Ashfall Advisory 7, NWS Honolulu, HI

391 
WWHW70 PHFO 060531
NPWHFO

URGENT - WEATHER MESSAGE
National Weather Service Honolulu HI
731 PM HST Tue May 5 2026

HIZ052-053-060645-
/O.EXP.PHFO.AF.Y.0007.000000T0000Z-260506T0600Z/
Big Island Southeast-Big Island East-
731 PM HST Tue May 5 2026

...ASHFALL ADVISORY WILL EXPIRE AT 8 PM HST THIS EVENING...

The threat has ended.

Submit your reports and photos of ashfall from volcanic eruptions to 
the USGS Hawaiian Volcano Observatory at:

  Hawaiiash.science/report_form

$$

GIBBS

Area Forecast Discussion
National Weather Service Honolulu HI
339 AM HST Tue May 5 2026

.SYNOPSIS...
Light winds, increasing humidity, and land and sea breeze
conditions will persist through midweek as a series of fronts
pass north of the state. Showers will remain brief and primarily
over interior and leeward areas during the afternoons. Rainfall
chances may increase by the weekend as an upper disturbance
approaches the region.

&&

.DISCUSSION...
The subtropical ridge will remain weak through midweek as a
series of cold fronts pass well north of the state. This pattern
has disrupted the typical trade wind flow, allowing land breezes
to develop overnight into this morning. A more humid air mass
will settle over the islands, with dewpoints climbing into the
upper 60s.

These elevated dewpoints, combined with a weak front in the
vicinity and afternoon sea breeze development, will support
localized cloud buildups and scattered showers over interior and
leeward areas each afternoon. Clearing is expected overnight as
land breezes reestablish.

By the latter part of the week into the weekend, moisture and
rainfall chances may increase. Global guidance indicates lowering
heights aloft as an upper-level disturbance and its attendant cold
front approach and move into the area. Uncertainty, however,
remains high due to differences in model solutions regarding the
timing and strength of these features, resulting in low confidence
in the details.

&&

.AVIATION...
Trades will continue to weaken over the coming days, resulting in
sites seeing more of a land/sea breeze pattern, especially by the
evening. In the meantime, windward showers are expected to
persist, with MVFR conditions possible at times due to low clouds
and degraded visibilities.

AIRMET Sierra remains in effect for windward Maui and the Big
Island due to mountain obscuration. Conditions may improve by
daybreak, but satellite imagery suggests that low-level moisture
and clouds may persist into the afternoon hours.

&&

.MARINE...
The trades will ease and shift southeasterly at light to moderate
levels today and tonight as an approaching front merges with a
trough north of the island chain. The front will pass north of
the area on Wednesday, bringing light and variable winds, with sea
and land breezes present near the immediate coasts. A new high
building northwest of the state will bring a return of light to
moderate trades Thursday and Friday, with the trades strengthening
to moderate and fresh levels over the weekend. Winds and seas are
expected to remain below Small Craft Advisory thresholds through
at least Friday.

A moderate medium-period northwest swell will gradually lower
during the next couple of days. A new long period swell will build
Wednesday night and give a nice boost to north and west shore surf
Thursday and Friday, followed by a gradual decline over the
weekend into early next week.

A series of overlapping south swells will keep steady small surf
rolling into south facing shores during the next week.

Surf along east facing shores will remain below normal during the
next 7 days due to the lack of strong trades over and upstream of
the islands.

&&

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

&&

DISCUSSION...Gibbs
AVIATION...Evans
MARINE...Jelsema