Federal forecasters are warning that a powerful X-class solar flare could trigger strong radio blackouts and strain power grids across a swath of the United States, with 22 states in the potential impact zone. The alert centers on the risk of an R3-level event on the official radio blackout scale, a category that can disrupt communications and complicate grid operations for up to an hour at a time on the sunlit side of Earth. The warning comes as a broader January space weather onslaught pushes the current solar cycle toward some of its most intense activity yet.
NOAA’s R3 warning and the 22-state risk zone
Forecasters at the National Oceanic and Atmospheric Administration have been tracking an active region on the sun that recently produced a powerful X-class flare, the kind of eruption that can trigger an R3, or “strong,” radio blackout on the agency’s R1 to R5 scale. In guidance covering events expected on Monday and Tuesday, NOAA said the flare activity could reach that R3 threshold, with the potential to knock out high-frequency radio for up to an hour in some parts of Earth. That kind of disruption is not just a problem for hobby radio operators, it can interfere with aviation, maritime traffic and emergency services that rely on long-range communications.
The same solar outburst has also set up conditions for a geomagnetic storm that could light up the sky and unsettle infrastructure across a broad slice of the country. An Upgraded “Severe” Northern Lights Alert For 24 States Monday After Solar Flare, by Jamie Carter, Senior Contributor, described how the same eruption prompted a major aurora watch for 22 states from Monday through Tuesday, Jan, underscoring just how far south the effects could reach. That auroral footprint is a visual marker of the same geomagnetic disturbance that can induce currents in long power lines and transformers, a key reason grid operators are now on heightened alert.
From X-class flare to R3 blackout: how the storm unfolded
The current threat traces back to an X-class solar flare that erupted from the sun earlier in January, hurling a burst of energy and a huge coronal mass ejection toward Earth. Observers reported that the eruption triggered strong R3 radio blackouts across the sunlit side of Earth, with the most severe disruptions concentrated in regions directly facing the sun at the time. Those blackouts are the immediate, electromagnetic punch of a flare, distinct from the slower moving cloud of charged particles that drives geomagnetic storms when it slams into the planet’s magnetic field.
European monitors have been tracking the same sequence, noting that an X-class solar flare was observed on 18 January 2026 as part of a broader January 2026 space weather event. The European Space Agency reported that this eruption produced a high energy particle shower that affected satellites and highlighted the value of ground based space weather monitoring capabilities, a summary captured in its Jan update at 14:00 CET. That international picture reinforces the scale of the disturbance now bearing down on North America.
Severe, Solar Radiation Storm Progress and G4 geomagnetic Levels
While the R3 blackout risk has grabbed headlines, it is only one piece of a larger solar onslaught that has already pushed radiation and geomagnetic indices into severe territory. NOAA’s Space Weather Prediction Center reported an S4 category event, formally described as an S4 (Severe) Solar Radiation Storm in Progress, January 19th, 2026, with high energy particles flooding near Earth and threatening radio communications in polar regions, a status detailed in its Severe bulletin. S4 is the second highest level on the radiation storm scale, a reminder that airlines flying polar routes and satellites in high orbits are already dealing with elevated risk.
At the same time, Earth’s magnetic field has been hammered hard enough to reach G4 (Severe) Geomagnetic Storm Levels Reached 19 Jan, 2026, with G4 Levels first recorded that day and G4 levels remaining possible according to NOAA’s Geomagnetic Storm Levels alert. G4 storms are powerful enough to cause widespread voltage control problems and possible protective device trips on some power systems, which is why grid operators treat them as serious operational challenges rather than exotic space weather trivia.
When radio blackouts hit and why Strong storms rattle grids
To understand why an R3 event matters, it helps to look at what a strong solar flare does to the upper atmosphere. When a strong enough solar flare occurs, ionization is produced in the lower, more dense layers of the ionosphere (the D-layer), a process that increases radio wave absorption and can wipe out high frequency signals over a wide area, as explained in NOAA’s overview of When solar flares cause radio blackouts. That effect is what the R-scale is designed to capture, from minor R1 disturbances up to extreme R5 events that can cause complete HF radio loss on the entire sunlit side of the planet.
The radio blackout scale itself is calibrated to the intensity of X-ray emissions from the sun, with R3 “strong” events typically triggered by X1 to X9 flares. An explainer on how radio blackouts are measured notes that such events can cause transport authorities to lose contact with ships and planes, which may also experience loss of positioning based on satellite navigation, and that R3 conditions are triggered by X1-9 flares, a relationship laid out in a Nov analysis. For grid operators, that combination of communications loss and geomagnetic disturbance is exactly the kind of double hit that can make a difficult day much harder.
Strong geomagnetic storms may affect radio communication, reduce the signals used in navigation, and even cause the need to change flight paths, while also driving currents that make it harder to manage the voltage on long-distance transmission lines, according to a recent overview of how Strong storms put power grids and satellites on guard. Even less obvious is the way repeated storms can stress transformers over time, a slow burn risk that utilities are still learning how to quantify.
Northern Lights, While Earth weathers the storm
For many people, the most visible sign of this solar unrest has been the sky itself. An Upgraded “Severe” Northern Lights Alert For 24 States Monday After Solar Flare, by Jamie Carter, Senior Contributor, highlighted how auroras were forecast to spill far beyond their usual high latitude haunts, a reach that reflects the intensity of the underlying geomagnetic disturbance described in that Northern Lights Alert report. A separate account described how a Severe geomagnetic storm dazzles night sky with Northern Lights in many states across US, with Raymond Sanchez noting in an Updated Tue dispatch that the spectacle was driven by a coronal mass ejection (CME), a detail captured in the Northern Lights coverage.
Space weather trackers note that the sun is now well into Solar Cycle 25, with its magnetic field having reached solar maximum in October 2024 and continuing to emit strong solar activity that fuels the most recent CME, as summarized in an Jan briefing. While Earth’s magnetic field is under effects of fast solar wind from a large coronal hole, the sun shows off filaments and active regions that keep auroras dancing across high latitudes, a pattern described in a While Earth update. That same solar restlessness is what now has utilities and satellite operators bracing for the next wave.
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