552
FXHW60 PHFO 140859
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
1059 PM HST Thu Aug 13 2026

.SYNOPSIS...
Increased trade winds, combined with relatively dry conditions,
will elevate the fire weather threat through Friday. Meanwhile,
occasional showers will favor windward and mauka areas through
Friday. For the weekend, we are continuing to monitor Tropical
Storm Lala as it moves west-northwest towards the main Hawaiian
Islands. A Hurricane Warning is in effect for Big Island and a
Tropical Storm Watch is in effect for Maui County.

&&

.SHORT TERM UPDATE...
Forecast remains on track for tonight into Friday, with a scattered
showers expected at times in windward and mauka areas. Trade winds
will increase tonight, becoming locally strong Friday. Near critical
fire weather conditions are still expected on Friday before humidity
increases from Tropical Cyclone Lala Friday night. For the weekend,
the weather will be most impacted by Tropical Cyclone Lala. In
addition to tropical headlines a Flood Watch is in effect for the
Big Island and Maui. Rainfall totals for the Big Island and parts
of Maui of 8 to 12 inches are expected, with isolated areas on
the windward Big Island possibly receiving more than 20 inches.
Rainfall totals up to 8 inches possible across the remainder of
the island chain.

&&

.PREV DISCUSSION...
Issued at 510 PM HST Thu Aug 13 2026
Late this afternoon, satellite and radar imagery show a few areas
of low clouds and showers embedded within the trade winds moving
into windward and mauka areas. However, rainfall has been light,
with only brief light showers passing through. Mostly dry
conditions are expected to continue through tonight and much of
Friday as well, with windward and mauka areas experiencing
scattered showers at times. Trade winds will gradually trend up,
becoming breezy tonight and locally strong on Friday.

The main forecast concern for the next few days will be potential
impacts from what is now Tropical Storm Lala. As of 5 PM HST,
Tropical Storm Lala was located near 16.2N 147.5W and moving WNW
around 10 knots (11 mph). Based on the latest forecast from the
National Hurricane Center (NHC), Lala is expected to move near the
southern end of the Big Island Saturday morning, then continue
moving to the WNW, with the center of circulation remaining south
of the smaller islands. Impacts from Lala are expected to begin
for the eastern end of the state Friday night, and continue
through the weekend. Please stay up to date on the latest
forecasts, and prepare for the potential impacts described below.

FIRE WEATHER...Fire weather concerns will increase on Friday
ahead of any potential tropical cyclone`s arrival. Winds will
begin to strengthen while a dry and stable air mass with low
relative humidity moves overhead. This combination of lower
relative humidity and increasing wind speeds will approach
critical fire weather criteria, but the forecast currently stays
just below. However, strong winds can lead to extreme fire
behavior even if RH values are not quite low enough to officially
make criteria.

STRONG AND GUSTY WINDS...Winds will strengthen further on
Saturday, though the timing, direction, and magnitude of the
strongest winds remain highly dependent on the track and intensity
of the system. With the past few cycles, the track forecast for
Lala have nudged a bit farther south. However, even if the center
of the system remains south of the coast, winds can still produce
damage. For now, confidence is highest in wind impacts for the
Big Island and surrounding waters. Therefore, a Hurricane Warning
has been issued for the Big Island and its surrounding waters, and
a Tropical Storm Watch has been issued for Maui County.

HEAVY RAINFALL...This system will bring periods of heavy
rainfall. Orographic enhancement will result in locally higher
rainfall totals where moist tropical flow interacts with island
terrain. If heavier rainfall persists over the same locations,
flash flooding and rapidly rising streams are possible. Again, the
location of heaviest rain and any bands that would move through
the islands will be highly dependent on the system`s track, which
currently favors the highest rainfall totals for the Big Island
and Maui County (though the remaining islands could experience
heavy rain bands as well). The current forecast has 8 to 12
inches of rain for the Big Island and parts of Maui. Isolated
areas on the windward Big Island could potentially receive more
than 20 inches. All islands will see an elevated risk of heavy
rain and flash flooding. As far as timing, heavy rainfall is
currently forecast to impact the Big Island as early as late
Friday night, spread to Maui Saturday, and Lanai, Molokai, Oahu,
and Kauai Saturday night into Sunday. A Flood Watch has been
issued for the Big Island and Maui.


LARGE AND ROUGH SURF...Lala is expected to generate a large
easterly swell as it moves northwestward. Surf may build along
east-facing shores from east to west as the system approaches,
with warning level surf of 15 feet or larger possible into the
weekend.

