433
FXHW60 PHFO 210204
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
404 PM HST Fri Feb 20 2026

.SYNOPSIS...
Trades will quickly dissipate tonight as an upper level trough
swings through the state tonight into Saturday. Expect increasing
chances for heavy rain and isolated thunderstorms through Saturday
especially along windward areas. The threat for heavy rain and
thunderstorms should diminish by Saturday evening as the main
trough axis lifts north of the state. Strengthening trades around
Tuesday of next week will bring some showery weather, followed by
more stable conditions by mid to late week.


&&

.DISCUSSION...
Issued at 404 PM HST Fri Feb 20 2026

Water vapor imagery is showing a short-wave trough approaching the
state this afternoon from the west, which should help produce
showers and isolated thunderstorms over the western half of the
state tonight. A Flood Watch remains in effect for Kauai and
Niihau through tonight, and the latest HREF model agrees with the
heaviest rainfall rates occurring during the evening and
overnight hours. Unstable and showery conditions should persist on
Saturday, but the greatest flooding risk should be tonight as the
upper trough swings through Kauai.

Over on Oahu, we are seeing showers training along the Ko`olau
Range this afternoon. Low level winds have weakened and veered
toward the east-southeast and we are seeing a plume of moisture
drifting towards Oahu from Molokai. Training showers will likely
continue along the Ko`olau range through this evening, which will
lead to rises along the streams and some minor flooding possible
along low lying areas. For the most part, rainfall rates have been
holding in the 0.5 to 1 inch per hour rate, but rainfall rates
could increase this evening as instability increases from the
approaching upper level trough. The upper level trough should
bring an increase of showers and isolated thunderstorms late
tonight into Saturday for Oahu.

For rest of the state, showers should be on the increase Saturday,
with windward areas likely seeing the greatest shower coverage.
Isolated thunderstorms will be possible, but if any thunderstorms
do form, they will likely be brief and isolated. Some localized
flooding impacts will be possible, especially windward areas. The
summits of the Big Island could also see some snow showers
Saturday afternoon, which may prompt a Winter Weather Advisory.

By Sunday, the main moisture axis should lift off to our north and
while conditions aloft will still be unstable, we will lack the
moisture on Sunday. So overall Sunday should start off fairly
nice, with sea breezes developing during the day. Sea breezes
should allow for some afternoon clouds and showers over interior
and mountain areas. Any showers that do develop could be heavier
than usual due to the instability aloft.

Beyond the weekend, model guidance suggests the main band of
moisture staying north of the state through Monday. As high
pressure builds north of the state Monday night into Tuesday, this
band of moisture will ride in with the returning trade winds
Tuesday into Tuesday night. By the second half of next week, mid-
level ridging is expected to build overhead, supporting a more
stable pattern with moderate to breezy trade winds.


&&

.AVIATION...
Issued at 404 PM HST Fri Feb 20 2026

Trade winds will weaken this evening and Saturday as the pressure
gradient weakens and an upper level trough moves over the islands
from the west. Showers are expected to increase in coverage from
west to east tonight through Saturday. We expect localized MVFR
and isolated IFR in the strongest showers.

AIRMET Sierra is in effect for mountain obscuration above 2 kft
for north through southeast Oahu, east Maui, and north and east
Big Island due to showers.

AIRMET Tango remains in effect for tempo moderate turbulence
below 8000 feet over leeward sides of the islands as a result of
continued breezy low level winds. Conditions are expected to
improve as winds weaken tonight.


&&

.MARINE...
Issued at 404 PM HST Fri Feb 20 2026

Strong trades will persist today, then begin to ease over the
weekend as a gale nearby to the NW lifts NNE and away from the
region. Winds may become light enough for a localized land and sea
breeze regime to become established over the weekend. Seas will
respond by gradually lowering, likely falling below the 10 ft
Small Craft Advisory level by early Saturday. In addition to the
winds and seas, expect a wet pattern with isolated thunderstorms
to develop by tonight as an upper disturbance moves over the
state.

Nearshore PacIOOS buoys indicate NE energy through the entire
spectrum, encompassing wind wave action and fresh trade wind swell
propagating through area waters. Swell still hovers near the
advisory threshold at forecast issuance time this afternoon as it
lags the decrease in winds by at least several hours. The High
Surf Advisory has therefore been extended through tonight. A
downward trend is then expected over the weekend as winds diminish
both locally and upstream.

Impactful NNE swell anticipated early next week. Surf along
exposed N and E shores will quickly build through the day Monday
as a long-period NNE (020) swell from a broad storm-force low
evolves off the Pacific NW coast coast this weekend. A large area
of northerly gales between this system and a 1048 mb blocking high
centered over the Aleutians will expand southward Friday through
the weekend, with the head of the fetch reaching less than 1,000
nautical miles from the state. Surf will reach High Surf Warning
thresholds for exposed N and E shores by late Monday through
Tuesday. Although a gradual downward trend is anticipated by
midweek, additional pulses from this same system will keep surf
above the advisory threshold for E shores through much of next
week. This swell direction will bring surf into some typically
protected areas such as Kua Bay, West Maui, and exposed shores of
Lanai.

Next week`s NNE (020) swell will also produce significant erosion
along some coasts and accretion at other locations as sand shifts
opposite the typical swell direction, particularly along N facing
shores. Overwash of roads and vulnerable sections of coastline is
likely beginning Monday night during high tide cycles. Mariners
can also anticipate harbor surges in Kahului and Hilo.

Surf along exposed W shores will rise early next week as a long-
period NW swell arrives from a broad storm-force low currently
located over the far northwest Pacific near the Kurils.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for Kauai East-Kauai Mountains-
Kauai North-Kauai South-Kauai Southwest-Niihau.

High Surf Advisory until 6 AM HST Saturday for Big Island East-
Big Island North-Big Island Southeast-East Honolulu-Kauai East-
Kauai South-Kipahulu-Koolau Windward-Maui Windward West-Molokai
Southeast-Molokai Windward-Olomana-Windward Haleakala.

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


&&

$$

DISCUSSION...Kino
AVIATION...Parker
MARINE...JVC