Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 09/26/2026 01:22:00 AM UTC

                        
195
FXHW60 PHFO 251522
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
522 AM HST Fri Sep 25 2026

.SYNOPSIS...
Hurricane Nolo continues to slowly move to the north towards the
Big Island, and is expected to make a turn to the west tonight.
Moisture on the north side of Nolo will interact with the terrain
of the Big Island and Maui, and could lead to significant flash
flooding, particularly on the windward and southeast portions of
the Big Island. Localized strong and gust winds are possible
statewide, with the highest winds expected on the Big Island due
to the proximity to Nolo.

&&

.DISCUSSION...
The main change this morning to the forecast was to lower the
additional rainfall that could fall over Maui County and the Big
Island, and to modify the winds in keeping with the latest
forecast track and intensity of Hurricane Nolo.

Hurricane Nola continues to moving slowly northward towards the
Big Island early this morning. An upper level trough west of the
islands is helping to steer Nolo. As the trough moves to the west
tonight and Saturday, Nolo should begin to make its turn westward.
Then a building ridge north of the state will help Nolo to
continue to move to the west. The current forecast track is
similar to yesterday evenings forecast, however with a delay in
the onset of rain on the Big Island and Maui, and in keeping with
other model guidance, have lowered the additional rainfall that is
expected for those areas. While we have lowered some of the
threat, the possibility of flooding continues. And with many areas
of the southeast portion of the Big Island susceptible due the
recent rains, any additional rainfall could cause significant
issues. As such, the Flood Watch continues for Maui and the Big
Island. Additionally, some modifications to the winds, primarily
to lower them over the next couple of days, have been made, also
keeping with the latest model guidance.

With regards to the winds over Kauai County and Oahu, have opted
to hold off on any wind headlines this morning. The west turn
timing plays a big factor in many parts of the forecast, including
the timing of winds for Kauai County and Oahu. Oahu remains at a
slightly higher chance for meeting High Wind Warning criteria, but
still a good shot for Kauai reaching advisory levels.

Satellite derived precipitable water (PW) shows the deeper
moisture has moved over the Big Island, but radar shows that the
shower activity remains to the south. Still expecting shower
activity to increase over the Big Island today as Nolo moves
north, pushing that moisture area into the Big Island. The
additional rainfall totals were trended down with the morning
package, however the possibility of localized significant totals
remains. Strengthening northeast winds are expected to drive
moderate to heavy showers over windward portions of the Big Island
and Maui as moisture deepens and spreads northward over the
region.

A High Wind Watch for Oahu Saturday and Saturday night
remains a possibility. The Hurricane Watch and Tropical Storm
Warning remain in effect for the Big Island and the Tropical Storm
Watch continues for Maui County.

By the middle of next week, troughing will draw Nolo sharply north
or northeastward west of Kauai. The end of next week will then feature
light south to southeast flow as Nolo lifts north of the area and
gradient over the state weakens substantially.


&&

.AVIATION...
Gusty trade winds continue across most of the islands today with
gusts peaking between 25 to 35 knots while gusts up to 40 knots
are possible at the windiest sites. Winds are expected to remain
gusty through the end of the TAF period. Confidence has decreased
slightly in showers reaching the more northern islands given
Nolo`s more southerly track. That being said, trade showers are
likely to continue across the northern islands today while heavier
rain remains concentrated from Molokai down through the Big
Island. The highest potential for moderate to heavy rain remains
across the Big Island with reductions in ceilings and visibilities
likely as shower activity becomes more frequent. This may result
in periods of IFR to LIFR conditions in heavier showers on the Big
Island today into tomorrow. Thunderstorm chances remain low for
the Big Island. Temporary MVFR conditions are possible across the
rest of the islands as showers develop.

AIRMET Sierra is in effect for mountain obscuration for windward
areas of Maui, Molokai, and the entire Big Island.

AIRMET Tango remains in effect for moderate turbulence downwind of
island terrain due to breezy trade winds. Expect this to continue
through the forecast period.

TC SIGMET series Oscar covers Hurricane Nolo.


