Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 07/31/2026 04:27:00 PM UTC

                        
215
FXHW60 PHFO 310627
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
827 PM HST Thu Jul 30 2026

.SYNOPSIS...
A strong high will build north of the state while remnants of
Fausto continues to weaken and shifts far northwest. Breezy
easterly trades will strengthen to locally windy levels Friday
afternoon and evening then hold into Saturday. A drier and more
stable airmass will also settle in over the state that could
produce very windy downsloping winds that may warrant a Wind
Advisory. Trades will ease back to the usual breezy levels Sunday
into early next week as the high weakens. Typical summertime
showers are expected for windward and mountain areas.


&&

.SHORT TERM UPDATE...
This evening`s IR satellite imagery loop shows unorganized layered
clouds with isolated embedded convection, associated with the
remnants of former TC Fausto, several hundred miles northwest of
the Hawaiian islands. Closer to state, scattered low level clouds,
caught up in the trades, can be seen drifting towards windward
locations. Shower activity since noon generally produced only a
few hundredths of an inch of rain at select windward locations.
The outlier was a gauge just northwest of Waimea, on the Big
Island, where a third of an inch of rain was reported. Hi- res
models show more of the same tonight with isolated to scattered
showers pushing up against the windward slopes in moderate to
locally breezy trade flow. In the evening update, the chance of
precipitation was lowed slightly for the south Kona slopes on the
Big Island, but cloud cover was increased to account for current
trends. Otherwise, the rest of the forecast appeared on track.

&&

.PREV DISCUSSION...
Issued at 347 PM HST Thu Jul 30 2026

A surface high far north of the state is driving breezy easterly
trade winds across the state. Satellite and radar show scattered
clouds with limited light showers mainly along windward and mauka
areas, with minimal rainfall statewide this afternoon. The high
will strengthen tonight through Friday as remnant low Fausto
weakens far northwest of the state. Expect an increase in clouds
and showers mainly along windward and mauka tonight as a low level
deck of clouds and showers moves from east to west.

Breezy to locally windy trades are expected Friday afternoon into
Saturday under a dry and stable airmass that will lower inversion
heights to around 5,000 ft. Under these conditions winds could be
accelerated downslope, near mountain tops and ridges, through
gaps in the terrain, and in areas typically exposed to the trade
winds that may warrant a wind advisory. However, uncertainty
remains between the high resolution model guidance running a
little stronger and earlier than the global models. With the drier
airmass, dewpoints are expected to dip below 70 degrees, offering
relief from the recently hot and muggy conditions.

Trades will weaken to moderate to locally breezy levels Sunday
into early next week as Hurricane Genevieve tracks far northeast
of the state, disrupting the trade wind flow. Another round of
hot, muggy conditions could develop by the mid-week as remnant
moisture from Genevieve moves over the state.

&&

.AVIATION...
Moderate to breezy trade wind weather will prevail through the
period. Occasional MVFR ceilings and lowered visibilities over
windward and mauka areas may occur within brief, heavier showers.

No AIRMETs are currently in effect. Friday`s lower level trades
may strengthen enough to warrant an AIRMET TANGO across and
immediately S through W of high terrain.


&&

.MARINE...
Trades strengthen into Friday in support of the current Small
Craft Advisory (SCA). Further expansion of the SCA may be
warranted as strong trades become established this weekend.

The current medium period S swell will fade through the weekend.
A mix of small south swells over the next few days will maintain
surf along S facing shores slightly below the seasonal average.

An E swell will arrive tonight and persist through the weekend.
This swell is a combination of the short period trade wind swell
and the medium to long period east swell generated by Hurricane
Genevieve in the East Pacific. N shores will see flat to tiny surf
through early next week.


&&

.FIRE WEATHER...
Issued at 347 PM HST Thu Jul 30 2026

Breezy trades will continue to strengthen to locally windy levels
across the state by Friday afternoon and evening. A drier and
more stable airmass will drop inversion heights to around 5,000 ft
Friday afternoon into Saturday that could further accelerate
winds downslope, along mountain tops and ridges and through gaps
in the terrain. With the low inversion heights, chances of
precipitation will be low and limited to windward areas. While
KBDI will remain below the critical thresholds this hot, dry and
windy pattern could make for some near critical fire weather
concerns, especially for areas above the inversion height and in
the windier areas. Trades are expected to return to more normal
moderate to locally breezy levels Sunday into early next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory from 4 AM Friday to 6 AM HST Saturday for
Big Island Windward Waters-Kaiwi Channel-Maui County Leeward
Waters-Maui County Windward Waters.

Small Craft Advisory until 6 AM HST Saturday for Alenuihaha
Channel-Big Island Leeward Waters-Big Island Southeast Waters-
Maalaea Bay-Pailolo Channel.


&&

$$
SHORT TERM UPDATE...Thomas
DISCUSSION/FIRE WEATHER...Almanza
AVIATION...Blood
MARINE...JVC