USGS has issued a VOLCANO WATCH for the Big Island of Hawaii and it’s volcano, Kilauea, which is expected to enter into an eruptive phase at any moment. The National Weather Service has also issued a Special Weather Statement for the possibility of volcanic fall-out from this upcoming eruption.

According to the USGS Hawaii Volcano Observatory unit (HVO), an episodic fountaining eruption is expected within the Kilauea summit caldera at anytime, with the forecast potential eruption window between now and June 1. Fountaining episodes typically last less than 12 hours but ash can remain in the air longer depending on wind and weather.

Kilauea has been erupting episodically since December 23, 2024  from two vents  in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses that can be longer than three weeks. This next eruption which could happen at any time and will be the 48th eruptive event of this cycle.

Precursory low-level activity for episode 48 of the ongoing Halemaʻumaʻu eruption at the summit of Kīlauea began around 5:41 pm local time last night with lava overflows from the south vent. Due to the presence of lava at the surface, HVO is raising the Alert Level for Kilauea from ADVISORY to WATCH and the Aviation Color Code from YELLOW to ORANGE.

“This low-level precursory activity can continue for hours to days before the lava fountaining episode beings,” said HVO in a statement today.

In the U.S., the USGS and volcano observatory units are responsible for issuing Aviation Codes and Volcanic Activity Alert Levels. Aviation Codes are green, yellow, orange, or red. When ground-based instrumentation is insufficient to establish that a volcano is at a typical background level of activity, it is simply “unassigned.” While green means typical activity associated with a non-eruptive state, yellow means a volcano is exhibiting signs of elevated unrest above known background levels. When a volcano exhibits heightened or escalating unrest with the increased potential of eruption, it jumps to orange. Finally, when an eruption is imminent with significant emission of volcanic ash expected in the atmosphere or an eruption is underway with significant emission of volcanic ash into the atmosphere, the code becomes red. Volcanic Activity Alert levels are normal, advisory, watch, or warning. As with aviation codes, if data is insufficient, it is simply labeled as “unassigned.” When the volcano is at typical background activity in a non-eruptive state, it is considered normal. If the volcano exhibits signs of elevated unrest above background level, an advisory is issued. If a volcano exhibits heightened or escalating unrest, a watch is issued while a warning is issued when a hazardous eruption is imminent.

While USGS is tracking seismicity and eruptive activity at Kilauea, the National Weather Service is monitoring potentially broader impacts in the atmosphere onto surrounding communities from the eventual eruption.

“If an eruption occurs, varying levels of ash, Pele`s hair, and other lightweight tephra may fall downwind of the eruption. Smaller particles can travel farther from the eruption
site and may affect communities at greater distances,” cautions the National Weather Service office on the Hawaiian Island of Oahu at Honolulu. “Should a higher plume develop during this episode, south- southwesterly  winds aloft could result in an easterly or northeasterly dispersion of ashfall instead.”

The National Weather Service is advising those downwind of the Kilauea summit, or those that plan to visit the summit area, to stay informed about current volcanic activity and
weather conditions. “Be prepared to take precautions if needed, such as disconnecting water catchment systems. Follow all guidance from the National Park Service and the County of Hawaii. Be aware that road or park closures may occur,” the National Weather Service said in today’s special weather statement.

While lava from this next eruption is expected to be contained to the summit caldera, other volcanic debris could travel far from the eruption site. A  major volcanic hazard is fallout of Pele’s hair and other volcanic fragments from lava fountains. Pele’s hair is strands of volcanic glass often produced by lava fountaining activity that can be carried well over 10 miles  from the vent. Other hot glassy volcanic fragments (tephra) including volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1–3 miles  of the eruptive vent(s), with the highest concentrations immediately downwind of the vent(s). Various volcanic fragments have fallen on Highway 11 west of Hawai’i Volcanoes National Park at times, depending on wind and eruption conditions. Strong winds may waft light particles, including Pele’s hair, to greater distances downwind. Once on the ground, Pele’s hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele’s hair deposition is dependent on lava fountaining activity and wind conditions.

