A powerful M8.46-class solar flare erupted from the Sun’s surface on June 15, disrupting high-frequency radio communications across North America and sparking warnings of further geomagnetic activity later this week.
At a Glance
- M8.46 solar flare erupted from sunspot AR4114, nearing X-class strength
- High-frequency (HF) radio blackouts occurred across North America’s sunlit regions
- NOAA expects a glancing coronal mass ejection (CME) impact around June 18
- Risk of G1 geomagnetic storm and auroras over the northern U.S.
- Experts warn of potential infrastructure disruption if larger solar storms follow
Flare Slams Earth, Disrupts Communications
At 2:25 p.m. EDT on June 15, sunspot AR4114 unleashed an M8.46-class flare, causing a sudden pulse of X-ray and ultraviolet radiation to ionize Earth’s upper atmosphere. The result was a widespread high-frequency blackout, affecting signals below 20 MHz used in aviation, marine navigation, and ham radio.
According to NOAA’s Space Weather Prediction Center, the flare impacted communications from coast to coast, primarily on the sunlit side of the planet. Similar events have previously forced emergency reroutes of polar airline flights and degraded GPS signals.
Watch a report: Solar Flare Triggers Radio Blackouts Across North America
CME En Route — Aurora Watch Issued
The solar flare also launched a coronal mass ejection, or CME, expected to deliver a “glancing blow” to Earth around June 18. NOAA models predict a G1 (minor) geomagnetic storm, with a chance of auroras visible as far south as Wisconsin, New York, or Maine. Space weather scientists say these mild effects could intensify depending on CME speed and direction.
A Stark Reminder of Solar Risk
This event serves as a warning about Earth’s vulnerability to space weather. Scientists have long cautioned that a flare on par with the 1859 Carrington Event—or even the 1989 Quebec blackout—could cripple modern infrastructure reliant on satellites and grid connectivity.
NASA and NOAA are now expanding early-warning protocols and grid hardening studies, though recent federal simulations suggest the U.S. remains underprepared for a high-magnitude solar storm.
As Solar Cycle 25 approaches its peak, incidents like this could grow in frequency and severity. Public and private sectors are racing to improve resilience—before the next superstorm hits.
