Multiple CMEs Converge on Earth
Space weather forecasters at NOAA's Space Weather Prediction Center issued a geomagnetic storm watch late Wednesday as a series of coronal mass ejections launched earlier in the week made their journey across the 93-million-mile gap between the Sun and Earth. When several CMEs arrive in close succession, their interaction with Earth's magnetosphere can be significantly stronger than a single ejection would produce, creating the conditions for extended and geographically widespread aurora events.
The storm is expected to peak at G3 intensity on the NOAA geomagnetic storm scale—classified as strong—with brief periods potentially reaching G4, or severe, levels during the most active phases. At G3 intensity, aurora is reliably visible from latitudes as far south as Oregon and Illinois under clear skies. At G4, the display can extend into states more commonly associated with warmer weather.
Where to Look and When
The prime viewing window on the night of March 19 runs from roughly 10 PM to 2 AM local time across most viewing areas, though the geomagnetic activity may produce displays earlier and later. Observers should face north and allow their eyes to dark-adapt for at least fifteen minutes before concluding there is nothing to see—aurora can be faint and greenish at southern margins of the viewing range, easily mistaken for light pollution until the eye adjusts.
The 18 states where aurora may be visible under clear skies span from Alaska and the Pacific Northwest through the upper Midwest and into the mid-Atlantic. Alaska offers the best odds; even during moderate solar activity, aurora is frequently visible there. For observers in Minnesota, Wisconsin, Michigan, and the Dakotas, this event represents one of the better aurora opportunities of the current solar cycle. Camera sensors are significantly more sensitive to aurora than the human eye, meaning smartphone long exposures may capture striking images even where direct observation shows little.
The Science of the Solar Maximum
The frequency and intensity of aurora events in 2025 and 2026 is not coincidental. The Sun operates on an approximately eleven-year cycle of magnetic activity, with Solar Cycle 25 having reached and now beginning to pass its peak activity level. Near solar maximum, sunspot counts are highest, coronal mass ejections are most frequent, and the strongest geomagnetic storms are most likely to occur.
Astronomers tracking Solar Cycle 25 have noted that the cycle has exceeded initial predictions for its strength. What was anticipated to be a moderate cycle has produced more intense activity than models suggested, contributing to the unusual frequency of significant aurora events visible at mid-latitudes over the past eighteen months. The May 2024 storm that produced aurora visible across much of the continental United States and parts of Mexico was the strongest single event in about two decades.
Infrastructure Impacts
Strong geomagnetic storms are not only aesthetically striking—they carry practical consequences for technological infrastructure. The same magnetic field disturbances that produce aurora can induce currents in long electrical conductors, including power grid infrastructure and pipelines. NOAA has issued advisories for grid operators, advising enhanced monitoring during the storm's peak.
GPS accuracy can also degrade during significant geomagnetic storms because ionospheric disturbances affect GPS signal propagation. Aviation routes that pass through high latitudes—particularly polar routes between North America and Asia—may be adjusted to avoid regions of most intense ionospheric activity. High-frequency radio communications, still used extensively in aviation and maritime operations, can be disrupted or blacked out entirely during the most intense phases as the ionosphere becomes unreliable for signal reflection.
Viewing Tips
For the best chance of seeing aurora, observers should find the darkest sky accessible within a reasonable drive from their location. Rural areas away from city lights, elevated terrain that reduces the horizon-level light dome from nearby towns, and locations with unobstructed northern horizons all improve the experience. Weather forecasts show clear skies across much of the upper Midwest and Pacific Northwest tonight, which are also the regions with the highest aurora probability. The current solar cycle's active phase is expected to continue through at least mid-2026, so tonight's event is unlikely to be the last opportunity this year for mid-latitude aurora viewing.
This article is based on reporting by Space.com. Read the original article.
