Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 04/15/2026 06:16:00 AM UTC

                        
905
FXHW60 PHFO 142016
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
1016 AM HST Tue Apr 14 2026

.SYNOPSIS...
Light to moderate rain continues over the western portion of the
state. Periods of showery, somewhat unstable conditions are
expected to persist through much of the week. Light and variable
winds may also promote localized land and sea breeze development.
By the latter half of the week, a return to light east to
southeast winds will bring generally quieter weather, however,
shower activity could increase by the weekend as an upper-level
trough approaches from the northwest.

&&

.SHORT TERM UPDATE...
Issued at 1010 AM HST Tue Apr 14 2026

This morning`s REFS model continues to show an increase of showers
over Kauai today especially during the afternoon and evening.
While rain is expected to increase, rainfall rates will likely
remain modest due to the lack of atmospheric dynamics. Even with
the lack of dynamics, a few inches of rain will be possible over
the next 24 hours for Kauai. Elsewhere across the state, sea
breezes will develop by mid day today and we should see clouds and
showers develop over interior areas this afternoon. With
precipitable water values higher than normal, some brief downpours
are expected at times this afternoon and evening.

&&

.DISCUSSION...
Issued at 341 AM HST Tue Apr 14 2026

The main shower band has drifted eastward from the previous
forecast and is now located over Maui County and the Alenuihaha
Channel. Rainfall rates from these showers have been producing
below a tenth of an inch per hour. The subtropical jet, currently
located just north of the Hawaiian Islands and drifting southward,
will help steer these intermittent shower bands over the region
for the next several days. Cloud coverage will also be maintained
through much of the week, ensuring dewpoints remain high in the
upper-60s, leading to noticeably humid conditions. With the
lighter surface winds in the forecast, initially from the
southeast before becoming variable, any diurnal heating will be
enough to trigger land and sea breeze activity. This may bring
leeward and interior showers throughout the day, and partial
clearing overnight for most of the islands. Otherwise, these weak,
intermittent shower bands will persist as they ride the
subtropical jet following the southwesterly flow aloft.

Toward the latter half of the week, the surface low pressure
system, once anchored just north of the islands, will finally
dislodge and move northeastward opening the doors for high
pressure to quickly build in its place. Light trades attempt to
develop in response, however, latest model guidance depicts an
upper-level trough digging down into the vicinity of the state
from the northwest. While not overly impressive, nor super
impactful currently, it is expected to limit the strength of the
trades. That being said, it is worth keeping an eye on the
evolution of the upper-level trough to determine if it enhances
the ongoing shower activity (especially with the lingering
moisture-laden airmass across the state), or if it is simply
passing through.

.AVIATION...
Issued at 341 AM HST Tue Apr 14 2026

Low cigs and isol SHRA will continue across the islands. MVFR
conds possible but VFR should prevail. Winds will generally be
driven by land-sea breezes. The forecast generally trends back
toward trades tomorrow into Thursday.

No AIRMETs in effect.


&&

.MARINE...
Issued at 341 AM HST Tue Apr 14 2026

A weak surface trough will reside just west of the state through
Thursday. This will allow for gentle southeast flow across the
waters and locally moderate easterly flow in the typical windy
channels surrounding Maui and the Big Island. Surface high
pressure building far north of the region will help tighten the
pressure gradient and bring moderate to locally fresh easterly
trades across the Hawaiian coastal waters Friday into this
weekend.

A small, short-period, northwest swell will continue to slowly
diminish through the rest of the week and into the weekend.

A small, medium-period, south swell has arrived at the near shore
buoys and should provide a boost to surf along south facing
shores through late week before gradually subsiding into the
weekend.

Surf along east facing shores will remain below seasonal average with
lighter than average trade winds near and upstream of the islands
forecast through late this week. A slight bump up in surf may
occur Friday into this weekend with the increase of easterly flow.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...Kino
DISCUSSION...Pierce
AVIATION...Walsh
MARINE...Thomas