744
FXHW60 PHFO 070314
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
514 PM HST Sun Sep 6 2026

.SYNOPSIS...
Breezy easterly trade winds will continue to gradually veer to the
east-southeast over the next day or so as Hurricane Lowell
approaches the western islands from the south. Lowell is forecast
to pass west of Kauai`s coastal waters Monday night. A Tropical
Storm Warning and Hurricane Watch are in effect for Kauai, Niihau
and the surrounding coastal waters as a result. Impacts such as
high surf and heavy rain could impact all of the islands.


&&

.DISCUSSION...
Hurricane Lowell is about 500 miles south-southwest of Kauai this
afternoon and is moving northward. Lowell is expected to pass
west of the Kauai coastal waters late Monday through Monday night.
Tropical storm force winds are expected to reach Kauai and Niihau
at the the closet approach, and thus a Tropical Storm Warning is
in effect for Kauai County and the surrounding coastal waters. As
the track has nudged to the east, it has raised the possibility
of hurricane force winds reaching Kauai and Niihau, as a result a
Hurricane Watch has also been issued for these areas.

Additional impacts from Lowell are expected statewide, and a few
headlines are in effect as a result. The High Surf Advisory has
been upgraded to a High Surf Warning for the south swell generated
by Lowell for all islands, along with the west facing shores of
the Big Island. A High Surf Advisory remains in effect for the
east swell generated by former Tropical Storm Karina, which has
weakened to a post tropical low which is about 620 miles east
northeast of the Big Island this afternoon.

The Flood Watch for the state continues through Tuesday afternoon.
Rain being carried in on the easterly trade winds this morning
has started to shift out of a slightly southeast direction in
response to the winds beginning to veer, and the interaction with
the terrain on a few islands has led to some heavier rainfall.
Additionally some thunderstorms formed over the Big Island slopes
this afternoon bringing heavy rain there. As a result, some flood
advisories and warnings have been issued, and more are possible as
the event continues to unfold. With Kauai and Niihau being the
closest to Lowell, rainfall totals are expected to be highest
there, but due to the terrain influence on the Big Island,
isolated areas could receive significant rain over the next couple
of days. Stay alert for the issuance of any future flood
advisories or warnings across the state.

The threat of short-lived, fast-moving tornados/waterspouts will
be present mainly near Kauai and Niihau as Lowell makes its
closest approach to the islands. These would likely be embedded in
rainbands. The threat for tornadoes is lower near the remaining
islands, but not zero. The threat for tornadoes should decrease
quickly early Tuesday morning.

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 a more typical trade wind pattern with a
drier and more stable airmass.


&&

.AVIATION...
Hurricane Lowell continues its track northward, bringing an
abundance of tropical moisture along with it. Shower and cloud
coverage has already increased today and will continue to increase
through the overnight hours. MVFR conditions in low cloud
ceilings and showers are expected through Monday. Heavier showers
will produce IFR conditions. MVFR/IFR conditions for Kauai County
directly associated with Hurricane Lowell will begin on Monday,
and tropical storm force winds will likely occur Late Monday -
Monday night.

The wind regime will begin veering ESE - SE tonight and through
tomorrow. Surface winds will also strengthen overnight and
through Monday, especially over the western half of the state, as
Hurricane Lowell continues on its northward track.

AIRMET Sierra for mountain obscuration continues for windward
areas of Kauai Oahu Molokai Maui and the entire Big Island. This
AIRMET will likely be adjusted to cover other areas and islands
as shower coverage increases with time.

AIRMET Tango is currently in effect for moderate turbulence
between FL270 and FL360 due to an upper level disturbance.

Light icing is possible in a layer between 160 and FL250 due to
upper level clouds from the tropical disturbances moving over the
state.


&&

.MARINE...
Hurricane Lowell located southwest of the islands continues to
move north slowly this afternoon. As it approaches the island
chain wind speeds will begin to increase. A Tropical Storm Warning
and a Hurricane Watch is in effect for waters around Kauai County
through Tuesday afternoon. A Small Craft Advisory has been
expanded due to a combination of winds and seas through Monday
night. Winds are expected to increasingly veer to the southeast to
south as Lowell continues to approach and bring the strong winds
to the western end of the state.

