A major solar storm warning is in effect as a powerful coronal mass ejection (CME) — described by forecasters as a possible “cannibal CME” — barrels toward Earth, raising the chance of spectacular northern lights over the Labor Day weekend. The forecast also has utilities, satellite operators, and GPS-dependent industries on alert as space-weather agencies monitor the event in real time.
The phenomenon was triggered by a long-duration M2.7 flare from sunspot Active Region 4199 yesterday. The eruption sent a fast-moving coronal mass ejection (CME) toward our planet, which is expected to arrive late on September 1 and into early September 2.
solar storm warning
What happened on the Sun — and why forecasters are concerned
Solar observatories recorded a long-duration M2.7 flare from Active Region 4199 on Aug. 30. Coronagraph imagery showed a full-halo, asymmetric CME leaving the Sun shortly after the flare — an indication the eruption is largely Earth-directed. Early model runs suggest a second eruption may be following closely behind the first. When one CME catches up to and merges with an earlier one, scientists call the combined structure a “cannibal CME,” a configuration that can intensify the magnetic field delivered to Earth and increase the potential for strong geomagnetic storms.
Why does merging matter? The severity of geomagnetic storms depends heavily on the CME’s magnetic orientation when it hits Earth. A prolonged southward (negative) magnetic field component enables stronger interaction with Earth’s magnetosphere, which can amplify auroras and increase the chance of impacts to technology.
NOAA: G2 → G3 forecast and what that means
The National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center has predicted that the CME will trigger a G2 (moderate) geomagnetic storm upon its arrival. The conditions are expected to worsen into a G3 (strong) storm as the bulk of the solar event passes on September 2. This could result in auroras being visible further south than usual across parts of the northern US, including states like Oregon, Illinois, and New York.
NOAA’s G-scale runs from G1 (minor) to G5 (extreme). A G2 storm can cause short-term HF radio fading and minor power system fluctuations; a G3 storm raises the risk of longer HF radio blackouts, more pronounced GPS errors, and stronger geomagnetically induced currents that can affect pipelines and some power-grid components. Operators of satellites, airlines on polar routes, and utilities typically treat a G3 forecast as a cue to increase monitoring and mitigation activity.
Where and when to look for the auroras
Models and official forecasts show the CME’s leading edge arriving late on Sept. 1 (UTC) with the primary impact window extending into Sept. 2 — timing that places peak geomagnetic activity over the Labor Day holiday for many U.S. time zones. If the storm’s magnetic orientation is favorable (southward), auroras may be visible unusually far south across the northern tier of the United States. Recent mapping suggests visibility could extend from Alaska to Illinois and into pockets of the Northeast under clear, dark skies.
Keep in mind: moon phase, cloud cover, and light pollution strongly affect what you’ll see. A bright waxing gibbous moon around these dates may wash out fainter displays; the best viewing is from rural, high-latitude locations away from city lights.
While many will watch the sky for a light show, even a G2–G3 storm carries real risks for infrastructure:
Satellites: Increased atmospheric drag at low Earth orbit can require extra maneuvers; instrumentation and communications can see intermittent anomalies.
Radio & navigation: HF radio used in aviation and maritime communications can fade or blackout; GPS position and timing can degrade.
Power grids: Geomagnetically induced currents (GICs) can stress transformers and long transmission lines; grid operators may enact precautionary measures when forecasts spike.
SWPC (NOAA) and comparable international agencies issue watches, warnings, and actionable guidance so affected industries can prepare. The agency’s 3-day forecast and alerts pages are the best sources for real-time updates.
Solar cycle context
The Sun is moving through heightened activity as it approaches solar maximum — the natural peak in the ~11-year solar cycle — which increases the frequency of flares and CMEs. While most space-weather events only produce memorable auroras, some larger, Earth-directed CMEs during solar maximum can create notable technological disruption, reinforcing the value of timely solar storm warning systems.
