Three coronal mass ejections fired from the sun over the past 48 hours are now racing toward Earth, and the National Oceanic and Atmospheric Administration expects their combined arrival to push geomagnetic storm conditions to the G2 level on the evening of June 12, 2026. At that intensity, the aurora borealis can creep far enough south to become visible across parts of at least 11 northern-tier states, from Washington and Montana in the west to Maine and Vermont in the east, provided skies stay clear and viewers get away from city lights.
NOAA’s Space Weather Prediction Center (SWPC), the official U.S. government authority on space weather, issued a G2 (Moderate) geomagnetic storm watch tied to the incoming CME sequence. The watch means forecasters have enough confidence in the solar wind data streaming from sensors at the L1 Lagrange point, roughly a million miles sunward of Earth, to flag a likely Kp index of 6 on the planetary K-index scale. That is the threshold where aurora visibility begins to extend well below the Canadian border.
Where the three CMEs came from
All three eruptions originated from active regions on the sun’s Earth-facing disk during a stretch of heightened solar activity consistent with the ongoing peak of Solar Cycle 25. NASA’s DONKI database, maintained by the Community Coordinated Modeling Center, catalogs each event with its measured speed, direction, and angular width. WSA-ENLIL model runs linked to those catalog entries project that the three plasma clouds will arrive in relatively quick succession, with the possibility that a faster trailing CME overtakes and merges with a slower predecessor, a phenomenon known as CME cannibalism that can amplify the geomagnetic punch on arrival.
That stacking effect is what separates this event from a routine single-CME encounter. When compressed plasma and magnetic field from multiple eruptions pile into Earth’s magnetosphere within hours of each other, the sustained pressure can keep the aurora oval inflated at lower latitudes longer than any one impact would on its own. It is also what makes precise timing so difficult: arrival-window estimates from different research models can diverge by six hours or more, and the interaction physics add another layer of uncertainty.
Which states could see the aurora
During confirmed G2 conditions, SWPC’s OVATION Prime aurora model typically projects viewing probabilities that extend across the northernmost parts of Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan, New York, Vermont, and Maine. Those 11 states sit at or above roughly 45 degrees north geographic latitude, where the geomagnetic latitude is favorable enough for Kp-6 aurora to appear above the northern horizon.
A critical caveat: OVATION Prime regenerates its probability map every 30 minutes using live solar wind measurements. A promising map at 10 p.m. local time can flatten by midnight if the interplanetary magnetic field rotates northward, and a quiet map can light up within minutes if a CME shock arrives carrying a strong southward magnetic component. The 11-state footprint is a reasonable projection for G2 peak conditions, not a guarantee that every location within those borders will see color overhead.
For context, the massive G5 superstorm of May 2024 pushed aurora sightings as far south as Florida and Texas, an extreme that required Kp values near 9. Tonight’s forecast of Kp 6 is far more modest, so expectations should be calibrated accordingly. Displays at mid-latitudes during a G2 storm tend to hug the northern horizon and often appear as a pale greenish or grayish arc to the unaided eye, nothing like the sweeping curtains visible from Scandinavia or Alaska.
What G2 conditions actually mean
Beyond the visual spectacle, a G2 geomagnetic storm carries practical consequences for infrastructure. According to NOAA’s space weather scales, G2-level activity can trigger voltage alarms in high-latitude power systems, degrade high-frequency radio propagation at northern latitudes, and force orientation corrections for satellites in low-Earth orbit. Utility operators and satellite controllers monitor SWPC alerts in real time and have procedures in place for these scenarios, so widespread disruptions are unlikely but not impossible if conditions briefly spike above the forecast.
For the average person on the ground, a G2 storm poses no direct health or safety risk. There is no need for protective measures. The most practical step is to keep devices charged in the unlikely event of brief power fluctuations in northern regions and to stay tuned to SWPC updates for any escalation to G3 or higher.
How to actually see the northern lights tonight
Step one is checking SWPC’s real-time 30-minute aurora forecast after local sunset. If the model shows elevated probabilities over your area, head to the darkest location you can reach, ideally somewhere with an unobstructed view of the northern horizon and minimal light pollution. Even a 30- to 60-minute drive out of a metro area can dramatically improve your odds.
Patience is non-negotiable. Because the exact CME arrival time is uncertain, plan to spend at least an hour or two outside, scanning the northern sky periodically rather than expecting a single dramatic peak. Geomagnetic substorms can cause the aurora to brighten and ripple for 10 to 20 minutes before fading back to a diffuse glow. Many would-be viewers miss the show by stepping out for five minutes and giving up just before conditions surge.
Your smartphone can be a surprisingly useful tool. Long-exposure night modes on modern phones pick up auroral color and structure that the human eye struggles to detect at mid-latitudes, where displays are faint. If you see a suspicious pale arc to the north, point your camera at it and hold still for a few seconds. You may find vivid greens and purples on screen that your eyes registered only as a smudge of light.
Ground-level weather matters just as much as space weather. Thick cloud cover will block any aurora, and even scattered clouds can wash out faint structures. Check local cloud-cover forecasts and satellite imagery before committing to a drive, and be willing to adjust your location if a clearer gap opens up nearby.
When we will know if the forecast was right
The definitive answer will come from observed Kp data published through SWPC’s real-time feeds after the CME impacts register on ground-based magnetometers. If the planetary K-index sustains a value of 6 or higher for at least one three-hour reporting window overnight, the G2 forecast will be confirmed. If the CMEs arrive with weaker-than-expected southward magnetic fields, or if they spread apart rather than stacking, the storm could stall at G1 or even fizzle into minor unsettled conditions.
Space weather forecasting, like its terrestrial counterpart, is probabilistic. SWPC’s track record on G2 watches is solid but not perfect, and the added complexity of three interacting CMEs widens the range of possible outcomes. The data supporting tonight’s watch are credible, the agency issuing it is authoritative, and the aurora has a real chance of showing up across the northern United States. Whether the sky cooperates is the one variable no model can control.
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*This article was researched with the help of AI, with human editors creating the final content.
