High Surf in Hawaii, June 27 to 29, 2022

Area Forecast Discussion
National Weather Service Honolulu HI
336 AM HST Mon Jun 27 2022

.SYNOPSIS...
A high pressure system far north of the Hawaiian Islands will
build into the region today, increasing trade wind speeds into
the moderate to locally breezy range through Friday. Fairly
typical cloud and shower trends will return with passing showers
over the windward and mountain areas of each island, favoring the
overnight to early morning hours. An upper level disturbance
passing over the islands next weekend may briefly increase cloud
and shower trends.

&&

.DISCUSSION...
Satellite imagery this morning shows more stable cumulus and
stratocumulus clouds moving into the islands on the trade wind
flow. These clouds will bring brief passing showers to windward
and mountain areas through the early morning hours with decreasing
rainfall trends in the late morning to afternoon. Local radar
imagery shows scattered to numerous showers brewing across the
state. Scattered high level cirrus clouds continue to drift over
the state courtesy of the subtropical jet stream.

The high pressure system far north of the islands will build into
the region today, increasing trade wind speeds to the moderate to
locally breezy range by this afternoon. Upper air balloon
soundings show trade wind inversion heights in the 5,500 foot to
8,000 foot range for Lihue and Hilo respectively. Model cross
sections continue to show trade wind temperature inversion heights
will range between the 6,000 to 8,000 feet, which means cloud
tops will be high enough for continued passing showers over
windward and mountain areas of each island through Friday. Clouds
and showers will continue to favor overnight to early morning
hours.

An upper level low drifts into the area by this weekend. This
upper low will anchor a lower level 700 mb trough under the low
center as the system drifts from southeast to northwest across the
islands. The passage of this low may briefly increase long range
cloud and shower coverage trends from Saturday through Sunday.
Stay tuned.

&&

.AVIATION...
Light to moderate trades will persist through the morning hours,
then increase into the moderate to breezy category this afternoon.
Although VFR conditions will prevail for most areas, expect brief
periods of MVFR CIGS/VSBYS in and around showers that develop and
move through.

There are currently no AIRMETs in effect. However, AIRMET Tango
for low-level mechanical turbulence over and downwind of
mountains is possible this afternoon as the trades strengthen.

&&

.MARINE...
A surface high well north of Kauai will build far northeast of
the state today through Tuesday, leading to an increase in trade
winds to fresh to locally strong speeds. Therefore, a Small Craft
Advisory has been issued for the typically windy waters around
the Big Island and Maui County through Tuesday afternoon, but will
likely be extended through next weekend.

The first pulse of south swell that came in larger than expected
has now begun to decrease. A High Surf Advisory remains in effect
through this afternoon. Although a slight decline in surf is possible
late today through tonight, the next pulse of south swell due on
Tuesday will keep south shore surf up around advisory level through
Wednesday. This swell will gradually decline Thursday and Friday.

Surf along exposed north and east facing shores could see a bump
in small, short period swell through today. Surf along north
shores will drop Tuesday, while strengthening trade winds will
boost rough east shore surf to around seasonal average into next
weekend.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 PM HST this evening for Niihau-Kauai
Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai
South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai Leeward
South-Lanai Leeward-Lanai South-Maui Central Valley South-South
Maui/Upcountry-South Haleakala-Big Island South-Big Island
Southeast.

Small Craft Advisory from 6 AM this morning to 6 PM HST Tuesday
for Maalaea Bay-Pailolo Channel-Alenuihaha Channel-Big Island
Leeward Waters-Big Island Southeast Waters.

&&

DISCUSSION...Bohlin
AVIATION...Gibbs
MARINE...TS