732
FXHW60 PHFO 051951
AFDHFO

Area Forecast Discussion...RESENT
National Weather Service Honolulu HI
951 AM HST Sat Sep 5 2026

.SYNOPSIS...

Breezy east-northeast trade winds will gradually veer to the east
and then east-southeast this weekend into the upcoming week as
Hurricane Lowell approaches from the southwest. Lowell is
forecast to pass west of Kauai`s coastal waters as a major
Hurricane (category 3). Impacts such as high surf and heavy rain
are forecast to extend hundreds of miles from the center,
potentially impacting any of the islands.

&&

.DISCUSSION...

Radar and satellite imagery this morning shows a fairly typical
summertime trade wind pattern with scattered showers over windward
and mountain areas. Increasing moisture upstream is also evident and
will contribute to increasing showers this evening into tomorrow
mostly for windward and mountain areas. Weather conditions then
deteriorate Sunday evening into the upcoming week.

Hurricane Lowell is currently sitting about 540 nautical miles
south-southwest of Kauai moving west at 6 kt as a category 4 (150
mph maximum sustained winds). Lowell is forecast to make a sharp
turn to the north and then north-northeast at some point later
today into tonight. It`s forward speed will increase once it
begins moving north and will make its closest approach to the main
Hawaiian Islands Monday night as a category 2 to 3 hurricane.
Lowell is forecast to pass west of Kauai`s coastal waters, and
will bring several hazards to the state. The hazards are expected
to be flooding, strong southerly winds, and high surf.

The greatest risk for flooding at this time appears to be Sunday
evening through Tuesday morning, and could potentially linger into
Wednesday, as deep tropical moisture associated with Lowell is
drawn up from the south. The environment will begin destabilizing
Sunday afternoon as GFS model CAPE values increase, along with
moisture depth. The winds will also veer to the east- southeast
and increase starting Sunday evening. The threat of heavy rainfall
and thunderstorms will be present anywhere in the state, and
flooding could occur as a result. Exact details on where the
heaviest of rain will fall remain uncertain, as any heavy showers
and thunderstorms that develop will likely be disorganized.
Therefore everyone in the state should be prepared for flooding.
The issuance of a flood watch is anticipated later this afternoon.

Winds will increase and veer out of the east-southeast by Sunday
night into Monday morning with Kauai County having the strongest
winds. Winds will also increase out of the southeast for the rest
of the islands to a lesser extent, and could be amplified by
island terrain.

For surf and other marine impacts, please see the marine section
of the discussion below.

Any deviation in track or intensity could also change how these
hazards effect the islands.

High pressure is forecast to build back in Thursday through
Saturday, bringing in drier and more stable conditions. Long range
models then indicate a tropical wave potentially moving over the
islands next Sunday into Monday, although confidence is very low
this far out.

&&

.AVIATION...
A stable, moderate to locally fresh trade wind flow will focus
scattered showers and produce areas of MVFR conditions over
windward slopes today, while VFR will prevail leeward. AIRMET
Sierra for mountain obscuration may be needed over some windward
areas. AIRMET Tango remains in effect for low-level mod turb over
and south through west of all island mountains.

Expect winds to hold at current strength and veer more easterly
on Sunday. The atmosphere will slowly destabilize through the
day, and deepening moisture along the far periphery of Hurricane
Lowell may overspread the state and lead to isolated heavy
showers and thunderstorms in the afternoon.

&&

.MARINE...

A surface high persists north of the Hawaiian Islands and will
slowly drift east through the weekend. Currently, Hurricane Lowell
is around 540 nm south-southwest of the islands as it continues
to track west. The trade winds are beginning to ease slightly as
Lowell gains a bit of distance from the island chain, and the
Small Craft Advisory (SCA) has been trimmed back to only the
windier waters and channels around Maui County and the Big Island
through this afternoon. Lowell is expected to turn northward on
Sunday, which will cause winds 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 Sunday night through Tuesday.
While confidence is increasing in the track forecast of the
cyclone, a deviation in track of 50 nm west or east from the
current predicted path will have significant differences in impact
for the coastal waters around Kauai County. As for Hurricane
Karina, it is expected to weaken and pass northeast of the
state.

Southerly swell generated by Hurricane Lowell will keep surf along
south facing shores at High Surf Advisory criteria today. As Lowell
begins to turn north on Sunday, its swell will gradually veer from
south to southwest and begin a rapid upward trend. Very large surf
exceeding warning criteria appears increasingly likely for south and
west facing shores on Monday. 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. Surf will then rapidly decrease
on Tuesday after the hurricane passes north of the island chain.
A pulse of northwesterly swell could then bring a bump to north
shore surf on Tuesday and fade through Thursday.

East facing shores will see continued advisory level surf from a
large, medium-period east swell generated by Hurricane Karina to the
east of the islands. This swell will gradually fade early next week as
Karina weakens into a tropical storm. Late next week, surf along east
facing shores could be bolstered by some medium-period swell generated
by Hurricane Marie in the East Pacific. Otherwise, expect choppy
conditions from easterly trade wind swell through the week.

&&

.FIRE WEATHER...

Passing showers will mainly impact windward and mountain slopes
through early Sunday. Showers then considerably increase Sunday
afternoon into next week. The temperatures inversion heights near
Maui and the Big Island will range from 6,000 to 7,000 feet
elevation today.

&&

.HYDROLOGY...

At this time, heavy rain looks like a possibility statewide
beginning Sunday evening through potentially Wednesday, depending
on how long the moisture lingers in the area. 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. The issuance of a flood watch is anticipated
later this afternoon for the whole state.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 PM HST Sunday 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 PM HST this evening for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.


&&

$$


DISCUSSION/FIRE WEATHER/HYDROLOGY...Tsamous
AVIATION...Wroe
MARINE...Quesada