Copyright Newsweek
Warnings have been issued for portions of the United States’ electric power grid amid a forecasted severe geomagnetic storm. The Space Weather Prediction Center (SWPC) of the National Oceanographic and Atmospheric Administration (NOAA) issued the forecast on Tuesday, saying a geomagnetic storm at a strength of category G4 would cause issues with electrical grids for states poleward of the 45th parallel. States north of that latitude include Oregon, Idaho, Montana, South Dakota, Minnesota, Wisconsin, Michigan, New York, Vermont, New Hampshire and Maine. Newsweek reached out to NOAA via email for comment. Why It Matters Power grid stability underpins everyday life in the U.S., ensuring homes and businesses have reliable electricity. As solar activity threatens to disrupt electrical and communications infrastructure, officials must rapidly respond to risks of large-scale outages and equipment failure. The recent warnings come as demand for energy surges to levels not seen in over a decade, driven by both climate-related challenges and the expanding footprint of AI-powered data centers and advanced manufacturing. The Department of Energy and independent grid operators said in a July press release that without swift intervention and updated infrastructure, certain U.S. regions could face substantially more power interruptions in the years ahead, threatening critical services and economic resilience. What To Know The NOAA issued ongoing space weather alerts in 2025, noting that solar activity, including minor radio blackouts (R1 level), could cause voltage control problems and contribute to grid instability. Such events can lead to protective systems inaccurately tripping critical assets, compounding operational challenges for grid managers. The geomagnetic storm forecast for this week is expected to reach a strength of G4 and above, indicating that the impacts could be severe. "Possible widespread voltage control problems and some protective systems may mistakenly trip out key assets from the power grid," the forecast from NOAA said. It also warned that satellite systems could be "degraded or inoperable for hours." An aurora borealis, also known as the northern lights, may be seen as far south as Alabama on Tuesday night due to the storm. What Is a Geomagnetic Storm? A geomagnetic storm is a major disturbance of Earth's magnetosphere caused when intense solar wind and magnetic fields from the sun interact with Earth's own magnetic field, transferring vast amounts of energy into the planet's near-space environment, according to SWPC. Major drivers of these storms include coronal mass ejections, huge clouds of charged particles from the sun that can reach Earth within hours. When these particles strike Earth, they can cause intense currents in space and generate magnetic disturbances at the surface, sometimes visible as bright auroras. These storms can disrupt navigation and radio systems through ionosphere heating and induce geomagnetic currents in long-distance transmission lines or pipelines, potentially causing voltage control issues, tripping of safety equipment, and even large-scale power outages in extreme cases. NOAA issues alerts and warnings using a standardized scale, with potential impacts ranging from minor communication disruptions to more severe risks affecting navigation and infrastructure. What People Are Saying The Space Weather Prediction Center said: "During storms, the currents in the ionosphere, as well as the energetic particles that precipitate into the ionosphere add energy in the form of heat that can increase the density and distribution of density in the upper atmosphere, causing extra drag on satellites in low-earth orbit. The local heating also creates strong horizontal variations in the in the ionospheric density that can modify the path of radio signals and create errors in the positioning information provided by GPS. While the storms create beautiful aurora, they also can disrupt navigation systems such as the Global Navigation Satellite System (GNSS) and create harmful geomagnetic induced currents (GICs) in the power grid and pipelines." What Happens Next The SWPC will continue to monitor conditions of the geomagnetic storm and provide updates on possible impacts.
