The sun fired a powerful M5.7 solar flare on Saturday May 10, 2026, launching a fast-moving coronal mass ejection, a massive cloud of charged particles, into space at approximately 650 kilometers per second.
Most of that cloud is heading east of Earth and will miss our planet entirely. But forecasters at NOAA’s Space Weather Prediction Center and the UK Met Office have identified a glancing blow scenario.
The outer edge of the expanding cloud is expected to brush past Earth early on Wednesday May 13, and the window for seeing northern lights as a result of that encounter is open tonight and through Tuesday night into Wednesday.
The geomagnetic storm that a glancing blow of this kind produces sits in the G1 category, the lowest of five storm levels.
That means the aurora borealis will not be pushing into the lower 48 states the way it did during the extraordinary G5 event of May 10, 2024.
This is a more modest event. But if you are in the northern United States, Scotland, or other high-latitude regions and you have clear skies tonight, the odds of seeing something are real and worth knowing about.
What The Sun Did On May 10
The flare that launched this week’s aurora possibility erupted from a sunspot region called AR4436, located in the northeast portion of the visible solar disk, at 9:39 AM Eastern on May 10.
It peaked at M5.7 strength, the M classification covers moderate-to-strong flares, with the number indicating intensity within that range.
An M5.7 is powerful enough to knock out high-frequency radio communications and significant enough to drive a CME launch.
Solar flares are rated on a five-category scale, A, B and C for minor events, M for moderate, and X for extreme.
Each step up the scale represents a tenfold increase in energy output.
An M5.7 sits in the middle of the moderate range and is capable of real-world disruption, which is exactly what happened immediately after the May 10 eruption.
NOAA classified the associated radio blackout as R2, a moderate disruption to high-frequency radio communications across the Atlantic Ocean.
Mariners navigating open ocean, aviators on transatlantic flight paths and amateur radio operators all experienced disrupted communications as the flare’s X-ray and ultraviolet radiation ionized the upper layers of Earth’s atmosphere and scrambled the signals that travel through it.
That ionization effect travels at the speed of light, it reached Earth approximately eight minutes after the flare peaked.
The CME that followed takes considerably longer. Solar plasma traveling at 650 kilometers per second still requires one to three days to cross the 93 million miles between the sun and Earth.
The expected arrival window for whatever Earth-directed component exists in this CME is early on May 13, making the overnight window of May 12 into May 13 the most relevant time frame for aurora watchers.
The Glancing Blow Scenario Explained
The phrase “glancing blow” is the important modifier in everything being said about this week’s aurora potential.
The WSA-ENLIL model used by NOAA to project CME trajectories indicates that the bulk of the ejected material is heading east of Earth’s orbit, it will pass behind our planet and miss entirely.
What the model suggests may still reach Earth is the outer edge of the expanding plume, not the dense core of the eruption.
The practical consequence is a G1 geomagnetic storm rather than the G3 or G4 conditions that produce widely visible aurora displays.
At G1 conditions, with a Kp-index reaching approximately 5, the auroral oval, the band of atmospheric glow that circles Earth’s polar regions, expands modestly beyond its typical boundaries.
People at high latitudes who already see the northern lights occasionally will have an enhanced viewing opportunity.
People at mid-latitudes in the northern hemisphere are looking at a long shot rather than a likely sighting.
The UK Met Office and NOAA both acknowledge significant uncertainty in this forecast. The CME may deliver a weaker disturbance than modeled. It may miss Earth entirely.
The forecast remains somewhat uncertain specifically because of the glancing trajectory, the edge of a CME cloud is harder to model accurately than a direct hit.
Where You Can See The Northern Lights Tonight
If geomagnetic conditions develop as forecast, G1 storm, Kp around 5, the aurora borealis will be visible from high-latitude locations.
In the United States, that means the Pacific Northwest (Seattle area), the northern tier of the Midwest (Minneapolis and north), northern New England and Alaska.
In the United Kingdom, Scotland is the primary viewing zone, the Scottish Highlands and Edinburgh are the locations where G1 aurora visibility is most reliable. Scandinavia, Iceland, northern Canada and other Arctic-adjacent regions will have the best viewing regardless of the storm’s exact intensity.
At Kp 5, the aurora does not typically reach Chicago, New York or London.
The aurora forecast for major mid-latitude cities in the continental United States remains low probability for this event.
The May 2024 G5 storm that made aurora visible in Florida and Texas was an entirely different category of event, that storm registered at the maximum level of the geomagnetic storm scale and produced auroras visible as far south as Mexico.
This week’s glancing blow is not in that category.
For those in the right locations, the ideal viewing conditions are, clear skies, a dark location well away from city lights, a clear view of the northern horizon and patience.
The aurora often appears faint to the naked eye even when cameras capture it clearly, modern smartphone night mode and long-exposure photography can reveal colors and detail the eye alone misses.
The best time to look is after 10 PM local time when the sky is fully dark, and particularly in the early hours of May 13 when the CME is expected to be interacting most directly with Earth’s magnetic field.
The Solar Maximum Context
This week’s flare and CME are not random events. They are part of a broader pattern that makes 2026 the most active period for solar weather in roughly a decade.
The sun operates on an approximately 11-year cycle of activity, moving from Solar Minimum, when sunspot activity is low and flares are rare, to Solar Maximum, when the solar surface is covered in active regions and significant events happen regularly.
2026 sits at or near the peak of Solar Cycle 25, the Solar Maximum.
During Solar Maximum, X-class flares, the highest category, become more frequent. CMEs are launched more often and with more energy.
The aurora borealis appears at lower latitudes more regularly. The charged particle environment through which satellites, spacecraft and astronauts operate becomes more hazardous.
The potential for significant geomagnetic storms disrupting power grids and GPS systems increases.
The extraordinary G5 storm of May 10, 2024, which produced aurora displays visible across virtually the entire continental United States, much of Europe and even parts of the Southern Hemisphere, happened exactly two years ago this week and served as the single most dramatic demonstration of what Solar Maximum conditions can produce.
That storm remains the benchmark against which all current solar activity is measured.
The current M5.7 event is considerably weaker and the expected impact considerably smaller.
The fact that AR4436 remains active and is gradually rotating toward more direct Earth alignment means forecasters are watching closely for whatever the region produces next.
Whether that next eruption delivers another glancing blow or something more significant depends entirely on the timing and trajectory of the sun’s next move.
How To Follow The Aurora Forecast In Real Time
NOAA’s Space Weather Prediction Center updates its aurora forecast continuously at swpc.noaa.gov.
The primary metric to watch is the Kp-index, a scale from 0 to 9 that measures geomagnetic activity.
A Kp of 5 represents the G1 storm threshold. A Kp of 7 or higher starts pushing aurora visibility into the lower 48 states at lower latitudes.
When the Kp index at swpc.noaa.gov reads 5 or above, people in the northern-tier states have a genuine aurora viewing opportunity.
SpaceWeather.com and the EarthSky aurora forecast blog are also reliable real-time tracking resources for anyone planning to watch. Both update frequently when active space weather is underway.
The specific window to watch is tonight through early Wednesday May 13. After that, unless AR4436 produces another eruption, geomagnetic conditions are expected to gradually settle back toward quieter levels.