&&

.MARINE...
At 3 AM HST, the center of Hurricane Nolo was located approximately
180 nautical miles south of South Point, Big Island. Nolo is
expected to strengthen the next couple of days as it tracks slowly
north through the day and then turns west this weekend, passing
south of the Hawaiian Islands. Nolo`s maritime impacts will
include tropical storm/gale force winds, large waves, and high
rain probabilities across both the nearshore and offshore waters
through the weekend. A Tropical Storm Warning and a Hurricane
Watch remains in effect for the nearshore waters surrounding Big
Island, including the Alenuihaha Channel, while a Tropical Storm
Watch remains in effect for the waters of Maui County including
the Kaiwi Channel. A Small Craft Advisory remains in effect for
the remainder of the near coastal waters and channels surrounding
Kauai and Oahu.

Hurricane Nolo will produce a moderate size, long period south
swell that will result in surf exceeding High Surf Advisory
thresholds along exposed southern shores, initially for Big
Island today and tomorrow, and then possibly expanding westward
across the state early next week. Strong trades will likely result
in advisory level surf for the eastern island east and southeast-
facing shores through tomorrow, potentially expanding to remaining
islands this weekend as stronger winds expand westward. A High
Surf Advisory will remain in effect for the east and southeast-
facing shores of Big Island, Maui and Molokai. For the western
islands, a small southwest swell will build in from today and hold
into the weekend.

A small, long period northwest swell will fill in this weekend and
keep surf slightly elevated along north and west-facing shores into
early next week. Finally, dangerously large wind waves will produce
a rough and choppy sea state for much of the area the next several
days, with the largest waves (which could reach upwards to 20 feet
in some locations) expected around Maui County and Big Island.


&&

.FIRE WEATHER...
Issued at 458 AM HST Fri Sep 25 2026

Winds will steadily as Hurricane Nolo moves closer. Very strong
winds are possible on the Big Island, though heavy rainfall will
likely mitigate fire danger over most areas. From Kauai to Maui
County, rainfall over the last month has led to some improvement
in fuels, but the gusty trade winds will produce moderate fire
weather conditions over drier leeward areas through the weekend.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Saturday afternoon for Big Island East-Big
Island Interior-Big Island North-Big Island South-Big Island
Southeast-Big Island Summits-Haleakala Summit-Kahoolawe-Kipahulu-
Kohala-Kona-Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward-
Maui Central Valley North-Maui Central Valley South-Maui Leeward
West-Maui Windward West-Molokai Leeward South-Molokai North-
Molokai Southeast-Molokai West-Molokai Windward-South Haleakala-
South Maui/Upcountry-Windward Haleakala.

Tropical Storm Watch for Haleakala Summit-Kahoolawe-Kipahulu-
Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward-Maui
Central Valley North-Maui Central Valley South-Maui Leeward West-
Maui Windward West-Molokai Leeward South-Molokai North-Molokai
Southeast-Molokai West-Molokai Windward-South Haleakala-South
Maui/Upcountry-Windward Haleakala.

High Surf Advisory until 6 PM HST Saturday for Big Island East-
Big Island North-Big Island Southeast-Kipahulu-Maui Windward
West-Molokai Southeast-Molokai Windward-South Haleakala-Windward
Haleakala.

Hurricane Watch for Big Island East-Big Island Interior-Big
Island North-Big Island South-Big Island Southeast-Big Island
Summits-Kohala-Kona.

Tropical Storm Warning for Big Island East-Big Island Interior-
Big Island North-Big Island South-Big Island Southeast-Big
Island Summits-Kohala-Kona.

Tropical Storm Watch for Kaiwi Channel-Maalaea Bay-Maui County
Leeward Waters-Maui County Windward Waters-Pailolo Channel.

Hurricane Watch for Alenuihaha Channel-Big Island Leeward Waters-
Big Island Southeast Waters-Big Island Windward Waters.

Tropical Storm Warning for Alenuihaha Channel-Big Island Leeward
Waters-Big Island Southeast Waters-Big Island Windward Waters.

Small Craft Advisory until 6 PM HST Saturday for Kauai Channel-
Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward
Waters-Oahu Leeward Waters-Oahu Windward Waters.


&&

$$

DISCUSSION...M Ballard
AVIATION...Kennedy
MARINE...Blood
FIRE WEATHER...M Ballard