At 1:38 a.m. Hawaii time on Sunday, May 4, 2026, lava spilled over the rim of the north vent inside Halemaʻumaʻu crater, the first visible sign that Kilauea’s 46th eruptive episode since late 2024 was loading up. Within hours the Hawaiian Volcano Observatory bumped the alert level from ADVISORY to WATCH and switched the aviation color code from YELLOW to ORANGE, signals that tell emergency managers and airline dispatchers the same thing: something significant may be about to happen, and the clock is ticking.
The official forecast window runs through May 7. The last time Kilauea opened up, during episode 45 roughly a week earlier, lava fountains from the same vent reached approximately 900 feet (270 meters), with wispy spray stretching above 1,000 feet, according to HVO’s episode 45 summary. The eruption column climbed to roughly 20,000 feet above sea level, high enough to graze trans-Pacific flight corridors and carry fine ash far downwind of the summit, as documented in a separate HVO plume advisory.
Those numbers make episode 46 worth watching closely, because the trend line across this eruptive cycle has been pointing upward.
A cycle that keeps getting more intense
Kilauea’s current run of episodic eruptions began on December 23, 2024. Rather than one continuous flow, the volcano has been firing off discrete bursts, each separated by days or weeks of relative quiet while pressure rebuilds beneath the summit. The USGS maintains a public eruption-information timeline logging start and stop times, approximate fountain heights, and estimated lava volumes in millions of cubic meters for every episode.
That dataset tells a clear story: several episodes in early 2026 surpassed the heights and volumes recorded during the first months of the sequence. Episode 43 set the cycle’s fountain-height record and scattered tephra, fragments of volcanic rock and glass, across nearby communities including parts of the Volcano Village area southwest of the crater. HVO’s Volcano Watch analysis paired field measurements with eyewitness accounts and photographs to document the fallout, and NASA’s Earth Observatory independently captured the event using Landsat 9 imagery, showing a broad plume and incandescent fountains visible from orbit.
Episode 45 then delivered the 900-foot fountains that have become the benchmark heading into this week. Taken together, the record suggests Kilauea’s shallow plumbing system is cycling through pressurization-and-release phases that have grown progressively more energetic, though scientists caution that past performance does not guarantee future intensity.
What HVO has confirmed about episode 46
The agency’s formal notice for episode 46 confirms the precursory overflow from the north vent, the 1:38 a.m. HST onset, and a forecast window based on summit tilt changes and increasing seismic tremor. That same notice triggered a Volcano Observatory Notice for Aviation (VONA), the standardized alert that warns pilots and dispatchers of possible ash and gas hazards at flight levels.
Three facts stand out from the official record so far:
- The volcano is in an active eruptive phase defined by short, intense episodes rather than a single sustained eruption. Each quiet interval is not a return to dormancy but a recharge period.
- The summit system can produce very tall fountains and high plumes. Episodes 43 and 45 proved that convincingly, with plumes reaching altitudes relevant to commercial aviation.
- The transition from quiet to violent can happen in hours. HVO’s pre-dawn alert-level change on May 4 underscores how quickly conditions can shift, which is why the WATCH/ORANGE designation carries real operational weight.
What scientists do not yet know
No official estimate exists for episode 46’s potential fountain height or lava volume. HVO’s eruption-information hub currently lists data only through episode 45, and the agency has not published any forward-looking projections. The idea that this episode “could be bigger” rests on the observed trend of escalating intensity, not on a specific forecast model or quantitative prediction.
Even the episode 45 measurements carry some built-in ambiguity. One HVO update cited a maximum fountain height of 900 feet; another described the main fountain body as at least 700 feet with wispy trails above 1,000 feet. The discrepancy reflects the difficulty of defining where a coherent jet of molten rock ends and wind-shredded spray begins. Camera angle, lighting, and plume opacity all influence the call, and HVO notes that many values in its timeline are approximate and subject to revision.
Detailed seismic amplitudes, sulfur dioxide emission rates, and ground-deformation data for the episode 46 buildup have not appeared in public notices beyond general references to tilt, glow, and tremor. Those granular readings typically surface in technical summaries published after an episode concludes, which means anyone tracking the buildup in real time is working with broad qualitative descriptions rather than instrument graphs.
What this means for Big Island residents and travelers
As of the start of the forecast window, no community-specific evacuation orders or ashfall advisories have been issued for episode 46. Hawaii Volcanoes National Park continues to post general safety guidance, including staying out of closed areas and avoiding low-lying spots where sulfur dioxide and other volcanic gases can pool. But targeted warnings for particular neighborhoods depend on wind direction, plume height, and eruption intensity, none of which can be pinned down until sustained fountaining actually begins.
Downwind communities have reason to pay attention. When trade winds blow from the northeast, as they typically do, volcanic emissions and fine ash drift southwest toward Pahala and other Ka’u District towns. A shift in wind patterns can push vog (volcanic smog) and lightweight debris like Pele’s hair, thin strands of volcanic glass that can irritate skin and lungs, toward Hilo or Kona-side communities instead. During episode 43, tephra fall was significant enough to prompt HVO to issue specific guidance for affected areas.
For travelers with flights through Hilo or Kona, the ORANGE aviation color code means airlines and the Federal Aviation Administration are actively monitoring conditions. Ash clouds at 20,000 feet can damage jet engines and abrade windshields, so route adjustments or brief ground stops are possible if a high plume develops. Checking airline and FAA advisories before heading to the airport is the simplest precaution.
What to watch for through the May 7 forecast window
The forecast window closes May 7, but Kilauea does not operate on a schedule. Episode 46 could produce towering fountains that dwarf the 900-foot mark, or it could fizzle into a modest overflow that barely registers beyond the crater rim. The honest answer is that nobody, including the scientists stationed at HVO, knows yet which scenario will play out.
What is knowable: the USGS will issue updated notices as conditions evolve, and those notices remain the most reliable source of information. HVO’s webcams, updated every few minutes, offer a live window into the crater for anyone who wants to watch the buildup unfold. Local civil defense agencies will push alerts through Hawaii’s emergency notification system if ashfall or gas hazards threaten populated areas.
Kilauea’s recent track record argues for taking the forecast window seriously. The volcano has repeatedly shown it can go from precursory glow to 900-foot fountains in a matter of hours, and the overall trend across this eruptive cycle has been toward bigger, not smaller, events. Staying tuned to HVO’s Kilauea page and respecting park closures are the most practical steps until the volcano makes its next move.
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*This article was researched with the help of AI, with human editors creating the final content.
