Waimea, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

805
FXHW60 PHFO 290648
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
848 PM HST Sun Jun 28 2026

.SYNOPSIS...
Moderate to locally breezy trade winds will persist through the
rest of the week. Bands of low clouds and showers will
periodically push across the islands, focusing primarily over
windward and mauka areas during the overnight and early morning
hours. A couple bands of enhanced moisture will move through the
islands tonight through Thursday morning, bringing an increase in
shower coverage and intensity, with some locally heavy rainfall
possible. In addition, humidity levels will rise, bringing muggier
conditions across the island chain through the middle of this week.

&&

.DISCUSSION...
Currently at the surface, a 1038 mb high is centered around 1750
miles north-northeast of Honolulu, driving moderate to locally
breezy trade winds across the island chain this evening. Infrared
satellite imagery shows mostly cloudy to overcast conditions in
windward and mauka areas, while partly to mostly cloudy skies
prevailing in leeward locales. Radar imagery shows numerous
showers moving into windward slopes and coasts, with leeward
spillover on the increase. Main short term focus revolves around
trade wind trends and rain chances.

High pressure will meander north and northeast of state during the
next 7 days, keeping moderate, to at times locally breezy, trade
winds solidly in place. Somewhat wetter than normal, summertime
trade wind weather is expected through the period, with showers
favoring windward and mauka areas, particularly during the night
and early morning hours. A couple bands of enhanced moisture will
affect the state this week, bringing an increase in shower
coverage and intensity. The first batch of enhanced moisture is
already affecting Maui County and the Big Island, and will spread
to the Oahu and Kauai later tonight, remain over all islands on
Monday, then exit to the west Monday night. The next area of
enhanced moisture is located around 700 miles east-northeast of
the state in the vicinity of 145W. Portions of this area of
enhanced moisture will begin to affect the islands Tuesday night
and linger into early Thursday, increasing shower coverage and
intensity once again.

Both these bands will raise precipitable water values into the
1.5 to 2.0 inch range and elevate inversion heights to between 10
and 12 kft. Some locally heavy rainfall can`t be ruled out as
these bands of moisture move through, particularly the second
batch of moisture affecting the islands during the middle of the
week. That said, with the trades in place, a widespread flash
flood threat is not expected, but some minor flooding could very
well necessitate flood advisories over windward and mauka areas
during this time. Additionally, dewpoints are forecast to increase
to around 70 or the lower 70s Monday through the middle of the
week, making it feel more muggy across the island chain.

&&

.AVIATION...
An easterly wave moving through the islands will produce MVFR
conditions and showers across the state through Monday morning.
MVFR conditions could decrease in coverage and frequency by
Monday afternoon. Another low level disturbance will move through
the islands bringing another round of MVFR conditions and showers
from Tuesday night into Thursday.

AIRMET Sierra remains in effect for mountain obscuration above 020
along northern and eastern mountain slopes of most islands. These
conditions will persist through Monday morning, then decrease in
coverage by Monday afternoon.

AIRMET Tango is in effect for moderate turbulence downwind of
terrain due to breezy trade winds and will continue through the
forecast period.

&&

.MARINE...
A high pressure ridge far north of the Hawaiian Islands will
remain nearly stationary this week and keep trade winds blowing
across the region. The Small Craft Advisory (SCA) will continue
through Monday for much of the waters around Oahu, Maui County
and Big Island, as well as the Kaiwi Channel. This is due to brief
boost in wind speeds expected to move in tonight into Monday.

The current long period south swell will maintain through Monday
then gradually decline over the next few days. Another larger
south swell energy pulse will arrive next weekend.

Surf along east facing shores will remain rough and choppy through
the week. Surf heights along north facing shores will remain
nearly flat.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Monday for Oahu Windward
Waters-Kaiwi Channel-Maui County Windward Waters-Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Windward Waters-
Big Island Leeward Waters-Big Island Southeast Waters.

&&

$$

DISCUSSION...Jelsema
AVIATION...Bohlin
MARINE...Thomas