Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 05/14/2026 11:52:00 PM UTC

                        
066
FXHW60 PHFO 141352
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
352 AM HST Thu May 14 2026

.SYNOPSIS...
Breezy trade winds will persist through today, with showers
favoring windward and mauka areas. An upper level disturbance will
briefly move over the state on Friday and will bring the threat
of heavy rain and isolated thunderstorms over select areas. While
widespread heavy rain is not expected, pockets of heavy rain with
some flooding impacts will be possible on Friday. Wetter than
normal conditions will likely persist through the weekend
especially over windward and mauka areas, where scattered showers
are expected.


&&

.DISCUSSION...
Broad high pressure far north of the state will maintain breezy
trade winds across the region through today, delivering clouds
and scattered showers to windward and mauka areas, particularly
during the overnight to early morning hours.

Starting tonight, the weather pattern will begin to change as a
cold upper level low drops southward towards the state. Latest
global guidance are in good agreement with the upper level low
centered over Kauai by Friday with 500 mb temps as cold as -14C.
The strength of the upper level low should induce a surface
trough, which should help act as a trigger for heavy showers and
isolated thunderstorms on Friday. With the center of the upper low
expected to be over Kauai, the best atmospheric forcing will be
over Oahu and parts of Maui County where guidance is showing over
1000 J/kg of CAPE by Friday afternoon. While widespread heavy
rain is not expected, we should see areas of heavy rain and with
light winds in the lower levels of the atmosphere, any heavy rain
that develops will be slow moving. With surface winds generally
out of the east to southeast, combine that with a cold upper level
low centered west of Oahu, generally is a favorable pattern for
heavy rain to potentially anchor along the Koolau Mountain Range.
While the threat for heavy rain will exist across the state on
Friday, the highest confidence is currently over Oahu and portions
of Maui County. A Flood Watch may be eventually needed for
portions of the state and we will continue to watch how the upper
level low evolves over the next 24 hours.

Over the weekend, the upper level low will begin to drift further
away from the state, which should decrease the threat of
thunderstorms. While the instability decreases over the weekend,
low level moisture will increase from the southeast with
precipitable water values approaching 2 inches by late Saturday
over windward Big Island. Periods of heavy rain is expected over
windward and southeast Big Island this weekend with some enhanced
showers possible elsewhere across the state.


&&

.AVIATION...

Breezy trades expected for next few days. Low cigs and SHRA
expected along windward and mauka locations. MVFR conds possible
but VFR should prevail.

AIRMET Tango is in effect for turb, lee of terrain due to the
breezy trades.


&&

.MARINE...
High pressure established north of the islands maintains locally
strong trades until an upper disturbance causes winds to weaken
by this weekend. Our current fresh to locally strong trades should
hold through the day today then gradually weaken and veer towards
the east-southeast tonight into Friday. Moderate to fresh east to
east-southeast winds are expected Friday into the weekend. The
SCA remains in effect for the windier zones of Maui County and the
Big Island through this afternoon. The upper level disturbance
will bring the threat of heavy rain and isolated thunderstorms on
Friday.

A new small to moderate, long period NW to NNW (320 degree to 330
degree) swell will steadily fill in this morning and will likely
peak later today and produce above average surf along north facing
shores. Latest readings on buoy 51001 did show swell heights of 4
feet 15 seconds, which is in line with guidance. This swell should
gradually fade tonight into the weekend.

Small, medium to long period S swell maintains small surf along S
shores. A series of gales initially passing south of New Zealand
a few days ago and now setting up E of New Zealand should send a
series of small south swells all of next week. Surf should rise to
near the summer average around Sunday and hold near the summer
average throughout next week. Meanwhile along east facing shores,
locally strong trades will maintain rough and choppy surf along E
facing shores. A slight decrease of wind swell is expected
Thursday into Friday as the trades weaken to moderate to locally
fresh speeds.

Tides peak around 2.5 ft MLLW this weekend. Combined with ongoing
trades and a modest boost in S swell, water levels will peak
around 3.0 ft late this weekend into early next week. Minor
overwash of low lying coastal areas will be possible during the
afternoon high tides at this time.


&&

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


&&

$$

DISCUSSION...Kino
AVIATION...Walsh
MARINE...Kino