Ashfall Advisory 6, NWS Honolulu, HI

110 
WWHW70 PHFO 231904
NPWHFO

URGENT - WEATHER MESSAGE
National Weather Service Honolulu HI
904 AM HST Thu Apr 23 2026

HIZ051-052-240400-
/O.EXT.PHFO.AF.Y.0006.000000T0000Z-260424T0400Z/
Big Island South-Big Island Southeast-
904 AM HST Thu Apr 23 2026

...ASHFALL ADVISORY NOW IN EFFECT UNTIL 6 PM HST THIS EVENING...

* WHAT...Kilauea is erupting lava fountains within the summit 
  caldera. Fountaining episodes typically last less than 12 hours 
  but ash can remain in the air longer depending on wind and weather 
  conditions.

* WHERE...Big Island South and Big Island Southeast.

* WHEN...Until 6 PM HST this evening.

* IMPACTS...The public will be affected by a limited hazard extent. 
  Varying levels of tephra, including ash, Pele’s hair and other 
  lightweight pumice may fall downwind of the eruption. These small 
  particles are eye and respiratory irritants, but will have low 
  level impacts for most people.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Limit exposure to tephra, especially if you have respiratory 
sensitivities. Wear a mask, gloves, eye protection, and long 
clothing when clearing ashfall. Close windows and doors. Cover and 
disconnect water catchment systems to protect your water supply.

&&

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

  Hawaiiash.science/report_form

$$

Walsh

639 
WWHW70 PHFO 232014
NPWHFO

URGENT - WEATHER MESSAGE
National Weather Service Honolulu HI
1014 AM HST Thu Apr 23 2026

HIZ051-052-232115-
/O.CAN.PHFO.AF.Y.0006.000000T0000Z-260424T0400Z/
Big Island South-Big Island Southeast-
1014 AM HST Thu Apr 23 2026

...ASHFALL ADVISORY IS CANCELLED...

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

$$

Walsh

Area Forecast Discussion
National Weather Service Honolulu HI
853 PM HST Wed Apr 22 2026

.SYNOPSIS...
A surface ridge building north of the islands will allow moderate
trade winds to return to the islands Thursday. Rainfall will be
limited into the weekend due to an upper level ridge over the
islands. However low level moisture riding in on the trades will
bring more typical windward and mauka showers by the end of the
weekend.

&&

.DISCUSSION...
No updates to the forecast this evening, and not expecting any
significant changes with the morning package.

A low pressure system more than 700 miles northeast of the
islands, combined with a surface trough about 600 miles to the
north, are helping to maintain the lighter winds over the region
this evening. Clouds are clearing out in the light wind pattern
over the islands, and satellite shows few clouds near the islands.

The low and trough are expected to dissipate over the next 24
hours, and that will allow a surface ridge to build back in north
of the islands. This in turn will allow moderate trade winds to
build back in at the surface. The global models agree on mid
level ridging over the region which will help to maintain a stable
airmass, thereby limiting shower activity over the next few days.

The global models are in good agreement that moisture from the
above mentioned low will get caught up in the trade wind flow over
the weekend, and late in the weekend, make its way into the
islands. This will help us return to a more typical trade wind
weather pattern with some showers over the windward and mauka
areas, along with the clouds and showers that form over the Kona
slopes during the afternoon.

&&

.AVIATION...
Northeasterly trade winds will fill in tonight becoming moderate
tomorrow and focus most showers over windward and mountain areas.
VFR conditions will prevail with brief MVFR conditions any in
showers.

No AIRMETs in effect.

&&

.MARINE...
Trade winds will be making a come back through Thursday in
response to an upper ridge building in west of the islands. The
associated surface high will travel across to the north of the
waters and be northeast of the state by early next week. This will
produce a tight enough Central Pacific pressure gradient to
maintain moderate to locally fresh trades Thursday and Friday.
Trades will persist through the weekend as another high passes
north of the state. Brief periods of locally strong winds will be
possible this weekend over the windier areas surrounding Maui
County and Big Island.

A moderate size, medium period northwest swell that peaked
early today will gradually decline the next few days. A pair of
North Pacific gale lows will send a series of small north to
northwest swells down into the local waters from Friday night
through the first half of next week. These swells will likely
maintain near to slightly below average north-facing shore surf
into next week.

A moderate size, medium period north northeast swell that quickly
filled in last night and peaked during the day introduced advisory
level surf along many northeast to eastern exposures, as well as
lifting surf to above average heights along some select western
shores in Maui and Big Island. This swell will slowly decline
through the remainder of the week. Moderate to fresh trades this
weekend will support near seasonal average east-facing shore wind
wave surf.

Small background energy from the west will continue to linger
the next few days and fade out this weekend. A small southwest
bump from very faded Tasman Sea energy is expected to arrive this
weekend. No significant south swells are expected through the
first half of next week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory until 6 AM HST Thursday for Big Island East-
Big Island North-Big Island Southeast-Kipahulu-Koolau Windward-
Molokai Southeast-Molokai Windward-Olomana-Windward Haleakala.

&&

DISCUSSION...M Ballard
AVIATION...Tsamous
MARINE...Blood