
and somewhat dry conditions, no increase in rainfall is expected.
Trades should gradually rebuild next week.

&&

.AVIATION...
High pressure to the north of the islands will maintain moderate
trade winds and a stable airmass through Monday. VFR conditions
will prevail with some pockets of MVFR expected in passing clouds
and showers, primarily impacting the windward and mauka areas in
the trade wind flow. No AIRMETs are currently in effect, and none
are expected overnight.

&&

.MARINE...
High pressure far northeast of the state will maintain moderate
to fresh trade winds across the coastal waters through tomorrow.
A Small Craft Advisory is in effect for typical windier waters
around Maui County and the Big Island through tonight and could be
extended if trade wind speeds remain elevated. Trade winds could
decrease towards the end of the week as the ridge moves closer to
the state.

South facing shore surf heights will continue to see a steady
increase to solid High Surf Advisory (HSA) levels through tonight.
A HSA is currently in effect for all south facing shores through
Wednesday night. Surf heights may reach low-end warning level
overnight if the swell comes in higher than guidance. Surf
heights are expected to decline Thursday into the weekend.

The current small northwest swell will slowly decline today and
tonight with mainly background energy by tomorrow. A small,
medium period north swell may fill in on Friday with a slight bump
to surf heights along north facing shores. Surf along east facing
shores will remain smaller than average due to the lack of strong
trade winds. The one exception will be for areas exposed to the
south swell.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Thursday for south facing
shores of all islands.

Small Craft Advisory until 6 AM HST Wednesday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

&&

DISCUSSION...Wroe
AVIATION...M Ballard
MARINE...Shigesato