USGS urges caution, saying, “Residents and visitors should minimize exposure to Pele’s hair and other glassy volcanic fragments, which can cause skin and eye irritation and can also contaminate catchment water supplies.”

When an ashfall incident is imminent due to some type of explosion at the volcano, the National Weather Service office in Honolulu will issue one of three types of products. The first is a Special Weather Statement.  A Special Weather Statement is issued when there is the potential for trace amounts of accumulating ash. When there’s a chance of a more significant ashfall, from over a trace to up to 1/4″, the National Weather Service will then issue an Ashfall Advisory. And if a heavy ashfall is expected with accumulations greater than 1/4″, an Ashfall Warning is issued.

When any of these products are issued, the National Weather Service encourages people to avoid ash. “Avoid excessive exposure to ash which is an eye and respiratory irritant,” the Special Weather Statement text reads. “Those with respiratory sensitivities should take extra precaution to minimize exposure.”

The International Volcanic Health Hazard Network (IVHHN), the Cities and Volcanoes Commission, GNS Science, and the USGS developed guidelines on preparedness before, during, and after an ashfall.

BEFORE
Stock essential items; a sustained ashfall may keep people housebound for hours or even days. Based on the guidelines you should:

• – have dust masks and eye protection
• – have enough drinking water for at least 72 hours (1 gallon water per person per day)
• – have enough non-perishable food for at least 72 hours for family and pets
• – get plastic wrap to keep ash out of electronics
• – get a battery-operated radio and extra batteries
• – have lanterns or flashlights and extra batteries for both
• – keep extra stocks of medicine for people and pets
• – have a first aid kit
• – prepare cleaning supplies, such as a broom, vacuum cleaner with spare bags and filters, and a shovel
• – get a small amount of cash; sources such as ATMs and banks may not be open
• – consider that you could be stuck in your vehicle, so store emergency supplies in your vehicle too

When a Special Weather Statement, Ashfall Advisory, or Ashfall Warning are issued for your area, take immediate action to protect life and property.

• – close all doors and windows
• – place damp towels at door thresholds and other draft sources, like window cracks
• – protect sensitive electronics and do not uncover until the environment is totally ash free
• – disconnect drainpipes and downspouts from gutters to stop drains from clogging, but allowing ash and water to empty from gutters onto the ground
• – if you use a water catchment system, disconnect the tank prior to the ashfall
• – if you have respiratory illness, such as chronic bronchitis, emphysema, or asthma, stay inside and avoid unnecessary exposure to the ash
• – ensure livestock and pets have clean food and water

DURING
If volcanic ash is falling, stay safe!

• – don’t panic; stay calm
• – stay indoors
• – if outside, seek shelter such as a car or in a building
• – use a mask or cloth over your nose and mouth
• – if a warning is given before ashfall starts, go home from work; if at work when ashdall starts, stay indoors until the ash has settled
• – do not tie up phone lines with non-emergency calls
• – listen to your local radio for information on the eruption and clean-up plans
• – do not wear contact lenses as these will result in corneal abrasion
• – if there is ash in your water, let it settle and then use the clear water. If there is a lot of ash in the water supply, do not use your dishwasher or washing machine. Water contaminated by ash will usually make drinking water unpalatable before it presents a health risk
• – you can eat vegetables/fruit from outside, but wash ash off first

Volcanic ash, even in small quantities, can do harm on the surface. A light coating on car or home windows can scratch them; great care should be used when removing ash. Ash entering water catchment systems can contaminate their contents, clog filters,  and/or do harm to pumps. More substantial eruptions can also impact cars and jet aircraft.

The National Weather Service says in the event Kilauea creates a large ash loud, NOAA’s  Volcanic Ash Advisory Centers (VAAC) will issue critical guidance to help aircraft steer away from destructive ash particles. NOAA’s VAAC has been providing guidance on remote volcanoes erupting in/around Alaska that could pose an aviation threat too.