Platform X reaction — on the record
Social platforms are buzzing as the forecast circulated. A trending post captured under the Platform X label read:
USER 1 writes “It might already be too late… Solar Storm Coming – Direct Shot By The Sun
USER 2 writes “A severe solar storm could cause a lot of damage, not only to GPS, but also to the industrial world’s electric power grid, telephone, lines, and Internet switching, all of which rely on GPS for timing information.”
USER 3 writes “Texas has faced grid challenges, like the 2021 storm, leading to outages. However, 2025 reports show improvements via batteries and solar storage (NERC, TRE). California, with high rates, also sees frequent outages from wildfires. Reliability varies; Texas ranks high in outage risk but has lower average prices.”
User 4 writes “That being said, insurance companies agree to pay for damages to solar panels but not caused by them. Damage caused by falls under homeowners maintenance. Damages from a storm is covered. Choose your contractors wisely as not all are the same.”
User 5 writes “I’ve had Tesla Solar in Florida since 2020 and they have endured many hurricanes, including Hurricane Ian in 2022 that decimated the area. The funny thing is, the only section of my roof that didn’t have solar panels is the area that leaked after a storm. One solar panel was cracked and Tesla replaced it for me. If that solar panel wasn’t there I’m positive the roof would have been damaged instead.”
Image taken from X shared by user 5
Guidance for the public
Skywatchers: For aurora updates, monitor NOAA’s Aurora Dashboard and community reporting pages. Dress warmly, escape city light, and bring a camera with manual exposure settings to capture faint displays.
Travelers & pilots: Airlines and air traffic authorities may issue guidance for polar routes that rely on HF communications. Check official flight advisories before travel.
Homeowners & businesses with solar: Check your contractor’s warranties and insurance policies before the storm; keep devices and backups secure and be ready for localized power disturbances. (Public commentary above reflects user experiences, but consult your insurer and installer for policy details.)
Critical infrastructure operators: Follow SWPC alerts and technical briefings. Utilities and satellite operators should be prepared to implement mitigation procedures.
This solar storm warning is a timely reminder that space weather is both beautiful and consequential. Forecasters at NOAA’s Space Weather Prediction Center currently expect initial G2 (moderate) geomagnetic activity that could intensify to G3 (strong) as the storm’s main portion passes — bringing a real chance of widespread auroras and a need for readiness among industries that depend on radio, GPS, and the electric grid. Monitor NOAA SWPC and trusted space-weather outlets for live updates as the event unfolds.
FAQs
Q1: What is a solar storm warning? A solar storm warning is issued when space-weather agencies detect a significant coronal mass ejection (CME) or solar flare heading toward Earth. This alert informs the public and critical industries about potential geomagnetic storms that could affect satellites, GPS systems, and power grids.
Q2: How does a solar storm warning affect aurora visibility? When a solar storm warning is in effect, the likelihood of visible northern or southern lights increases. Strong geomagnetic storms, especially from a “cannibal CME,” can extend aurora visibility further south than usual, providing a spectacular sky show.
Q3: Who should take precautions during a solar storm warning? Airlines, satellite operators, power-grid managers, and GPS-dependent industries must monitor a solar storm warning closely. Homeowners with solar panels and electronic devices may also experience minor disruptions, making preparedness essential.
Q4: When should I expect impacts from a solar storm warning? Impacts usually begin when the coronal mass ejection (CME) reaches Earth, often within 1–3 days after the initial solar flare. Forecasts from NOAA and other space-weather agencies provide the most accurate timing for when a solar storm warning may affect satellites, communications, and power systems.
Q5: Can a solar storm warning disrupt daily life? Yes. While most people will only see auroras, a strong solar storm warning can cause GPS inaccuracies, HF radio blackouts, and minor power fluctuations. Travelers, pilots, and industries reliant on electronic infrastructure should stay alert during the warning period.
Q6: How can I safely observe auroras during a solar storm warning? To safely enjoy auroras, follow the official solar storm warning updates, avoid city light pollution, dress warmly, and use a camera with manual settings to capture faint displays. Rural, high-latitude locations provide the best viewing opportunities.