In anticipation of critical new updates with each of the next few
advisory packages issued by the National Hurricane Center (NHC),
the NWS Honolulu will continue delaying the issuance of our
typical forecast package products (AFD, SFT, PFM, ZFP, SPF, CWF,
etc.) until after the release of NHC`s suite of products, to
incorporate the latest and most up-to-date information on Tropical
Storm Lala.

&&

.AVIATION...
Breezy trade winds will strengthen tonight and become locally
strong by Friday. Scattered showers will focus over mostly
windward and mountain areas, especially during the early morning
hours. Tropical Storm Lala will continue to approach the Big
Island from the east southeast on Friday and bring deteriorating
weather conditions, such as low visibility/lowered ceilings, heavy
rain, isolated thunderstorms, as well as very strong winds for
Friday evening through this weekend for much of the state.

AIRMET Tango for moderate turbulence remains in effect
immediately south and west of mountains due to strengthening low-
level winds and will likely continue for the next couple of days.
As wind speeds strengthen overnight and Friday an AIRMET for
strong winds greater than 30 kt may also needed to be added as
Tropical Storm Lala approaches the island chain from the
east southeast.


&&

.MARINE...

Breezy trades continue strengthen as governing high pressure sags
southward toward the islands and Tropical Storm Lala approaches
from the east. The Small Craft Advisory remains in effect and is
still scheduled to expand in coverage tonight as winds undergo a
modest increase in strength.

NE wind associated with Tropical Storm Lala, presently about 500nm
SE of Hilo, will undergo considerable strengthening Friday
through Saturday with strong winds potentially expanding to the
remainder of the state late Saturday into Sunday. A Hurricane
Warning is now in effect for the Big Island surrounding waters and
a Tropical Storm Warning has been issued for Maui County and
surrounding waters. Dangerous conditions including torrential
rainfall, a few thunderstorms, and high surf should be expected.
Lala will track WNW through the weekend, clearing the western
islands by Monday.

The High Surf Advisory remains in effect for south shores as long
period south swell peaks today and remains elevated through tonight.
Surf along south and west facing shores associated with this swell
then begins to diminish as the period shortens. Another long period
south swell arrives late Sunday into Monday bringing another boost to
surf.

For E shores, surf initially trends slowly upward in association
with gradually strengthening trades. Additional swells generated
by TC Lala will arrive on Friday followed by the main energy
arriving with the system itself this weekend. Surf along E facing
shores is expected to exceed the High Surf Warning threshold
during this time. Based on the latest forecast track and intensity
from the National Hurricane Center, dangerous surf will develop
around Maui and the Big Island on Saturday and around Oahu and
Kauai Saturday night into Sunday.



&&

.FIRE WEATHER...
Issued at 510 PM HST Thu Aug 13 2026
Moderate to breezy trade winds and relatively dry air will lower
afternoon humidities through Friday, raising fire weather
concerns. At this time, criteria for a Fire Weather Watch are not
forecast, but it`s close. Temperature inversion heights will range
between 5,000 to 7,000 feet through Friday. Increasing humidity
and rainfall with Lala will remove fire weather concerns from
Saturday into at least early next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Friday for Big Island South-
Big Island Southeast-East Honolulu-Ewa Plain-Honolulu Metro-
Kahoolawe-Kauai South-Kauai Southwest-Kona-Lanai Leeward-Lanai
South-Maui Central Valley South-Maui Leeward West-Molokai
Leeward South-Molokai West-Niihau-South Haleakala-South
Maui/Upcountry-Waianae Coast.

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.

Flood Watch from Friday evening through late Saturday night for
Big Island East-Big Island Interior-Big Island North-Big Island
South-Big Island Southeast-Big Island Summits-Haleakala Summit-
Kipahulu-Kohala-Kona-Maui Central Valley North-Maui Central
Valley South-Maui Leeward West-Maui Windward West-South
Haleakala-South Maui/Upcountry-Windward Haleakala.

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

Small Craft Advisory until 6 AM HST Saturday for Kaiwi Channel-
Maalaea Bay-Maui County Windward Waters-Oahu Leeward Waters-
Pailolo Channel.

Small Craft Advisory until 6 PM HST Friday for Alenuihaha
Channel-Big Island Leeward Waters-Big Island Southeast Waters-
Big Island Windward Waters.


&&

$$

UPDATE...CO
DISCUSSION...Parker
AVIATION...Thomas
MARINE...Quesada