Hurricane conditions are expected in the western offshore waters
tonight through Tuesday as the center of the storm is expected to
track just west of Niihau. Any slight deviation in the track to
the west or east in the next 24 hours will have significant
differences in impact for the coastal waters around Kauai County.
Post Tropical Storm Karina to the northeast of the islands will
continue to weaken and dissipate by Monday.

The High Surf Advisory (HSA) has been upgraded to a High Surf
Warning (HSW) for all south facing shores through Monday night.
Surf will continue to trend in the HSA range through tonight
before the south swell from Hurricane Lowell is expected to rise
rapidly Monday, and peak Monday night bringing warning level surf
to exposed shorelines. This swell may shift out of the southwest
late Monday night. Due to the track of Lowell, a sharp gradient in
swell is expected from west to east. Coinciding also with the peak
monthly afternoon high tides,this could bring the potential for
significant damage to coastal properties and infrastructure,
including roadways to portions of Kauai and possibly Oahu. Swell
energy is expected to drop off quickly on Tuesday.

A large, medium-period east swell from former Tropical Storm
Karina will also continue to produce HSA level surf along east
facing shores through Monday night. Surf along north facing shores
will remain flat except areas exposed to the storm swells. A
small medium period northwest swell is expected on Tuesday and
will fade through Thursday. By the end of the 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...
Fire weather risk will remain low through the forecast period due
to increasing moisture moving over the islands in association
with Hurricane Lowell. Thunderstorms will be possible through
tomorrow due to the unstable airmass moving overhead. Temperature
inversion heights are currently near 11,000 ft from Maui to the
Big Island, and are expected to remain elevated during the next
few days.

&&

.HYDROLOGY...
The potential for flooding exists through Tuesday afternoon, and
as a result, a Flood Watch is in effect for the entire state.
Between now and Tuesday afternoon, Hurricane Lowell is expected
to bring additional rain to the islands with 6 to 10 inches for
Kauai, with maximum totals of 14 inches possible. For the Big
Island, 4 to 8 inches of rain is expected with isolated totals of
12 inches, due to the terrain influence with the southeast flow.
Across the remaining islands, rainfall of 2 to 4 inches of rain is
expected, with Maui having isolated maximum totals of 8 inches
possible. This rainfall may produce significant flash flooding and
mudslides, especially across Kauai County and portions of the Big
Island.

&&


.HFO WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Tuesday afternoon for the entire state of
Hawaii.

High Surf Warning until 6 AM HST Tuesday for Big Island South-
Big Island Southeast-East Honolulu-Ewa Plain- Honolulu Metro-
Kahoolawe-Kauai East-Kauai South-Kauai Southwest- Kipahulu-
Kohala- Kona-Lanai Leeward-Lanai South-Maui Central Valley South-
Maui Leeward West-Molokai Leeward South-Molokai Southeast-Molokai
West-Niihau-South Haleakala-South Maui/Upcountry-Waianae Coast.

Hurricane Watch for Kauai East-Kauai Mountains-Kauai North-Kauai
South-Kauai Southwest-Niihau.

Tropical Storm Warning for Kauai East-Kauai Mountains-Kauai
North-Kauai South-Kauai Southwest-Niihau.

High Surf Advisory until 6 AM HST Tuesday for Big Island East-
Big Island North-Koolau Windward-Molokai Windward-Olomana-
Windward Haleakala.

Hurricane Watch for Kauai Leeward Waters-Kauai Northwest Waters-
Kauai Windward Waters.

Tropical Storm Warning for Kauai Channel-Kauai Leeward Waters-
Kauai Northwest Waters-Kauai Windward Waters.

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


&&

$$

DISCUSSION/FIRE WEATHER/HYDROLOGY...M Ballard
AVIATION...DT
MARINE...Shigesato