Forecasters say a fresh burst of solar energy could send subtle curtains of colour rippling south, with viewing chances rising after dusk and improving into the small hours. The window is narrow, the weather fickle, and the pay-off could be memorable for those who plan ahead.
Where and when to look
NOAA has issued a moderate geomagnetic storm watch for Thursday night into early Friday, tied to several coronal mass ejections launched between 11 and 13 October. The agency expects the geomagnetic Kp index to flirt with the mid‑5s, a level that can push auroras beyond their usual polar haunts.
Prime window: 5–11pm Eastern Daylight Time (21:00–03:00 GMT on 17 October), with peaks likely late evening into the first post‑midnight hour.
Activity tends to ebb and flow. A quiet hour can give way to a sudden outburst. Keep your expectations nimble and your eyes adapted to the dark.
States within the potential viewing zone
Based on the latest aurora probability maps, the following 15 states sit fully or partly inside the likely viewing band:
- Alaska
- Washington
- Idaho
- Montana
- North Dakota
- South Dakota
- Minnesota
- Wisconsin
- Michigan
- New York
- Maine
- New Hampshire
- Vermont
- Wyoming
- Iowa
Skies must cooperate. Cloud cover, haze and city glow will erase even a decent aurora. Aim for a dark northern horizon, away from streetlights, football grounds and busy roads.
What to watch for in the sky
At lower latitudes, the aurora often appears as a pale arc low to the north. Your camera may see stronger colours than your eyes at first. During bursts, the arc can brighten, unfurl into bands and form gentle spires that rise and fade like breath on glass. Green dominates at these latitudes, with occasional hints of pink or purple along active edges.
If you think you see a faint grey cloud that does not drift, take a 3–5 second photo. If it glows green on the screen, you have found it.
Be patient. Stand still for ten minutes and let your night vision grow. Glance sideways rather than staring straight on; peripheral vision is more sensitive in the dark.
How to give yourself the best chance
- Leave bright areas behind. A country lane or lakeshore with a clear northern view works well.
- Check local cloud forecasts hourly; gaps can form quickly after sunset.
- Start watching at dusk and keep an eye on the north until at least midnight.
- Let your eyes adjust for 15 minutes. Dim your phone screen to the lowest setting.
- Dress in layers and bring a hot drink; comfort keeps you out longer when the burst arrives.
- Use a tripod or rest your phone on a solid surface to avoid shake during long exposures.
Why the activity is up tonight
Several coronal mass ejections left the Sun in quick succession earlier this week. When these clouds of magnetised plasma arrive close together, their effects can stack, amplifying turbulence in Earth’s magnetic field. That turbulence channels charged particles towards the upper atmosphere, where they strike oxygen and nitrogen and trigger the familiar glow.
The timing also fits the broader arc of solar cycle 25, which is nearing its peak. More sunspots mean more frequent eruptions, and that means more chances for mid‑latitude auroras through the coming months.
Multiple solar eruptions arriving hours apart can produce a stepped storm, with several peaks rather than one brief surge.
Understanding the scales and what they mean
Two numbers matter for night watch planning: Kp, which rates geomagnetic disturbance from 0 to 9, and the G‑scale, which translates that disturbance into impact categories from minor to extreme.
| Kp | G‑scale label | Typical visibility band |
|---|---|---|
| 5 | G1 minor | Northern tier states and southern Canada |
| 6 | G2 moderate | Deeper into the northern plains and Great Lakes region |
| 7 | G3 strong | Occasional dips towards the central states |
Tonight’s forecast hovers around mid‑5 on the Kp scale, roughly in the G2 bracket. That places the likely viewing line across the northern states listed above, with a chance for brief southward dips during peaks.
Photography quick start for phones and cameras
Modern phones are surprisingly capable. Activate night mode, set a 3–10 second exposure, use the widest lens and prop the device steady. If your phone allows manual control, try ISO 800–1600, exposure 5–8 seconds, focus locked to distant lights, and a two‑second timer to avoid shake.
For mirrorless or DSLR users, start at ISO 1600, f/1.4–f/2.8 and 4–8 seconds. Shorten exposures if pillars smear; lengthen them if the arc looks faint. Shoot in raw, and keep spare batteries warm in an inner pocket.
What could go wrong and how to adapt
Clouds often arrive at the wrong moment. Scan satellite imagery for breaks and be ready to move 15–30 minutes by car to reach clearer skies. Smoke, haze and sea fog will mute colour. Wind can shake tripods; lower the centre column and weigh it down with a bag.
Stray light can trick you. Car headlights will wash the scene for minutes. Shield your view with your body and wait for darkness to return. If the arc fades, do not leave immediately; activity often rebounds within half an hour.
Everyday effects you might notice
At this level, most impacts remain subtle. Power operators may manage small fluctuations. High‑frequency radio can suffer patches of interference at high latitudes. GPS accuracy can wobble by a metre or two, especially near dawn and dusk, and satellites can feel a touch more atmospheric drag. For the average stargazer on the ground, the main effect is a better‑than‑usual chance of a show.
If you miss it tonight
Geomagnetic storms arrive in pulses, and several solar eruptions launched this week could prolong the window into tomorrow morning. With the solar cycle running hot, more opportunities will follow through autumn and winter, when nights lengthen and air cools. Keep a small kit ready—head torch with red mode, handwarmers, lens cloth, spare power bank—and a shortlist of nearby dark‑sky spots so you can set off at short notice.
Key terms, made simple
Coronal mass ejection: a cloud of charged gas hurled from the Sun, carrying its own magnetic field. When it connects well with Earth’s field, auroras brighten. Kp index: a measure of geomagnetic disturbance from 0 (quiet) to 9 (severe). Viewing line: an estimate of how far from the pole auroras might be seen under clear, dark conditions. None of these guarantees a display, but together they guide your decision to head out.
