A column of molten rock nearly as tall as a 90-story building could blast out of Kilauea’s summit crater at any point between now and May 7, 2026. The U.S. Geological Survey’s Hawaiian Volcano Observatory opened a formal forecast window for Episode 46 lava fountaining at 1:50 p.m. HST on May 4, after spotting lava spilling over the rim of the summit’s north vent. That overflow has preceded nearly every major fountain burst in the current eruptive cycle, and it prompted HVO to raise Kilauea’s alert level from ADVISORY/YELLOW to WATCH/ORANGE.
For residents of Hawaii Island, pilots crossing the central Pacific, and the thousands of visitors inside Hawaii Volcanoes National Park each week, the upgrade means the volcano is primed to erupt again within days.
45 episodes and counting
Kilauea has been locked in an episodic fountaining pattern since its summit eruption restarted on December 23, 2024. The rhythm is now familiar: magma pressure builds beneath the crater floor, tilt meters record inflation, the north vent overflows, and then a towering lava fountain rips through the surface. After the fountain exhausts the immediate magma supply, the summit deflates, the vent quiets, and the cycle resets.
Forty-five of these episodes have played out over roughly 16 months. Episode 45, which began April 23, 2026, sent fountains to a measured height of 870 feet (265 meters), based on USGS timelapse imagery captured April 24. Episode 44, earlier that month, reached about 800 feet (240 meters) and pushed an ash-and-gas plume to 16,000 feet above sea level, according to NOAA’s Washington Volcanic Ash Advisory Center. That plume triggered aviation ash advisories covering airspace from the surface up to flight level 160.
An HVO update from April 25 confirmed that Episode 45 had paused after summit deflation gave way to renewed inflation, the pressure signature scientists use to project when the next burst will fire. By May 4, that inflation had progressed far enough to produce the north-vent overflow that triggered the Episode 46 forecast.
A 900-foot fountain during Episode 46 would sit squarely within the range established by the two most recent episodes and well below Kilauea’s historical ceiling. During the volcano’s legendary 1959 eruption at Kilauea Iki, fountains reached 1,900 feet, more than double what the current cycle has produced.
What scientists still cannot predict
HVO’s May 4 notice defines when Episode 46 fountaining is likely to begin. It does not forecast how tall the fountains will climb, how long the episode will last, or how much lava will pour onto the crater floor. Those variables depend on magma supply rates, vent geometry, and gas content that can shift rapidly as molten rock moves through Kilauea’s shallow plumbing.
Sulfur dioxide emission rates and detailed seismicity counts specific to the May 4 precursory onset have not yet appeared in HVO’s public volcano messages feed. Once published, those numbers will help clarify whether the magma supply is accelerating compared with prior episodes or holding steady.
Aviation impacts are equally uncertain. NOAA’s Washington VAAC issued ash advisories during Episodes 44 and 45, but no advisory tied to Episode 46 precursors has been released. Whether the next plume matches the 16,000-foot altitude seen in April or climbs higher will depend on eruption vigor and upper-level winds that cannot be forecast days ahead. Airlines operating trans-Pacific routes through Hawaiian airspace, including carriers connecting the U.S. mainland to Asia and Oceania, will be watching for real-time VAAC bulletins once fountaining starts.
Hazards on the ground and in the air
The WATCH/ORANGE alert level signals that elevated hazards to life and property are possible, but HVO has not issued episode-specific evacuation triggers or park closure orders as of the May 4 notice. Hawaii Volcanoes National Park typically adjusts visitor access based on volcanic gas concentrations and tephra fall, and conditions can change within hours once an episode begins.
Where the danger lands depends on two factors: vent location and wind. A fountain confined to the summit crater poses a different threat profile than one that feeds fast-moving lava flows across the caldera floor or down existing drainage channels. Meanwhile, a strong trade-wind pattern could push sulfur dioxide and fine ash toward communities on the island’s leeward side, while lighter or more variable winds might keep most of the plume over the park.
Vog, the hazy mix of sulfur dioxide and fine particulates that Kilauea produces even between episodes, tends to worsen sharply during active fountaining. Residents and visitors with asthma or other respiratory conditions are especially vulnerable. Health officials routinely advise keeping N95 masks and necessary medications accessible and planning to stay indoors during periods of poor air quality. Drivers should also prepare for sudden visibility drops if ash or heavy volcanic haze drifts across highways.
Tracking Episode 46 as it develops
The most reliable source of updates remains HVO’s volcano messages feed, which the observatory refreshes as conditions change, sometimes multiple times per day during active fountaining. NOAA’s VAAC advisories cover airborne ash hazards, and Hawaii County Civil Defense translates both technical streams into plain-language guidance on road closures, safe viewing areas, and air-quality warnings. Hawaii Volcanoes National Park posts its own alerts for visitors through the National Park Service website and on-site signage.
Kilauea’s current eruptive cycle has now stretched past 16 months and shows no sign of winding down. Each episode follows a recognizable buildup, and the signals preceding Episode 46, the north-vent overflow, the rising tilt, the upgraded alert level, match the pattern scientists have documented dozens of times. Another high lava fountain is likely within days. How tall it reaches, how long it lasts, and how far its effects spread will only become clear once the volcano fires.
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*This article was researched with the help of AI, with human editors creating the final content.
