Drought in Hawaii, July 1 to 31, 2022

Area Forecast Discussion
National Weather Service Honolulu HI
820 PM HST Thu Jun 30 2022

.SYNOPSIS...
High pressure north of the state will keep breezy to locally windy
conditions in place through the 4th of July Holiday weekend.
Fairly typical trade wind weather will prevail through Saturday,
with showers favoring windward and mauka areas, with the eastern
islands seeing a few more showers than the western end of the
state. An upper level trough will pass over the state Saturday
night through Sunday night, bringing an uptick in showers to
windward and mauka areas, and sending a few showers into leeward
communities. A more typical trade wind weather pattern is then
expected from Independence Day through next Friday, with a
gradual easing of the trades during the middle to latter part of
next week.

&&

.DISCUSSION...
Currently at the surface, a 1030 mb high is centered around 1000
miles north of Honolulu, and is driving breezy to locally windy
trades across the island chain this evening. Infrared satellite
imagery shows some low clouds moving into windward slopes and
coasts, with some high clouds streaming over the islands as well.
Partly cloudy conditions prevail in most areas, with a bit more
cloud cover in some windward and mauka locales. Radar imagery
shows scattered showers moving into windward areas, with the
greatest coverage over the eastern end of the state. Meanwhile,
most leeward areas remain rain free. Main short term focus
revolves around trade wind trends and rain chances.

High pressure north of the islands will keep breezy to locally
windy conditions in place through Tuesday. Winds will be close to
advisory levels at times over the typically windy areas of Maui
County and the Big Island through the 4th of July Holiday weekend,
and an advisory may eventually be needed. The trades should ease
into the moderate to locally breezy range Wednesday through the
end of the work week as the high weakens.

As for the remaining weather details, fairly typical trade wind
weather will prevail over Maui County and the Big Island during
the next couple days, while drier trade wind conditions hold in
place over Kauai and Oahu. A trough aloft along with some deeper
moisture will move into the islands Saturday night then gradually
dampen out as it lifts northwestward across the state Sunday and
Sunday night. This should increase trade wind showers statewide,
and although the brunt of the shower activity should continue to
focus over windward and mauka areas, a few more showers should
reach leeward communities as well. Additionally, conditions may
destabilize enough to allow for a thunderstorm or two Sunday
afternoon on the Big Island. Weak troughing aloft is forecast to
linger over the islands from Independence Day through late next
week, and this will likely keep a fairly typical summertime trade
wind regime in place.

A Wind Advisory remains in place for the Haleakala summit through
6 AM Friday. This will likely need to be extended through 6 AM
Saturday with the morning forecast package, as 700 mb winds will
change little between now and then.

Winds may pick up close to advisory levels on the Big Island
summits during the next couple days as well, so we will continue
to monitor this for the need for an advisory.

&&

.AVIATION...
Trade winds will be moderate to breezy, and locally strong, as
robust high pressure remains far north of the area. Showers and
any accompanying MVFR conditions in lower ceilings and
visibilities will mainly affect windward and mauka sections across
the state, with afternoon and evening cloud buildups over leeward
Big Island as well. VFR, however, will predominate in most areas
most of the time.

AIRMET Tango remains in effect for moderate low-level turbulence
downwind of the higher terrain of all islands.

&&

.MARINE...
A large, strong area of surface high pressure approximately 1,000
miles north of the islands is producing a very tight pressure
pressure gradient back toward the state. This is resulting in
sustained 20 to 25 knot trade winds across the coastal and
offshore waters, locally to 30 knots through the more eastern
island bays, channels and south of Big Island. These primarily
fresh to locally strong trades will persist through the weekend
with little to no weakening. A Small Craft Advisory (SCA) for
winds across most zones (except the leeward Maui and windward Big
Island waters) is in effect through Sunday afternoon. These winds
will create rough sea conditions as multiple days of fresh trade
flow over the local waters will result in an elevated east wind
wave chop. While many zones will remain under SCA threshold 10
foot seas, seas within the Alenuihaha Channel and south of Big
Island may approach and hit these values the next couple of days.

Surf will be very low along all shores through next week. The
current diminishing south swell continues to fade through Friday.
Only background south or southeast swell is expected into next
week. As mentioned above, trade wind wave and underlying short
period swell will hold rough and choppy surf along many eastern
facing exposures. Otherwise, no significant swells from any
direction are expected the next several days.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 6 AM HST Friday for Haleakala Summit.

Small Craft Advisory until 6 PM HST Sunday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters-Maalaea Bay-Pailolo Channel-Alenuihaha
Channel-Big Island Leeward Waters-Big Island Southeast Waters.

&&

DISCUSSION...Jelsema
AVIATION...Kinel
MARINE...Blood