Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 05/13/2026 11:10:00 AM UTC

                        
955
FXHW60 PHFO 130110
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
310 PM HST Tue May 12 2026

.SYNOPSIS...
Breezy trade winds will continue through most of the week before
easing slightly this weekend. Showers will favor windward and
mauka areas, most frequently at night and during the early morning
hours. Late this week into the weekend, an upper-level
disturbance may bring a slight uptick in trade wind shower
coverage.

&&

.DISCUSSION...
Radar and satellite imagery show that a band of moisture
associated with a dissipated surface trough finally lifted north
of Kauai, leaving limited clouds and showers to move into windward
and mauka areas across the state on the breezy easterly trade
wind flow late this afternoon. Ridging at the surface and aloft
will maintain stable, breezy trade wind weather through at least
Wednesday with isolated to scattered showers favoring windward and
mauka areas.

Heading into Friday and the weekend, model guidance suggests that
a mid- to upper-level cutoff low will move over the region,
bringing cooler temperatures aloft and increasing instability. At
the same time, precipitable water values are expected to climb to
1.5 to almost 2 inches over the eastern end of the state as
moisture is drawn up from the south. However, with ridging
expected to persist at the surface, this setup will likely only
amount to an uptick in trade wind shower activity through the
weekend and into early next week, along with ushering in muggier
conditions as dew points climb into the lower 70s. In addition,
the pressure gradient will weaken slightly, allowing the trades to
briefly back off this weekend before strengthening again early
next week.

&&

.AVIATION...
High pressure far north of the islands will maintain a breezy
trade wind pattern over the regions over the next several days.
Mid-level ridging will help to limit shower activity with a stable
airmass in place.

Limited showers will continue to be carried in on the trade winds
flow. At times these showers could bring some mountain obscuration
to various islands, mostly at night and during the morning hours.
Otherwise, VFR conditions are expected to prevail.

AIRMET Tango remains in effect for mechanical turbulence to the
lee of the mountains due to the breezy trade winds. Expect this to
remain in place over the next couple of days.

&&

.MARINE...
High pressure remains in place north of the Hawaiian Islands into
next week, maintaining fresh to locally strong trades through
Thursday. An upper level disturbance will bring an uptick in
shower coverage and weaken the trades Friday into the weekend. The
Small Craft Advisory remains in effect.

A small short to medium period NW (330 deg) swell will slowly
decrease through tonight. A small long period NW swell then arrives
by Wednesday afternoon and peaks on Thursday. Expect small surf
to continue along N and W facing shores.

The small long period S swell declines through the week. Another
small long period S swell arrives on Saturday, maintaining
elevated surf along S shores. Slightly elevated surf along E
facing shores continues until trades weaken this weekend.

&&

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

&&

$$

DISCUSSION...Farris
AVIATION...M Ballard
MARINE...JVC