Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 09/05/2026 04:20:00 PM UTC

                        
629
FXHW60 PHFO 050620
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
820 PM HST Fri Sep 4 2026

.SYNOPSIS...
Breezy trade winds continue through the weekend with clouds and
showers focused windward and mauka. Hurricane Lowell is forecast
to move close to Kauai County Monday night as a category 2 to 3
hurricane. Weather impacts such as high surf and heavy rain are
forecast to extend hundreds of miles from the center of Hurricane
Lowell, potentially impacting any of the islands.


&&

.DISCUSSION...
Radar and infrared satellite show partly cloudy skies and
isolated trade showers this evening. Breezy trade winds continue
through the weekend. Clouds and showers will gradually increase
through the weekend as trade winds push in a bit more upstream
moisture. Focus of the showers will be windward and mauka and
occur mostly during the overnight and early morning hours through
Sunday.

Our attention will then turn to Hurricane Lowell, now a category
5 on the Saffir-Simpson scale (140 mph maximum sustained winds),
and impacts to Hawaii. Lowell is about 600 miles south southwest
of Kauai this evening still tracking to the west. A gradual
decrease in the forward speed of Lowell remains in the forecast
for the next 12-18 hours, followed by a turn to the northwest
Saturday and north-northeast Sunday. Lowell is expected to make
its closest approach to the main Hawaiian Islands Monday night as
a category 2 to 3 hurricane, and any deviation eastward from its
forecast track could bring more severe wind impacts especially to
Kauai County. It is currently too early for tropical watches and
warnings tonight, but will be discussed and determined soon.

As far as expected impacts, there remains a risk for high surf,
strong winds, and heavy rainfall for all islands. A south swell
has already elevated surf across south facing shores and will
become extra large out of the southwest Sunday night/Monday as
Lowell approaches. High surf will have the greatest coverage
across the state as the swell moves from the storm, so confidence
is highest with the surf and surge impacts.

Winds will shift southward and deep tropical moisture will advect
across all islands late Sunday through Tuesday, producing warm and
humid weather conditions. Heavy rainfall is likely to impact most
islands at some point during Lowell`s passage. NBM guidance
initially brings heavy rain across south slopes of Maui and Big
Island as early as Sunday evening followed by the rest of Maui
County and Oahu Monday morning, and Kauai Monday afternoon. Initial
storm total rainfall estimates range from 2 to 8 inches statewide.
With a significant period of south to southeast winds forecast,
we expect locally higher amounts (around 10 inches) along south
and southeast slopes. Please continue to closely monitor the
weather forecast for early next week as the track and associated
impacts with Hurricane Lowell may change over time.

High pressure builds back over the islands from Tuesday afternoon
onward as a wet trade wind pattern with periods of passing showers
sets up across the state into the end of next week. A moist area
left from the remains of Karina is now modeled to move through
the area Wednesday afternoon through Wednesday night, possibly
providing an especially wet period.


&&

.AVIATION...
Breezy trade winds will gradually decrease in strength through
Sunday as the ridge north of the islands weakens. Hurricane Lowell
roughly 600 miles south of Kauai continues to journey westward.
Bands of unsettled clouds are developing in the trade winds just
northeast of the Hawaiian Islands. Expect increasing cloud and
shower trends bringing MVFR conditions over windward mountain
areas lasting into the early morning hours with the potential for
an AIRMET Sierra issuance for mountain obscurations later this
evening.

AIRMET Tango remains in effect for low level mod turb over and
south through west of all island mountains.


&&

.MARINE...
A surface high persists north of the Hawaiian Islands and will
slowly drift east through the weekend. Currently, Hurricane Lowell
is passing near 520 nm south to southwest of the islands as it
continues to track west. The interaction between the two has kept
trade winds fresh to locally strong across the all coastal waters
zones. A Small Craft Advisory (SCA) is in effect for all coastal
waters through tonight and has been trimmed back on Saturday for
only the windier waters and channels around Maui County and the
Big Island through Saturday afternoon. As Lowell begins its
expected turn northward this weekend, by early next week winds are
likely to veer to the southeast to south with the strongest winds
over the western end of the state.

Confidence has grown with the latest updates from the National
Hurricane Center for the potential for hurricane conditions in
the offshore waters west of 160W on Sunday through potentially
Tuesday. How close it gets to the state, is yet to be determined.
As for Hurricane Karina, it is expected to weaken and pass to the
north and northeast of the state.

Southerly swells from Hurricane Lowell will keep surf elevated
above High Surf Advisory (HSA) conditions through Saturday. A
large, medium- period east swell is filling in from Hurricane
Karina producing HSA level surf along east facing shores. The
HSA is in effect for all south and east facing shores of all
islands as well as the west facing shores of the Big Island
through Saturday afternoon and will likely be extended.

The swell from Lowell will gradually veer from south to southwest
early next week. While the forecast for swells and seas for next
week will highly depend on the eventual track and intensity of
Lowell, confidence is beginning to increase for the potential of
extra- large surf (exceeding warning levels) along south and
western exposures early next week. Coinciding also with monthly
high tides, this will create the potential for impacts to harbor
entrances, channels, as well as coastal properties and
infrastructure including roadways.


&&

.FIRE WEATHER...
Periods of passing showers will mainly impact windward and
mountain slopes through early Sunday. Considerably more showers
are likely over most areas from Sunday afternoon into early next
week. The temperatures inversion heights near Maui and the Big
Island will range from 6,000 to 7,000 feet elevation tonight and
Saturday.


&&

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

Small Craft Advisory until 6 AM HST Saturday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters-Maui County Leeward Waters-Big Island
Windward Waters.

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


&&

$$


DISCUSSION/FIRE WEATHER...Foster
AVIATION...Bohlin
MARINE...Shigesato